New generation 70kW high power density all vanadium flow battery cell stack

Not long ago, the Li Xianfeng team of the Energy Storage Technology Research Department of the Chinese Academy of Sciences Dalian Institute of Chemical Physics successfully developed a new generation of 70kW high power density all vanadium liquid flow battery single stack through unremitting efforts.

The volumetric power density of the single cell stack has been increased from the current 70kW/m ³ to 130kW/m ³, and the power has been increased from 30kW to 70kW while maintaining the same volume. The cost has been reduced by 40% compared to the 30kW level stack at that time. This technological innovation has further improved the economy and reliability of all vanadium flow batteries.

Bismuth single atom loaded graphite felt electrode for high power density all vanadium flow battery

Recently, researchers Li Xianfeng and Liu Tao from the Energy Storage Technology Research Department (DNL17) of Dalian Institute of Chemical Physics have made new progress in the research of high-power density all vanadium flow battery electrodes. They have developed a bismuth (Bi) single atom loaded graphite felt electrode, which has an energy efficiency of 81.2% and a peak power density of 990mW/cm2 at a current density of 240mA/cm2, providing new ideas for the design of electrode materials for high-power density all vanadium flow batteries.

Neutralization energy storage develops non fluoride ion membrane for efficient flow batteries

Shenzhen Zhonghe Energy Storage Technology Co., Ltd. has launched a strategic cooperation with Central South University on the research and industrialization of key materials for flow batteries.

In this work, the application of polybenzimidazole (PBI) membrane in vanadium redox flow batteries (VRFB) was explored, and a scheme was proposed to improve the proton conductivity of PBI membrane through deprotonation strategy to overcome its insufficient proton conductivity in VRFB applications. The synchronous breakthrough from material research to industrialization of non fluoride ion exchange membranes has been achieved, promoting the commercial application of products and successfully solving the problem of low-cost non fluoride ion exchange membrane performance being difficult to meet industrial requirements.

It is reported that the non fluoride ion exchange membrane series products are currently in the continuous pilot production stage, with an energy efficiency of over 80% at an electric density of 200mA/cm2. Existing mature products: PBI flow battery membrane, PBI fuel cell membrane, which can be applied to fields such as flow batteries, fuel cells, hydrogen energy, metal ion separation, etc. A product with a width of 60 centimeters has been launched for sale and promoted for application.

5kW iron-based liquid flow battery stack achieves energy efficiency of over 80%

In 2024, the 5kW iron-based liquid flow battery stack project jointly developed by Sotong New Energy Technology and Professor Cheng Yuanhui's team at Beijing University of Chemical Technology has made new progress, achieving an energy efficiency of over 80%.

In June 2024, the system will be assembled and put into testing. In testing, the R&D team used industrial grade bulk raw materials and mature processes to macroscopically prepare iron-based electrolytes. After hundreds of charge and discharge cycles, the energy efficiency of the fuel cell stack was tested. The test results show that the energy efficiency of the fuel cell stack is around 80% at different output powers, reaching a practical level, indicating that the electrolyte preparation technology, fuel cell design and integration technology have achieved amplification from hundreds of watts to several kilowatts, and have opened up the key link for the industrialization of iron-based flow battery technology.

500kW/2MWh world's largest single capacity vanadium iron flow battery released

On June 7, 2024, Shanghai Electric Energy Storage launched the world's largest single capacity vanadium iron flow battery: 500kW/2MWh vanadium iron flow battery.

This flow battery is based on "system innovation and vanadium iron fusion", characterized by high performance, low cost, long lifespan, low auxiliary consumption, and wide adaptability.

It is understood that the single stack power of the flow battery is 45kW, and the single module power is 500kW. The energy efficiency of the fuel cell stack is greater than 80%, and the bypass current and thermal simulation technology improve the energy efficiency of the battery; Integrated process design effectively reduces battery internal resistance and ensures high energy efficiency; The AC efficiency of the energy storage module is greater than 75%. By using the vanadium iron electrolyte and non fluoride ion exchange membrane exclusively developed by Shanghai Electric, the cost per kilowatt hour can be reduced by 40%, thereby lowering investment costs.

Progress has been made in the research of all iron flow batteries with a 10 fold increase in cycle stability

In 2024, the team led by Li Ying and Tang Xuan, researchers of the Institute of Metals, Chinese Academy of Sciences, made new progress in the research field of new low-cost iron based flow battery energy storage technology.

In order to break the limitation of poor reversibility of iron negative electrode electrochemical reactions in all iron flow batteries, researchers conducted metal etching treatment at the electrode interface to enrich the surface of electrode fibers with defect structures, effectively regulating the deposition reaction nucleation characteristics of iron ions at the electrode interface, promoting the uniformity of iron deposition reaction and redox reaction kinetics. Theoretical calculations and simulation analysis were used to reveal the mechanism of enhanced hybridization of iron ions at carbon defects and the evolution law of iron deposition process.

The all iron flow battery assembled on this basis achieved a power density of 80 milliwatts per square centimeter and a current efficiency of 99% after 250 cycles. The cycle stability was effectively improved by 10 times, and for the first time, the entire battery was able to operate stably for 100 hours under low temperature conditions of -20 ℃. The research results demonstrate that optimized electrode interface design can effectively improve the performance of iron negative electrodes, providing a new approach for achieving efficient and stable operation of all iron flow batteries.

Significant progress has been made in aqueous organic flow batteries

The successful transformation of neutral aqueous organic flow batteries (AORFBs) from laboratory innovation to large-scale manufacturing largely relies on the development of high-performance electrolyte materials. Naphthalimide materials have attracted much attention due to their unique planar rigid structure and excellent dual electron storage properties. However, naphthalimide derivatives as negative electrode electrolyte materials still face two major challenges: insufficient high concentration performance and high preparation costs.

Sulfur based flow batteries usher in new breakthroughs

On July 29, 2024, the first national demonstration project for charging station distribution and storage using sulfur based flow battery energy storage system was officially launched and connected to the grid in Bao'an. This is also the first sulfur based flow battery energy storage system used for demonstration projects. The project is jointly carried out by Hong Kong China Gas subsidiary, Ganghua Smart Energy, and Luquos Energy. The successful grid connection of the project marks the successful completion of the pilot scale technical verification of sulfur based liquid flow battery technology and the entry into the fast track of industrialization.