Unraveling the ethylene carbonate effect on the electro-chemical/thermosafety features for practical LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)||graphite pouch cells  

揭示碳酸乙烯酯对LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)||石墨软包电池的电化学/热安全特性的影响

作　　者：Zhihao Liu Xin Wen Yingchen Xie Fengfei Wang Li Wang Yu Wu Xuning Feng 刘志浩;温昕;谢颖晨;王凤飞;王莉;吴宇;冯旭宁(School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China;National Key Laboratory of Science and Technology on Materials under Shock and Impact,Beijing Institute of Technology,Beijing 100081,China;China North Standardization Center,Beijing 100089,China;State Key Laboratory of Intelligent Green Vehicle and Mobility,Tsinghua University,Beijing 100084,China;Rocket Force University of Engineering,Xi’an 710025,China;Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China)

机构地区：[1]School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China [2]National Key Laboratory of Science and Technology on Materials under Shock and Impact,Beijing Institute of Technology,Beijing 100081,China [3]China North Standardization Center,Beijing 100089,China [4]State Key Laboratory of Intelligent Green Vehicle and Mobility,Tsinghua University,Beijing 100084,China [5]Rocket Force University of Engineering,Xi’an 710025,China [6]Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China

出　　处：《Science China Materials》2024年第10期3236-3244,共9页中国科学（材料科学）（英文版）

基　　金：supported by the National Key R&D Program-Strategic Scientific and Technological Innovation Cooperation(2022YFE0207900);the National Natural Science Foundation of China(52004138 and 52076121);the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact(WDZC2022-2);the Beijing Institute of Technology Research Fund Program for Young Scholars(XSQD-202210008)。

摘　　要：With the continuous development of the electrification industry,the development of high-specific batteries has attracted much attention.However,the safety of lithiumion batteries is currently unable to meet the market demand due to poor thermal stability.Solving the thermal issues is crucial to improve battery safety.Ethylene carbonate(EC)not only plays an important interfacial film-forming role,but also poses safety risks in terms of reactivity.In this work,we conducted a series of gradient experiments utilizing different EC amounts and verified the effect of reducing EC on battery performance.A strategy is also proposed to design a new electrolyte.Ethyl methyl carbonate(EMC)is used instead of EC as the main solvent to improve the thermal safety of the battery,while salts and additives are used to dominate the film formation to improve the cycling stability of the battery under high voltages(4.5 V,~90%after 200 cycles).This work paves a new avenue for the development of novel electrolyte systems.电动化产业的不断发展,使得高性能电池的开发备受关注.然而,由于锂离子电池自身热稳定性差,目前其安全性还无法满足市场需求.解决热安全问题是提高电池安全性的关键.碳酸乙烯酯(EC)具有重要的界面成膜功能,但也存在反应性方面的安全风险.在这项工作中,我们设计了不同含量的EC,进行了一系列梯度实验,展示了减少EC量对电池性能的影响.本文同时提出一种设计新型电解质的策略:使用EMC代替EC作为主溶剂,以提高电池的热安全性;使用盐和添加剂主导成膜,以提高电池在高电压下的循环稳定性(4.5 V,200次循环后≈90%).本工作为新型电解液系统的开发提供了新的思路.

关 键 词：lithium-ion batteries safety ethylene carbonate high voltage ELECTROLYTE 

分 类 号：TM912[电气工程—电力电子与电力传动] O646[理学—物理化学]