磷烯包覆的高性能硅基锂离子电池负极材料

摘要

硅基锂离子负极材料在脱嵌锂离子的过程中显著的体积效应导致活性材料的粉化、固体电解质介面膜(SEI)的持续生长和电接触的丧失并最终导致电池的失效.本文报道了一种新型的磷烯(单层黑磷)包覆来提升硅基负极材料的电化学性能.微量(1％,质量分数)的磷烯包覆有效抑制了被包覆硅颗粒的体积膨胀和SEI生长等问题,并保持了其电极结构在持续充放电循环中的完整性,从而提升了其库伦效率、容量以及循环稳定性.这是首次利用磷烯包覆法来提升硅基锂离子电池负极材料电化学性能的报道,而且也展现了此工艺在其他具有显著体积效应的电池材料中具有应用前景.%Si-based anode materials in Li-ion batteries (LIBs) suffer from severe volume expansion/contraction during repetitive discharge/charge,which results in the pulverization of active materials,continuous growth of solid electrolyte interface (SEI) layers,loss of electrical conduction,and,eventually,battery failure.Herein,we present unprecedented low-content phosphorene (single-layer black phosphorus) encapsulation of silicon particles as an effective method for improving the electrochemical performance of Si-based LIB anodes.The incorporation of low phosphorene amounts (1％,mass fraction)into Si anodes effectively suppresses the detrimental effects of volume expansion and SEI growth,preserving the structural integrity of the electrode during cycling and achieving enhanced Coulombic efficiency,capacity retention,and cycling stability for Li-ion storage.Thus,the developed method can also be applied to other battery materials with high energy density exhibiting substantial volume changes.