Lin Qiaowei, Zhang Jun, Lv Wei, Ma Jiabin, He Yanbing, Kang Feiyu, Yang Quan-Hong
Shenzhen Geim Graphene Center, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China.
Small. 2020 Apr;16(15):e1902603. doi: 10.1002/smll.201902603. Epub 2019 Aug 6.
Sodium-ion batteries (SIBs) are promising for large-scale energy storage systems and carbon materials are the most likely candidates for their electrodes. The existence of defects in carbon materials is crucial for increasing the sodium storage ability. However, both the reversible capacity and efficiency need to be further improved. Functionalization is a direct and feasible approach to address this issue. Based on the structural changes in carbon materials produced by surface functionalization, three basic categories are defined: heteroatom doping, grafting of functional groups, and the shielding of defects. Heteroatom doping can improve the electrochemical reactivity, and the grafting of functional groups can promote both the diffusion-controlled bulk process and surface-confined capacitive process. The shielding of defects can further increase the efficiency and cyclic stability without sacrificing reversible capacity. In this Review, recent progresses in the ways to produce surface functionalization are presented and the related impact on the physical and chemical properties of carbon materials is discussed. Moreover, the critical issues, challenges, and possibilities for future research are summarized.
钠离子电池（SIBs）在大规模储能系统方面颇具前景，而碳材料是其电极最有可能的候选材料。碳材料中缺陷的存在对于提高储钠能力至关重要。然而，其可逆容量和效率都有待进一步提高。功能化是解决这一问题的直接且可行的方法。基于表面功能化导致的碳材料结构变化，定义了三个基本类别：杂原子掺杂、官能团接枝以及缺陷屏蔽。杂原子掺杂可提高电化学反应活性，官能团接枝既能促进扩散控制的体相过程，又能促进表面受限的电容过程。缺陷屏蔽可在不牺牲可逆容量的情况下进一步提高效率和循环稳定性。在本综述中，介绍了产生表面功能化方法的最新进展，并讨论了其对碳材料物理和化学性质的相关影响。此外，总结了未来研究的关键问题、挑战和可能性。
