Multifunctional Conductive Skin Strategy for High-Performance Lithium-Ion Battery Electrode Materials

Abstract

Rapidly growing smart energy era, which includes flexible/wearable electronics, electric vehicles, and stationary electricity storage systems, is in relentless pursuit of high-performance lithium-ion rechargeable batteries with reliable/sustainable electrochemical properties as a promising power source. Development of the advanced lithium ion-batteries, however, is staggering with thorny problems of performance decay with cycling and safety failures, which are highly concerned with electrochemical/thermal instability at electrode material-liquid electrolyte interface. Notably, these interfacial issues are more pronounced at harsh operating conditions such as high-voltage and high-temperature. Here, as a new concept of surface engineering to address the longstanding interfacial issues, we demonstrate multifunctional conductive skin layers based on ion-conductive polymers and electron-conductive carbonaceous materials. In comparison to conventional inorganic coating approaches, the new coating layer proposed herein, as a kind of artificial skin, can provide conformal surface coverage over a wide area of electrode active materials. The structural characteristics and chemical functionality of the skin layers are extensively elucidated, with a focus on interfacial phenomena between electrode active materials and liquid electrolytes. The skin layers, driven by their well-tailored morphology and multifunctionality, enable significant improvement in electrochemical performance and thermal stability of lithium-ion batteries.