In situ fabrication of dual coating structured SiO/1D-C/a-C composite as high-performance lithium ion battery anode by fluidized bed chemical vapor deposition
In situ fabrication of dual coating structured SiO/1D-C/a-C composite as high-performance lithium ion battery anode by fluidized bed chemical vapor deposition
复制标题
流化床化学气相沉积原位制备双涂层结构SiO/1D-C/a-C复合材料作为高性能锂离子电池负极
DOI：
10.1016/j.carbon.2020.06.053
复制
发表时间：
2020
期刊：
影响因子：
10.9
通讯作者：
Qingshan Zhu
中科院分区：
文献类型：
--
作者：
Hebang Shi;He Zhang;Xinxin Li;Yu Du;Guolin Hou;Maoqiao Xiang;Pengpeng Lv;Qingshan Zhu
为了显著提高高容量SiO阳极的循环稳定性，利用一维碳（1D-C）的高导电性和非晶碳（a-C）的优良缓冲性，提出了一种新颖的碳双涂层结构。探讨了通过调节工艺温度来控制碳沉积的规律。推导出1D-C和a-C之间碳沉积的演化机制，即低温催化生长和高温热解沉积之间的竞争模式。基于碳沉积机理，提出了流化床化学气相沉积两步法制备SiO/1D-C/a-C复合材料的新工艺。生长的增厚的1D-C和沉积的a-C不均匀地包覆在SiO颗粒表面，形成巧妙的双包覆结构。合成的SiO/1D-C/a-C显示出极其显著的增强的循环稳定性，其在120次循环后显示出1012 mAh g-1的可逆容量（容量保持率为88.3%）。增厚的1D-C相互缠绕形成三维导电网络，而沉积的a-C形成壳状涂层以缓冲循环期间的体积膨胀。独特的碳双涂层结构实现了协同强化，保证了SiO/1D-C/a-C上级的电化学性能。
To notably improve the cycling stability of high-capacity SiO anode, an ingenious carbon dual coating structure was proposed, utilizing the high conductivity of 1D carbon (1D-C) and the excellent buffering of amorphous carbon (a-C). The carbon deposition pattern by regulating process temperatures was explored. An evolutive carbon deposition mechanism between 1D-C and a-C was deduced, which was a competitive mode between low-temperature catalytic growth and high-temperature pyrolysis deposition. Motivated by the deduced carbon deposition mechanism, a novel two-step coating process via fluidized bed chemical vapor deposition was proposed to fabricate the SiO/1D-C/a-C composite. The grown thickened 1D-C and deposited a-C were heterogeneously coated on the SiO particle surface, forming an ingenious dual coating structure. The synthesized SiO/1D-C/a-C exhibited extremely significant enhanced cycling stability, which showed a reversible capacity of 1012 mAh g−1(capacity retention of 88.3%) after 120 cycles. The thickened 1D-C is entangled with each other to form a three-dimensional conductive network, while the deposited a-C formed a shell-like coating to buffer the volume expansion during cycling. The unique carbon dual coating structure achieved synergistic strengthening, which guarantees the superior electrochemical performance of the SiO/1D-C/a-C.