Designing a slope-dominated hybrid nanostructure hard carbon anode for high-safety and high-capacity Na-ion batteries
Designing a slope-dominated hybrid nanostructure hard carbon anode for high-safety and high-capacity Na-ion batteries
复制标题
设计用于高安全性和高容量钠离子电池的斜率主导的混合纳米结构硬碳负极
DOI：
10.1039/d0ta08895a
复制
发表时间：
2020-11-21
影响因子：
11.9
通讯作者：
Jiang, Kai
中科院分区：
文献类型：
--
作者：
Jin, Qianzheng;Wang, Kangli;Jiang, Kai
虽然硬碳负极钠离子电池已经实现了高容量和稳定循环，但关键的安全问题，低放电电位和不令人满意的倍率性能，为其实际应用提出了巨大的挑战。在此，斜率主导的机制策略已被设计通过使用CVD类方法制备杂化纳米结构碳材料（HNC），提供具有优异的倍率性能和高平均放电电势的硬碳作为钠离子电池的阳极。HNC集碳纳米管和碳纳米片的优点于一身，离子/电子传递距离短，比表面积大，活性中心丰富。此外，它们的微观结构特性，包括无序度和杂原子硫的存在状态，可以通过不同的合成温度进行调节，提供有效的纳米空隙和键合位点。基于反应动力学分析，可以确定HNC的Na离子存储机制为电容控制过程，这对于提高倍率性能至关重要。本工作展示了一种开发混合纳米结构硬碳的新方法，以及用于高性能和高安全性钠离子电池的电化学存储机制的设计。
Though high capacity and stable cycling of hard carbon anode Na-ion batteries have been achieved, critical safety issues, low discharge potential and unsatisfactory rate performance, present a huge challenge for their practical application. Herein, a slope-dominated mechanism strategy has been designed by preparing hybrid nanostructure carbon materials (HNCs) using a CVD-like method, providing hard carbon with excellent rate performances and high average discharge potential as an anode for Na-ion batteries. The HNCs integrate the advantages of carbon nanotubes and carbon nanosheets, presenting short ion/electron transfer distance and high surface area for abundant active sites. In addition, their microstructural properties including disorder degree and existing state of heteroatom sulfur, can be regulated via different synthetic temperatures providing effective nanovoids and bonding sites. Based on the reaction kinetics analysis, the Na-ion storage mechanism of HNCs can be determined as a capacitive-controlled process, which is essential for improving rate performances. This work demonstrates a novel method to develop a hybrid nanostructure hard carbon, and design of an electrochemical storage mechanism for high-performance and high-safety Na-ion batteries.