Hydrogen production from water by solid oxide electrolysis

Hydrogen production from water by solid oxide electrolysis

Solid oxide electrolysis cell (SOEC) is a high-temperature water electrolysis technology that uses YSZ and other materials as electrolytes to produce hydrogen through anode and cathode reactions. It has the advantages of low power consumption and high efficiency, and is suitable for waste heat recovery, but faces high cost and stability challenges.

Solid oxide electrolysis of water to produce hydrogen is a high-temperature water electrolysis technology. From the technical principle, SOEC can be divided into oxygen ion conduction SOEC and proton conduction SOEC.

(Oxygen ion conduction SOEC working principle)

(Working principle of proton-conducting SOEC)

Oxygen ion conducting SOEC uses solid oxide as electrolyte, and the following chemical reactions occur at the anode and cathode respectively:
Anode: 2O²ˉ=O2+ 4e-
Cathode: 2H2O+4e-=2H2+2O²ˉ

The core components of SOEC include dense electrolyte and porous electrode, where the electrolyte is usually yttria stabilized zirconia (YSZ) material. At high temperatures of 600 to 1000°C, YSZ has excellent ionic conductivity and thermochemical stability, making it the preferred electrolyte material for SOEC.

In addition to YSZ, some other materials are also widely used in SOEC electrolytes. For example, scandia stabilized zirconia (ScSZ) and cerium oxide-based electrolytes, these materials also show good performance under certain conditions. In addition, lanthanum gallate-based electrolytes are gradually gaining attention, and the application of these materials provides a variety of choices for SOEC electrolytes.

In terms of electrode materials, hydrogen electrodes usually use Ni-YSZ metal ceramic composites, which not only have good conductivity, but also provide sufficient catalytic activity to promote hydrogen generation. Oxygen electrodes mostly use composites of strontium-doped lanthanum gallate (LSM) and YSZ, which can effectively catalyze oxygen generation and maintain stability at high temperatures.

The structure of SOEC is mainly divided into two types: tubular and flat. Tubular SOEC is the earliest type to be studied. Its main advantage is that it does not require additional sealing materials and the connection method is relatively simple. However, tubular SOEC also has disadvantages such as high cost and low power density. In contrast, flat SOEC has the advantages of high power density and low cost, so it has become a hot spot in current research. However, flat SOEC has great challenges in sealing, and it is necessary to overcome the stability of sealing materials under high temperature conditions.

The operating temperature of SOEC is usually as high as 600 to 1000℃, and the enthalpy of high-temperature water vapor is high, so the electrolysis voltage of SOEC can be as low as 1.3V, while the electrolysis voltage of alkaline electrolysis or proton exchange membrane (PEM) electrolysis is usually above 1.8V. Therefore, SOEC has obvious advantages in power consumption. Under the condition of minimum power consumption, 3kWh of electricity can produce 1 standard cubic meter of hydrogen. However, SOEC requires additional energy consumption to produce high-temperature water vapor, which has unique advantages in some special application scenarios, such as nuclear power hydrogen production.

Although SOEC has obvious advantages in power consumption and efficiency, its high operating temperature also brings some challenges and problems. The first is the cost issue. The cost of high-temperature materials and manufacturing processes is high. The second is the long start-up and shutdown time. Since SOEC needs to reach high temperature to operate, its startup and shutdown process is relatively slow. In addition, cycle life is also a key issue that needs to be solved. Under high-temperature operating conditions, the stability and durability of the material are facing challenges.

At present, the solid oxide water electrolysis hydrogen production technology is still in the demonstration and verification stage, and has not yet been realized in large-scale commercial applications. Despite the many challenges, SOEC technology has shown great potential in specific areas. For example, in the utilization of waste heat from nuclear power plants and high-temperature industrial waste heat recovery, SOEC technology can effectively convert these high-temperature heat sources into hydrogen, thereby achieving efficient utilization and conversion of energy.

In the future, with the continuous progress of materials science and manufacturing processes, SOEC technology is expected to overcome the current technical bottlenecks and achieve higher efficiency and lower costs. Further research and development will focus on improving the performance of electrolyte and electrode materials, extending the service life of equipment, and optimizing the overall design and operating parameters of the system. Through multi-faceted improvements and innovations, SOEC technology is expected to occupy an important position in the future hydrogen economy and become an important means of renewable energy utilization and hydrogen production.

Methods for improving low temperature performance of flow batteries

Methods for improving low temperature performance of flow batteries

The efficiency of liquid flow batteries will be significantly reduced at low temperatures, and divalent vanadium ions will precipitate in vanadium electrolytes at low temperatures, seriously affecting battery performance and life. The main factors causing poor performance of liquid flow batteries at low temperatures are:

1. At low temperatures, the viscosity of the electrolyte increases, resulting in reduced conductivity;

2. At low temperatures, the charge transfer impedance at the electrode/diaphragm interface increases;
At low temperatures, the migration rate of active substances in the electrolyte decreases, and the electrode polarization increases.
Effective methods to improve the low-temperature performance of flow batteries are proposed mainly from the aspects of electrodes, electrolytes, and operating parameters.

1. Electrodes

As the reaction site of active substances, the electrode's activity, conductivity, compressibility, porosity, permeability and other performance parameters are directly related to the performance of the battery stack. Among them, the electrode activity is most significantly affected by temperature. In vanadium flow batteries, the poor activity of the negative electrode is the main factor restricting the further improvement of the performance of vanadium flow batteries. At present, most flow battery electrodes use graphite felt as electrodes. Graphite felt is a porous material.

As an electrode, it can increase the specific surface area of the electrode and can also be used as a diffusion layer. Ordinary graphite felt has poor electrode activity. Even after high-temperature treatment, the electrode activity cannot be well exerted. At present, the main research work is focused on electrode modification and modification, especially the activity of the negative electrode needs to be improved.

The main way to improve the electrochemical activity of negative electrode materials at low temperatures is to modify the electrodes. The electrodes are modified with catalysts (such as TiN nanowires, TiC, MnO2, OTiB2, TixOy), and the electrode activity is improved by surface coating and deposition on the electrodes, which reduces the electrochemical polarization of the battery and the side reactions of the battery at the end of charge and discharge.

2. Electrolyte

As the storage place for active substances in flow batteries, the electrolyte is the capacity unit of flow batteries. The conductivity of the electrolyte increases with increasing temperature, and the viscosity decreases with increasing temperature. The comprehensive performance of the battery can be optimized by increasing the comprehensive valence state of the electrolyte and increasing the volume of the negative electrode electrolyte. See the influence of the state of the negative electrode electrolyte of the flow battery on the battery performance.

For vanadium battery electrolytes, the negative electrode electrolyte is easy to precipitate at low temperatures, the stability of the negative electrode electrolyte is poor at low temperatures, and the viscosity increases and the conductivity decreases. At present, the main ways to improve low-temperature performance through electrolytes are:

1) Optimizing the solvent composition, by optimizing the sulfuric acid-vanadium ion concentration ratio, to improve the stability of the negative electrode electrolyte at low temperatures;
2) Developing mixed acid electrolytes, such as hydrochloric acid-sulfuric acid system vanadium electrolytes.
3) Additives, such as inorganic salts, organic acids, etc., through additives, destroy the precipitation/precipitation mechanism to increase the precipitation/precipitation barrier.

3. Operation parameters
The operation parameters of flow batteries mainly include charge and discharge mode, electrolyte flow rate, temperature, SOC, etc. The performance of flow batteries can be improved by adjusting and optimizing the operation parameters. For example, at the end of charge and discharge, the electrolyte flow rate is increased to increase the battery capacity and electrolyte utilization.

The main ways to improve the performance of flow batteries at low temperatures by optimizing the operation parameters are:

1) Increase the electrolyte flow rate, actively increase the diffusion of the electrolyte, reduce the concentration polarization of the electrolyte on the electrode, reduce the diffusion impedance, and improve the performance of the flow battery;

2) Control the SOC and operate the flow battery at a low SOC as much as possible. At low temperatures, the stability of the negative electrode electrolyte deteriorates. By reducing the concentration of divalent vanadium ions at the negative electrode, the risk of divalent vanadium ion precipitation is reduced;

3) Reduce the charge and discharge density (power). At low temperatures, the electrochemical performance decreases, and there is a risk that the liquid flow battery cannot operate normally under high density. By controlling the charge and discharge mode, high-power (density) charging and discharging is not performed at low temperatures. After running for a period of time, the heat generated is used to increase the temperature before high-power charging and discharging.

Research on Effective Development Methods for Ultra-thin Heavy Oil Reservoirs

Research on Effective Development Methods for Ultra-thin Heavy Oil Reservoirs

The Saertu heavy oil reservoirs in the WE block of Daqing are low-abundance ultra-thin heavy oil reservoirs.Only small -scale steam stimulation field tests have been carried out before.The degree of development is low，and the economic benefits are not up to standard，so an effective development technology system is not formed.The well pattern and effective producing mode of different sand body scales are unclear.

There-fore，based on the flow characteristics of reservoir fluid, core flooding experiments, numerical simulation, and economic evaluation research are conducted to compare and analyze the development effects of elastic developmen, hot water flooding, steam stimulation，elastic development to steam stimulation, and steam flooding. The optimization design method of development methods and the well patterns of ultra-thin heavy oil reservoirs are established. The well-controlled reserves of vertical and horizontal wells under different channel sand body scales are evaluated，and the technical and economic well spacing of varying development methods is calculated.The results show that the effective period of elastic development is 240 to 300 days, the recovery rate of elastic development to steam stimulation is higher, and its internal rate of return is the highest. The research results are used to guide the preparation of a well development plan for the block in four phases, 493 development wells (155 horizontal wells) are designed with a designed productivity of 32.59×104 t.

The horizontal wells were deployed in areas where the river width exceeds 250m and the effective thickness exceeds 2.3m. The vertical wells were deployed in areas where the river width is less than 250m and the effective thickness exceeds 2.7m. A well spacing of 140m is designed, and the development method of early elastic development and later steam stimulation is adopted. So far, 292 wells have been drilled and put into production, with a cumulative oil production of 32.7 ×104 t, achieving increased reserves, construction of production, and oil production in the same year.

Thermal management of flow batteries

Liquid flow batteries (RFBs) generate a lot of heat during operation. If the heat cannot be dissipated in a timely and effective manner, the battery temperature will rise, thus affecting the battery performance and safety. The electrochemical reaction conditions, ion conductivity, the rate at which ions move across the membrane, and the viscosity of the electrolyte are all closely related to the temperature during operation. Specifically, increasing the temperature can increase the reaction rate constant and promote the reaction kinetics in the electrochemical reaction. At the same time, high temperature will also reduce the viscosity of the electrolyte, thereby increasing the transmission efficiency of vanadium ions from the main body to the electrode surface and reducing the concentration polarization potential. However, when the temperature exceeds a certain range, it will have a fatal effect.

Taking the vanadium redox flow battery (VRFB) as an example, its normal operating temperature range is 0~40°C. As the temperature increases, the hydrogen evolution reaction on the negative electrode will be significantly enhanced, resulting in a decrease in Coulombic efficiency. At the same time, the diffusion ability of vanadium ions through the ion membrane is enhanced, which intensifies the capacity fading. In addition, the vanadium active ions in the electrolyte are unstable and prone to precipitation when the temperature is abnormal. When the electrolyte of 2 mol/L VO+2+3 mol/L H2SO4 is placed at 40°C for 2 days, the VO+2 Converted into V2O5 precipitation; and after being placed at 15°C for 7 days, V2+ in the electrolyte will precipitate. This generated precipitate will block the flow channel, cover the carbon felt and ion membrane, lead to increased pump power loss and battery failure.

Sustained high temperature will also accelerate the aging of the internal electrodes, proton membrane and other materials of the battery, thus shortening the service life of the battery. Therefore, temperature thermal management is of great significance to maintaining the stable operation of flow batteries.

In order to ensure the stable and safe operation of flow batteries, it is necessary to establish a thermal model to predict and control the temperature of the electrolyte and further guide battery optimization control, which is also an important part of the thermal management system.

The factors that generate heat during the operation of all-vanadium liquid flow batteries include electrochemical reactions, overpotential, hydraulic friction, cross-reactions and shunts, among which electrochemical reactions and overpotential heat generation account for a larger proportion compared to the other three.

At present, the thermal management technology routes of electrochemical energy storage systems are mainly divided into four categories: air cooling, liquid cooling, heat pipe cooling and phase change cooling. The mainstream technology routes for thermal management of liquid flow battery energy storage in the market are air cooling and liquid cooling. The choice of these heat dissipation methods depends on the scale, design, operating conditions and cost-effectiveness of the battery.

1) Air cooling

Air cooling is wind cooling, which uses air as a medium to remove the heat inside the system by heat conduction and heat convection, thereby cooling the system. Air cooling is divided into natural air cooling and forced air cooling according to the driving mode. Natural air cooling uses natural conditions such as natural wind pressure, air temperature difference, and air density difference to achieve a cooling effect on the battery.

The convection heat transfer coefficient of natural air cooling is much lower than that of forced air cooling, so it is difficult to completely dissipate the heat generated by the battery. For low-rate charge and discharge of the battery, the system temperature can be controlled within a certain temperature range, but the increase in the system current density can easily cause the temperature to exceed the limit range. Therefore, although natural air cooling has the advantages of simplicity, lightness and low cost, its scope of application is extremely small and it is rarely studied now. Forced air cooling is to take away heat through forced airflow generated by a blower or fan. At this time, the heat transfer coefficient of the forced airflow is greatly improved. Compared with liquid cooling, air cooling has the advantages of simple structure, easy maintenance and low cost, but it requires a certain amount of electricity, and the heat dissipation efficiency, heat dissipation speed and temperature uniformity are poor. It is usually suitable for small or medium-sized battery systems.

2) Liquid Cooling

Liquid cooling (liquid cooling) uses coolant as the medium and utilizes higher specific heat and heat transfer coefficient to dissipate heat. Liquid cooling systems can provide higher heat dissipation efficiency and better temperature control effects, but the system complexity and cost are also relatively high, and are suitable for large battery systems. Commonly used coolants include water, ethylene glycol aqueous solution, pure ethylene glycol, air conditioning refrigerant, and silicone oil. Since the charge in the electrolyte of the flow battery easily flows along the coolant to the entire system, it is more dangerous, so the choice of cooling medium is also very important. However, the most common method for flow batteries is to use corrosion-resistant and non-conductive heat exchangers. The internal materials are generally the same as those of the electrolyte storage tanks, using PVC or PP, or using titanium metal tubular heat exchangers, and the inner surface is covered with a corrosion-resistant TiO2 layer to protect the heat exchanger from sulfuric acid corrosion.

As one of the most promising renewable energy storage technologies, the overheating problem of vanadium flow battery during operation greatly affects the efficiency and stability of the system. Therefore, various feasible methods are needed to provide a feasible solution for the VRFB thermal management system.

The Science Behind Solar Powered Motion Sensor Lights

Solar-powered motion sensor lights have transformed outdoor illumination by merging energy efficiency, convenience, and safety. What makes these lights so groundbreaking? Beneath their modern designs lies intriguing technology that harnesses solar energy while ensuring they function effectively during nighttime.

At the core of these solar powered lights is the photovoltaic panel, which collects sunlight throughout the day and converts it into electricity. This energy is stored in rechargeable batteries, making sure the lights are ready to operate once it gets dark. Notably, these systems have become highly efficient, with contemporary PV panels capable of working even on overcast days, guaranteeing consistent performance regardless of the weather.

The inclusion of motion sensors adds a smart element to these lights. Utilizing passive infrared technology, the sensors can detect heat from moving objects. When movement is sensed, the lights immediately illuminate the area, improving visibility and discouraging potential intruders. This feature is not only useful but also energy-efficient, as the lights remain off when not in use.

solar powered motion sensor lights

Modern solar motion sensor lamps frequently offer customizable options, enabling users to modify sensitivity, brightness, and duration or operation. Some models even include ambient light sensors, ensuring they activate only in complete darkness. Together, these features make the lights versatile for various settings, from suburban gardens to busy urban areas.

Solar powered motion sensor lights exemplify sustainable innovation. They decrease dependence on conventional energy sources, reduce electricity costs, and provide an environmentally friendly alternative to traditional lighting. Beyond their practicality, they signify progress toward greener living, seamlessly integrating technology with ecological responsibility.

Solar Lights Do is a company that focuses on producing and selling premium-quality solar lights. We provide a diverse selection of efficient and durable solar lighting solutions designed for outdoor applications. If you’re interested, please visit us at www.solarlightsdo.com.

Innovative Solar Light Mounting Options

Solar lighting technology has become essential in contemporary outdoor design, providing energy efficiency, easy installation, and visual appeal. With a variety of mounting options available, choosing the right solar lights for your area is simpler than ever. Whether you need to illuminate a pathway, improve security, or brighten outdoor seating areas, the appropriate mounting option guarantees both functionality and style.

For locations such as entrances, garages, or patios, wall mounted solar lights are an excellent option. These lights are designed for easy attachment to walls, seamlessly integrating with architectural elements while delivering sufficient brightness. Many wall-mounted models come equipped with motion sensors for enhanced security and customizable settings to match your lighting needs. Their elevated position allows for extensive coverage without taking up ground space, making them perfect for smaller areas.

If flexibility is desired, solar ground plug lamps provide ultimate convenience. These lights are easy to install and move because of their robust ground stakes. They are perfect for lighting garden paths, flowerbeds, or driveways, adding both practicality and charm to outdoor environments. With no wiring needed, solar ground plug lamps are also an environmentally friendly way to illuminate landscaping without disturbing its natural aesthetics.

wall mounted solar lights

For larger outdoor lighting requirements, such as parking lots or community areas, solar street lights with pole installation are an excellent choice. Built for durability and high performance, these lights offer bright, dependable illumination. Their pole-mounted design maximizes light distribution, while integrated solar panels and energy-efficient LEDs reduce maintenance needs. These solar street lights are a practical solution for improving safety in both public and private areas.

When it comes to high-quality solar lighting, SLD, Solar Lights Do, is a reputable brand. They offer a diverse range of innovative products that combine advanced technology with modern design to cater to various outdoor lighting requirements. Whether you are looking for wall-mounted lights, ground plug lamps, or pole-mounted street lights, SLD guarantees outstanding performance and durability. Visit www.solightsdo.com to explore complete product range and see how solar lighting can enhance space.

The Future of Solar Energy in Outdoor Lighting

Solar energy is revolutionizing outdoor lighting by providing an environmentally friendly and economical alternative to conventional lighting. Thanks to improvements in solar panel efficiency, battery technology, and LED lighting, solar-powered fixtures are increasingly favored for for gardens, parks, pathways, and public areas.

The attractiveness of solar energy stems from its sustainability. Outdoor solar lights collect sunlight during the day and convert it into electricity to illuminate LEDs at night. This process eliminates the need for wiring, cuts energy costs, and reduces carbon emissions. As awareness of environmental issues rises, solar powered lighting is becoming a key component of urban planning and landscape architecture.

solar powered outdloor lamps

Contemporary solar outdoor lighitng systems come with features such as motion sensors, adjustable brightness settings, and smart controls that enable users to tailor lighting schedules. Improvements in battery technology have enhanced energy storage, allowing lights to operate effectively even on cloudy days or during prolonged use. Additionally, advancements in solar panel design have boosted their efficiency, resulting in smaller and more visually appealing lights.

Solar lighting has expanded beyond residential applications. It is now commonly used to light up walkways, parking lots, sport fields, and even remote locations with limited electricity access. The ease of installation without extensive groundwork makes these lights suitable for both temporary and permanent setups.

SLD, Solar Lights Do, is a company that focused on producing and selling high-quality solar powered outdoor lamps. We provide a diverse selection of efficient and durable solar lighting solutions for outdoor applications. If you’re interested, please visit us at www.solarlightsdo.com.

Advantages of CONSNAN Outdoor Telecom Cabinet

CONSNANT Outdoor Telecom Cabinet boasts several advantages in terms of functionality, materials, protection level, applications, and user experience. Here is a description of its advantages:

CONSNAN Outdoor Telecom Cabinet

1. Functionality: CONSNANT Outdoor Telecom Cabinets are specifically designed to house and protect sensitive telecommunications equipment in outdoor environments. They provide a secure and controlled environment for equipment such as servers, switches, power supplies, and batteries, allowing for reliable and uninterrupted operation.

2. Materials: These cabinets are constructed using high-quality materials that are capable of withstanding harsh outdoor conditions. They are usually made of rugged and durable materials such as stainless steel, aluminum, or composite materials. These materials provide excellent resistance to corrosion, rust, extreme temperatures, and UV radiation.

3. Protection level: CONSNANT Outdoor Telecom Cabinets are built to provide a high degree of protection for the equipment housed inside. They typically have a high IP (Ingress Protection) rating, such as IP65 or IP66, which means they are effectively sealed against dust, water, and other environmental factors. This level of protection ensures the equipment remains safe and operable even in challenging weather conditions.

4. Security: These cabinets are equipped with robust locking mechanisms and security features to prevent unauthorized access and vandalism. They often include tamper-proof locks, alarm systems, and CCTV surveillance capabilities. This enhances the overall security of the telecom equipment and prevents unauthorized tampering or theft.

5. Thermal Management: CONSNANT Outdoor Telecom Cabinets are engineered with efficient thermal management systems to regulate the temperature inside the cabinet. They may feature cooling fans, heat exchangers, or air conditioning systems to dissipate heat generated by the equipment. This ensures optimal operating conditions and prevents overheating, which can lead to equipment failure.

6.Applications: CONSNANT Outdoor Telecom Cabinets find applications across a range of industries and settings, including telecommunication networks, industrial facilities, transportation infrastructure, remote sites, and outdoor events. They are essential for establishing reliable and secure communication networks in these diverse environments.

7. User Experience: CONSNANT Outdoor Telecom Cabinets are designed to provide a positive user experience. They often feature ergonomic designs, user-friendly interfaces, and easy equipment access for maintenance and servicing. Additionally, these cabinets may include remote monitoring capabilities, allowing operators to monitor equipment status and performance in real-time from a central location.

Overall, CONSNANT Outdoor Telecom Cabinets offer functional, durable, and secure solutions for housing telecom equipment in outdoor environments. They provide protection against environmental elements, ensure optimal equipment performance, and enhance the user experience through robust security measures and convenient maintenance features.

Battery C Rating Explanation And Calculation

What Is Battery C Rating?

The battery C rating can be defined as the measure at which a battery is discharged relative to the maximum capacity of the batteries.

A battery’s charge and discharge rates are controlled by battery C rating. In other terms, it is the governing measure of at what current the intended batteries is charged or discharged and how quickly that occurs.

The capacity of a battery is generally rated and labeled at 3C rate(3C current), this means a fully charged battery with a capacity of 100Ah should be able to provide 3*100Amps current for one third hours, That same 100Ah battery being discharged at a C-rate of 1C will provide 100Amps for one hours, and if discharged at 0.5C rate it provide 50Amps for 2 hours.

The C rate is very important to know as with the majority of batteries the available stored energy depends on the speed of the charge and discharge currents.

Why The C Rating Are Different Between Different Battery?

1C means 1 hour discharge time.

2C means 1/2 hour discharge time.

0.5C means 2 hour discharge time.

In many applications, the battery rate is very important. For example, we want the car to be fully charged within half an hour, instead of waiting for 2 hours, or even 8 hours. What is cause influence to the battery C rating?

There are two limitations to how fast a battery can be charged-thermal heating and mass transfer limitations.

Thermal heating occurs because the internal resistance of the battery generates excessive heat, which must be dissipated to the environment.

When charging occurs at very high currents, the heat generated within the battery cannot be removed fast enough, and the temperature quickly rises.

Mass transfer of Li+ ions during fast charge results in diffusion limiting current even if the electrodes are made of nanoparticles with high surface area. While the high surface area allows sufficient rate of lithiation or de-lithiantion, the Li+ diffusion through the cross-sectional area of the electrolyte within the separator is limited. It is quite possible to fast- charge for a limited time restricted to the Li-ions already presented in the electrolyte withing the electrode. This unssteady state diffusion can last until the Li+ ions are depleted and their supply is limited by the cross-sectional area of the battery.

This mass transfer limitation occurs because the transference number of Li+ is smaller than 1. While Li+ions carry a fraction of the current in the electrolyte, they carry 100% of the current at the electrode; thus depletion of Li+ occurs near the anode, resulting in diffusion limiting current. Any attempt to surpass the limiting current results in solvent decomposition, heating and deterioration of the battery.

So different material battery will have different rate, the typical NCM lithium battery C rating is 1C, and maxium C rate can reach 10C about 18650 battery. the typical LiFePO4 lithium battery C rating is 1C, and the maxium C rate can reach 3C about LiFePO4 prismatic battery.

Battery C Rating Chart

Below chart shows the different battery C rating and their discharge time.When we caculate them, the battery C rating should use same caculation as the same energy.

Battery C Rating Chart

For most of lithium battery, here is the picture to show the discharge curve in different C rate.

Battery Discharge Curve In Different Battery C Rating

For most lead-acid batteries, we should know that even for the same battery, the battery capacity at different battery C rating is different. To get a reasonably good capacity reading, lead acid batteries manufacturers typically rate lead-acid batteries at 20 hours(A very low 0.05C).

How To Calculate The C Rating For The Battery?

A battery’s C rating is defined by the time of charge and discharge.

C-rate is an important information or data for any battery, if a rechargeable battery can be discharged at that C rating, a 100Ah battery will provide about 100A, then the battery has a discharge rate of 1C. If the battery can only provide a maximum discharge current of about 50A, then the discharge rate of the battery is 50A/100Ah=0.5C.

C-rate (C) = charge or discharge current in amperes (A) / rated capacity of the battery(Ah)

Therefore, calculating the C rating is important for any battery user and can be used to derive output current, power and energy by:

Cr = I/Er

Er = Rated energy stored in Ah

I = Charge/discharge current in A

Cr = C rate of the battery

t = Charge/discharge duration

Calculate charge and discharge time

t = Er / I

100Ah Lithium Battery C Rate Example

For same 100Ah lithium battery,

1C means 100Ah*1C=100A discharge current available.

1C means 100Ah/100A=1 hours discharge time Capable.

It means the battery can be use for 60minute (1h) with load current of 100A.

2C means 100Ah*2C=200A discharge current available.

2C means 200Ah/100A=0.5 hours discharge time Capable.

It means the battery can be use for 30minute (0.5h) with load current of 200A.

0.5C means 100Ah*0.5C=50A discharge current available.

0.5C means 100Ah/50A=2 hours discharge time Capable.

It means the battery can be use for 120minute (2h) with load current of 50A.

Sometimes analyzer capacity readings are given as a percentage of the nominal rating. For example, if a 1000mAh battery can supply this current for about 60 minutes, read 100%. However, if the battery lasts only half an hour before the cut-off point, the displayed value is 50%. Sometimes a brand new battery can provide more than 100% capacity. The battery can be discharged using an analyzer which allows you to set your favorite C rate. If the battery is discharged at a lower discharge rate it will show a higher reading and vice versa. However, you should be aware of differences in battery analyzer capacity readings for different C rates, which are related to the internal resistance of the battery.

What Are The Effects Of C Rating On Lithium-ion Batteries?

After we caculated above, we know more higher the C rating on a battery, the faster the energy can escape the batteries to power the application. The C rating on any battery depends on its application. Because some electronics require large amounts of power supply thus need batteries with high C ratings, For example, the motorcycle starter, you only needs needs a few seconds to power the motors quickly. But for some application, the discharge time only need need low C rating, Such as the soalr light, you want them to power for whole night or several nights.

What Is The C Rating Of My Battery?

You’ll usually find the battery’s C-rate on the battery’s label and on the battery’s data sheet. Different battery chemistries sometimes show different battery C rates.

Generally speaking,

Lithium iron phosphate batteries typically have a discharge rate of 1C

NCM batteries typically have a discharge rate of 3C

Lead-acid batteries are generally rated for a very low discharge rate, typically 0.05C, or 20 hour rate.

If you cannot find the battery C rating on the label or datasheet, we recommend contacting the battery manufacturer directly.

In Conclusion

The C-rate is a unit used to identify a current value/discharge time of a lithium-ion battery under different conditions. Since you have had a clear view of what the C rating is , and what it stands for in a battery, you will need to include it in your next selection for batteries to get the best out of what you settle for.

China's first 10,000-ton PV hydrogen production project

China's first 10,000-ton-level photovoltaic hydrogen production project was put into operation, with a hydrogen production capacity of 20,000 tons/year by electrolysis of water, and zero carbon emissions in the whole process.

On June 30, my country's first 10,000-ton photovoltaic green hydrogen demonstration project - Sinopec Xinjiang Kuqa Green Demonstration Project will be put into operation to produce hydrogen.

This marks the first time that my country has realized the industrial application of large-scale photovoltaic power generation direct hydrogen production process and engineering complete set of technology, providing a replicable and scalable demonstration case for the development of domestic photovoltaic power generation hydrogen production industry.

Green hydrogen is directly produced by renewable energy such as solar energy and wind energy, and basically does not produce greenhouse gases during the production process.

The project utilizes abundant solar energy resources in Xinjiang to directly produce green hydrogen. The hydrogen production capacity of electrolyzed water is 20,000 tons/year, the hydrogen storage capacity is 210,000 standard cubic meters, and the hydrogen transmission capacity is 28,000 standard cubic meters per hour.

The green hydrogen produced will be supplied to the nearby Sinopec Tahe River Industry to completely replace the existing natural gas fossil energy hydrogen production, which can reduce carbon dioxide emissions by 485,000 tons per year.