Bridging porous Si-C composites with conducting agents for improving battery cycle life
Bridging porous Si-C composites with conducting agents for improving battery cycle life
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DOI：
10.1016/j.jpowsour.2015.04.036
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发表时间：
2015-07-15
影响因子：
9.2
通讯作者：
Liu, Zhaoping
中科院分区：
文献类型：
--
作者：
Li, Zhenzhen;Wang, Wei;Liu, Zhaoping
多孔硅-碳（Si-C）复合材料因其在充放电过程中能适应较大的体积变化而被认为是提高硅基负极循环寿命的最有效结构之一。研究发现，大量报道的多孔Si-C电极采用大量的粘结剂材料来提高结构稳定性，但在活性物质含量有限的情况下，电极整体的重量容量显著降低。在这项工作中，在不损失活性物质的情况下，使用各种导电剂在多孔Si-C复合材料之间建立电桥，这显著提高了结构稳定性，从而提高了循环寿命。由于连接可能性的增加，零维MCMB桥接电极的循环寿命达到80次循环，容量保持率为80%，并且对于VGCF桥接电极可以进一步提升到200次循环，对于rGO桥接电极可以进一步提升到220次循环。该工作为在不减少活性物质的前提下，以多孔结构为构筑块构建稳定的硅电极提供了一条有效途径。(C)2015 Elsevier B. V.版权所有。
Porous silicon-carbon (Si-C) composites have been considered to be one of the most effective architectures to improve the cycle life of Si based anode because of its native ability to accommodate the large volume change during discharge/charge process. It is found that lots of reported porous Si-C electrodes employed large amount of binder materials to enhance the structural stability which significantly decreased gravimetric capacity of the whole electrode with limited active materials. In this work, without loss of active materials, various conducting agents were used to build electrical bridges between porous Si-C composites, which significantly improved the structural stability and hence the cycle life. Due to the increase of connection possibilities, cycle life of zero-dimensional MCMB bridged electrode reaches 80 cycles with a capacity retention of 80%, and it can be further promoted to 200 cycles for the VGCF bridged electrode and 220 cycles for the rGO bridged electrode. This work paves an effective route to construct stable Si electrode with porous structures as building blocks without the decrease of active materials. (C) 2015 Elsevier B.V. All rights reserved.