Tunable porous carbon spheres for high-performance rechargeable batteries

Abstract

Carbon-based materials have been widely applied as anode materials in commercial lithium ion batteries due to their low cost, excellent stability and relatively good energy storage capability. However, the maximum theoretical specific capacity of graphite is unsatisfactory (372 mA h g⁻¹), which cannot meet the high-energy-density requirements for advanced electric vehicles. Porous carbon spheres (PCSs) are one of the most promising electrode materials for high-performance batteries because of their tunable porous structure and high compatibility with other materials. Specifically, PCSs can provide effective paths and space to transfer electrons/ions in electrodes, resulting in high-performance rechargeable batteries. The use of carbon spheres can also overcome the issues of unwanted side reactions to increase coulombic efficiency (CE) and bring potential for tuning the surface characteristics to attain high capacity. The porous carbon spheres with controllable structures are able to enhance the electrochemical performances of electrodes due to their multifunctional effects in different types of rechargeable batteries. This review focuses on tunable pore structure design, surface chemistry, composition, and electrochemical performances of PCSs in various types of rechargeable batteries. This paper aims to provide an overview for understanding the development of porous carbon spheres and strategies to overcome obstacles, such as low specific capacity, unsatisfactory CE, low tap density and inferior rate performance for their use in rechargeable batteries. Prospects and challenges for porous carbon spheres in rechargeable batteries are discussed to provide insight and inspiration for promoting the development of next-generation high-performance batteries.