锂/钠离子电池硬碳负极材料的研究进展

Research Progress on Hard Carbon Anode for Li/Na-ion Batteries

随着锂离子电池的发展和钠离子电池的兴起,硬碳材料作为一种新型负极材料,受到了广泛关注。硬碳来源丰富,价格便宜,具有比锂离子电池石墨负极更高的储锂容量和优异的倍率性能,并且是最有商业化潜质的钠离子电池负极材料。然而,硬碳普遍存在电池首周库仑效率低的问题,且对于硬碳的储锂/钠机制仍存在争论,其比容量仍有较大的提升空间。近年来,研究人员围绕硬碳负极材料的电化学机理展开了各种研究和模型假设,针对硬碳负极存在的问题,提出了各种解决策略。本文介绍了硬碳的基本结构和常用的制备方法,并结合硬碳的优势,梳理了硬碳在锂离子电池和钠离子电池中的应用情况,重点介绍了其在快充、包覆等细分领域的应用进展,并分别针对硬碳提升比容量和改善首周库仑效率的需求,归纳了孔结构设计、元素掺杂、优化材料与电解液界面等不同改性策略。

With rapid development of lithium ion batteries(LIB)and sodium ion batteries(SIB),hard carbon(HC)as new anode material has earned much attention.Besides its rich precursor sources and low cost,HC has higher Li+storage capacity and better rate performance than graphite for LIB.Furthermore,it is also recognized as the most commercially potential anode material for SIB.However,low initial Coulombic efficiency is a common issue for HC.In addition,it is believed that the specific capacity can be further improved with the clarification of the Li/Na ion storage mechanism.In recent years,many researches on electrochemical mechanism have been conducted with some model assumptions proposed for better understanding the mechanism.This review introduced the structures and preparation approaches of HC as well as its application in LIB and SIB.The advantages,especially in fast charging,coating and other subdivision were discussed,and the different modification strategies such as pore structure design,doping,optimizing interface between electrode and electrolyte were summarized,aiming at the increase of capacity and the improvement of Coulombic efficiency of batteries.