How a very trace amount of graphene additive works for constructing an efficient conductive network in LiCoO₂-based lithium-ion batteries

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• 作者：Rui Tang^a ; ^b ; Qinbai Yun^a ; ^b ; Wei Lv^a ; Yan-Bing He^a ; ^{he.yanbing@sz.tsinghua.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Conghui You^a ; Fangyuan Su^a ; ^c ; Lei Ke^a ; ^b ; Baohua Li^a ; Feiyu Kang^a ; ^b ; Quan-Hong Yang^a ; ^d ; ^{yang.quanhong@sz.tsinghua.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; ^{qhyangcn@tju.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 刊名：Carbon
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：103
• 期：Complete
• 页码：356-362
• 全文大小：1311 K

文摘

This work demonstrates how a very low fraction of graphene greatly enhances the usage efficiency of carbon-based conductive additive in LiCoO₂-based lithium ion batteries (LIB) and develops a strategy using binary conductive additive to have a high performance battery, especially with excellent rate performance. With a much lower fraction of carbon additive for a commercial LIB, only 0.2 wt% graphene nanosheet (GN) together with 1 wt% Super-P (SP) constructing an effective conductive network, the prepared battery exhibits outstanding cycling stability (146 mAhg⁻¹ at 1C with retention of 96.4% after 50 cycles) and rate capability (116.5 mAhg⁻¹ even at 5C). In this battery, a composite conducting network is formed with a long-range electron pathway formed by a trace amount of GN and the short-range electron pathway by aggregation of SP particles. More interestingly, in micro-sized LiCoO₂ system, the GN additive does not present hindrance effect for lithium ion transport even in high rate discharge, which is entirely different from the nano-sized LiFePO₄ system. This study further demonstrates commercial potential of GN additive for high performance LIB and more importantly gives a well-designed recipe for its real application.