固态锂电池研究及产业化进展

Research and industrialization progress of solid-state lithium battery

相比于传统液态锂离子电池,固态锂电池(SSLB)用固态电解质代替有机电解液,安全性和能量密度均大大提升,可以有效降低电动汽车安全隐患和缓解用户续航里程焦虑。固态电解质作为电子绝缘体和离子导体是SSLB核心要素之一,同时其存在离子电导率低、界面阻抗大和界面稳定性差等问题。通过研究近期相关文献,对硫化物固态电解质、氧化物固态电解质、聚合物固态电解质以及复合固态电解质锂电池的离子导电机理、研究进展、存在的主要问题及解决方案进行了综述和讨论。对于提高离子电导率,重点介绍了调整固态电解质组分的方法。对于改善界面问题,主要介绍了界面设计和制成工艺方法改善思路。综合分析表明,通过掺杂和包覆改性固态电解质、探索先进界面研究和诊断技术并指导设计具有优良锂离子传输能力的界面、创新和优化工艺能有效地提升固态电解质综合性能。最后列举了国内外重点企业的固态锂电池产业化进程,对固态锂电池未来应用前景进行了分析和展望。

Compared with the traditional liquid lithium-ion battery,a solid-state lithium battery(SSLB)uses a solid electrolyte instead of an organic electrolyte to greatly improve safety and energy density,which can effectively reduce safety risks of electric vehicles and relieve users'anxiety.A solid electrolyte is one of the core elements of SSLB and serves as the electronic insulator and ionic conductor.However,several problems,such as the low ionic conductivity,large interface impedance,and poor interface stability,exist with the use of this electrolyte.Based on the discussion of relevant literatures,the ionic conduction mechanism,and the research progress of sulfide solid electrolyte,oxide solid electrolyte,polymer solid electrolyte,and composite solid-electrolyte SSLB,the main problems and solutions of these four solid electrolytes were mainly reviewed and discussed in this work.For the improvement of ionic conductivity,the methods for adjusting the composition of solid electrolytes were introduced.As for the improvement of the interface,this work introduced the idea of interface design and manufacturing process.The comprehensive analysis showed that the performance of solid electrolytes can be effectively improved through doping and coating modification,exploration of the advanced interface research and diagnosis technology,and guidance of interface design with an excellent lithium-ion transport capacity,and innovation and optimization of the process.Finally,the industrialization processes of solid-state lithium batteries in domestic and foreign key enterprises were listed,and the future application prospect of solid-state lithium batteries was analyzed and prospected.