Dual or multi carbonaceous coating strategies for next-generation batteries

Lithium-ion batteries (LIBs) have become energy storage tools in our daily lives, and high energy and power densities as well as long lifespan are necessary for next-generation batteries for transportation technologies and smart grids. Newly emerging electrode materials fabricated with rational component design are coming close to achieving this feat, but essential drawbacks such as insufficient electron/ion-transport efficiency, large volume variations and various side reactions hinder their practical applications. Although carbon coating has long been considered an effective method to improve the electrochemical performance by increasing conductivity, buffering volume expansion and/or stabilizing the reaction interface, it has been proven that a single species of carbon is unable to meet all requirements in terms of conformal coverage for active materials and a continuous conductive network for electrodes. In this review, we mainly focus on recent developments in dual or multi carbonaceous coating strategies, aiming to summarize the hierarchical construction of complex structures and consequently discuss the multifunctionality of each carbonaceous material for the rational design of electrodes not only for LIBs but also for other rechargeable batteries to be developed in the future.