钠离子电池筛分型碳:缘起与进展

Sieving carbons for sodium-ion batteries:Origin and progress

钠离子电池被广泛认为是锂离子电池在大规模储能应用领域的最佳补充甚至替代,硬碳是目前最具潜力的实用化负极材料,但硬碳负极低电位平台的产生机制仍存争议,且硬碳复杂的微纳结构与低电位平台的关联机制尚不明确,严重制约了钠离子电池的产业化进程。本工作首先概述了钠离子电池碳负极的研究进展与关键挑战,并分析探讨了设计理想碳负极的关键结构要素;其次介绍了本研究团队有关碳分子筛负极的研究进展,并基于碳分子筛提出了理想的碳负极模型——筛分型碳;最后重点论述了筛分型碳“樱桃小嘴、大腹便便”的孔结构特征及其对储钠机制和电化学性能的影响,明确提出了筛分型碳负极的理性设计原则,并对筛分型碳未来在钠离子电池产业化进程中所面临的机遇和挑战进行了简要的评述和探讨。

Sodium-ion batteries(SIBs)are widely recognized as the best supplement to lithium-ion batteries in the field of large-scale energy storage applications.Hard carbons are the most practical anode materials for SIBs.However,the controversial sodium storage mechanism associated with the low-potential plateau and unknown structure-performance relationship of hard carbon anodes severely limits the commercialization of SIBs.This study summarizes the research progress and key challenges of different carbon anodes in SIBs and introduces the critical structural features of designing the ideal carbon anode.Then,inspired by our previous work on commercial carbon molecular sieves,we propose the ideal carbon model called"sieving carbons"The unique pore structure of sieving carbons,which we describe as a small pore mouth with a large pore stomach,and its impact on the sodium storage mechanism and properties are discussed in detail.Finally,the rational design principles for sieving carbon anodes with reversible and extensible low-voltage plateaus are discussed,as well as the opportunity and challenge of sieving carbons in promoting the commercialization of SIBs.