原位氟化凝胶电解质构筑界面稳定的高压锂电池

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中图分类号：TQ050.4 文献标志码：A

Abstract：Underhigh-voltageoperation，thesolventsandanionsintraditionalgelpolymerelectrolytes（GPEs）areproetoir reversibleoxidativedecomposition，leadingtotheformationofheterogeneoushigh-impedancecathodeelectrolyteinterphase （CEI）filmandthedisolutionof transitionmetals.Meanwhile，theliquidcomponentsintheelectrolytereactviolentlywiththe lithiummetal toformafragilesolidelectrolyteinterphase（SEI）film.Thisexacerbatestheunevenionflux，dendritegrowth， andaccumulationof"deadlithium"，significantlyincreasingtheriskofshort-circuitingandaceleratingcapacityfade.Terefore，acompositegel electrolytewasdevelopedthroughmoleculardesignandinterfacialsynergisticregulationstrategies，using in-situcopolymerizationofpolyethyleneglcoldiacrylate（PEGDA）and2，2，2-trifluoroethylacrylate（TEA）astheframwork，and succinonitrile（SN）as an additive.The results show that the -CF3 groups in TFEA are preferentially reduced to formaLiFrichSEIlayer，whichhas highionicselectivitytohomogenizethelithium-ionflux，inhibitdendriteformation，and achievestablecyclingoflithiumsymmetriccellsforover13Oh.Onthecathodeside，thehighvoltageoxidativedecomposition of SN generates highly ionic Li3N ，which synergistically constructs a stable CEI layer with the LiF component formed by the oxidativedecompositionofTFEA，jointlysuppressng thedecompositionofsolvents/lithiumsaltsandthedisolutionof transitionmetals.The electrochemical stability window of theelectrolyte is significantly extended to 4.8V ，and the assembled Lill LiNi0.8Co0.1Mn0.1O2 cell achieves a high capacity retention of 75.23% （at 0.5C）after 120 cycles at 4.5V ：

Keywords：lithium-ion battery；gel electrolyte；interface；high-voltage

锂电池泄漏和漏电在内的安全问题严重阻碍了其进一步发展[1-3]。（剩余13574字）