复合型添加剂对全钒液流电池电解液影响的研究OA
Study on the effects of composite additives on the electrolyte of all-vanadium redox flow batteries
随着清洁能源在发电结构中所占比例持续提升,电网侧与发电侧亟需匹配一个合适的储能方式进行电能的储存与调配,以保障系统的稳定运行.全钒液流电池(VRFB)以其长时、安全等本征特性成为了研究的热点.其中电解液在VRFB中占比巨大,其稳定性直接决定着电池性能的好坏.本研究采用复合添加剂策略,旨在改善电解液在高温条件下的稳定性.通过正交试验设计,系统考察了MgCl2、(NH4)2SO4、MSA三种添加剂的复合配比对电解液性能的影响.以容量保持率为标准进行评判,复合添加剂的最优成分及含量为MgCl2 0.1 mol/L+(NH4)2SO4 0.2 mol/L+MSA 1.0 mol/L.电池测试结果表明,在120 mA/cm²电流密度下,含复合添加剂的电解液经25次循环后,能量效率由75%提升至79%,放电容量由0.69 Ah提升至0.76 Ah,容量保持率由83%提升至90%,分别提升5.33%、10.14%与8.43%;在230次长循环中,其能量效率仍稳定在约82%,较对照组相对提升约9.33%,放电容量与容量保持率均显著优于未添加体系.同时,50℃高温静置一周后,电解液沉淀体积由11.31 cm3降至7.72 cm3,降幅达34.39%;离子色谱(IC)结果证实,添加剂可在电解液中长期稳定存在,未发生显著跨膜迁移行为.综上,该复合添加剂可同时提升电解液的热稳定性与电池充放电性能,为全钒液流电池的高效稳定运行提供了可行的技术方案.
As the share of clean energy in the electricity generation mix continues to rise,grid-side and generation-side stakeholders must urgently deploy energy storage technologies to suitably manage power demand and ensure stable system operation.In this context,vanadium redox flow batteries(VRFBs),with advantages such as long-duration energy storage capability and intrinsic safety,have attracted significant research interest.The electrolyte is a major cost component of VRFBs,and its stability directly governs the battery electrochemical performance.This study adopts a composite additive strategy to improve electrolyte thermal stability and suppress vanadium precipitation under elevated temperatures.The effects of the composite ratios of MgCl2,(NH4)2SO4,and methanesulfonic acid(MSA)on electrolyte performance were systematically investigated using an orthogonal experimental design.Based on capacity retention rate,the optimal additive formulation was determined to be 0.1 mol/L MgCl2+0.2 mol/L(NH4)2SO4+1.0 mol/L MSA.Battery testing showed that,at 120 mA/cm2 current density,the electrolyte with the composite additive increased energy efficiency from 75%to 79%,discharge capacity from 0.69 Ah to 0.76 Ah,and capacity retention from 83%to 90%after 25 cycles,respectively corresponding to relative improvements of 5.33%,10.14%,and 8.43%.During 230 long-term cycles,the energy efficiency remained stable at 82%,representing a relative improvement of about 9.33%over the control group,while both discharge capacity and capacity retention were significantly higher than those of the additive-free system.After static storage at 50℃for one week,the electrolyte precipitate volume decreased from 11.31 cm3 to 7.72 cm3(a 34.39%reduction).Ion chromatography confirmed that the additive remained stable in the electrolyte over an extended period without significant cross-membrane migration.In summary,this composite additive improves both the electrolyte thermal stability and the battery charge-discharge performance,providing a feasible technical solution for the efficient and stable operation of all-vanadium redox flow batteries.
王熙俊;李朔;马晓涵;董靖;吴华成;范永哲;李世杰;杜安;王志华
国网冀北电力有限公司电力科学研究院(华北电力科学研究院有限责任公司),北京 100045国网冀北张家口风光储输新能源有限公司,河北 张家口 075000河北工业大学材料科学与工程学院,天津 300401国网冀北电力有限公司电力科学研究院(华北电力科学研究院有限责任公司),北京 100045国网冀北电力有限公司电力科学研究院(华北电力科学研究院有限责任公司),北京 100045河北工业大学材料科学与工程学院,天津 300401河北工业大学大学生创新创业中心,天津 300401河北工业大学材料科学与工程学院,天津 300401智能配用电装备与系统全国重点实验室(河北工业大学),天津 300401
信息技术与安全科学
全钒液流电池电解液热稳定性复合添加剂
all-vanadium redox flow batteryelectrolytethermal stabilitycomposite additives
《储能科学与技术》 2026 (8)
3018-3032,15
国网冀北电力有限公司科技项目(52018K25000Q).
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