Few Atomic Layered Lithium Cathode Materials to Achieve Ultrahigh Rate Capability in Lithium-Ion Batteries.

Abstract

The most promising cathode materials, including LiCoO2 (layered), LiMn2 O4 (spinel), and LiFePO4 (olivine), have been the focus of intense research to develop rechargeable lithium-ion batteries (LIBs) for portable electronic devices. Sluggish lithium diffusion, however, and unsatisfactory long-term cycling performance still limit the development of present LIBs for several applications, such as plug-in/hybrid electric vehicles. Motivated by the success of graphene and novel 2D materials with unique physical and chemical properties, herein, a simple shear-assisted mechanical exfoliation method to synthesize few-layered nanosheets of LiCoO2 , LiMn2 O4 , and LiFePO4 is used. Importantly, these as-prepared nanosheets with preferred orientations and optimized stable structures exhibit excellent C-rate capability and long-term cycling performance with much reduced volume expansion during cycling. In particular, the zero-strain insertion phenomenon could be achieved in 2-3 such layers of LiCoO2 electrode materials, which could open up a new way to the further development of next-generation long-life and high-rate batteries.