摘要
Vanadium flow batteries(VFB)offer an ideal solution to the issue of storing massive amounts of electricity produced from intermittent renewables.However,the historical challenge of high thermal precipitation of V_(2)O_(5)from VO_(2)^(+)(~50℃for 1 day)represents a critical concern.Temperature control can alleviate the problem to a certain extent,however,at the expense of the cost of system design and operation.Herein,we report stable electrolyte chemistry at high temperature.By introducing Cr^(3+)as a stabilizer,it bridges with VO_(2)^(+)to form a Cr—O—V^(Ⅴ)structure,which reduces the electron cloud density of V.Therefore,it combines more tightly with H_(2)O and prevents its dehydration process.In addition,the dimerization process of VO_(2)^(+)is also inhibited due to the occupancy of Cr^(3+).As a result,a formed 1.5 M VO_(2)^(+)electrolyte demonstrates a high stability for over 30 days at 50℃(v.s.blank for<1 day at 50℃).Additionally,the low-temperature precipitation temperature of V^(2+)on the negative side has been reduced from 0℃of commercial electrolytes to-5℃.As a proof of concept,a VFB assembled with Nafion 115 membrane demonstrates an energy efficiency(EE)of 80%at 120 mA cm^(-2)for 1000 cycles(50℃).Most importantly,a 4 kW stack can continuously run for~1000 cycles with EE of 80%at 120 mA cm^(-2)without any heat management.Combined with high thermal stability and excellent performance,our design will certainly provide new impetus for the further commercialization of VFB batteries.
基金
financially supported by National Key R&D Program of China(2022YFB2404903)
Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0400201)
International Partnership Program of Chinese Academy of Sciences(121421KYSB20210028)
National Natural Science Foundation of China(22209179,22478379)
Liaoning Provincial Natural Science Foundation(2023-MS-010)
Science and Technology Major Project of Liaoning Province(2024JH1/11700011)
International Science and Technology Cooperation program of Liaoning(2023JH2/10700002)
Liaoning Bidding for Key Technology Project(2022JH1/10800038,2023JH1/10400065)
Liaoning Binhai Laboratory Funding(LBLA-2022-02,LBLB-2023-01)。
