A Graphene-Pure-Sulfur Sandwich Structure for Ultrafast, Long-Life Lithium-Sulfur Batteries
A Graphene-Pure-Sulfur Sandwich Structure for Ultrafast, Long-Life Lithium-Sulfur Batteries
复制标题
用于超快、长寿命锂硫电池的石墨烯-纯硫三明治结构
DOI：
10.1002/adma.201302877
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发表时间：
2014-01-01
影响因子：
29.4
通讯作者：
Cheng, Hui-Ming
中科院分区：
文献类型：
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作者：
Zhou, Guangmin;Pei, Songfeng;Cheng, Hui-Ming
锂硫（Li-S）电池具有高比容量，被认为是大规模储能和电动汽车的下一代电池。然而，快速容量衰减和低硫利用率抑制了它们的使用。我们设计了一种独特的三明治结构，在两个石墨烯膜之间使用纯硫，在大面积上连续生产，作为一种非常简单但有效的方法，用于制造具有超快充电/放电速率和长寿命的Li-S电池。使用一个膜作为石墨烯集流体（GCC）以代替常规铝箔集流体，并且将硫涂覆到该膜上作为活性材料。将另一个膜涂覆到常规聚合物隔膜（G-隔膜）上。该电极在300 mA g−1时显示出1340 mA h g −1的高比容量、接近100%的库仑效率、优异的高倍率性能和长循环稳定性。GCC和G-隔板不仅有效地降低了硫阴极的内阻，而且还起到缓冲层的作用，以捕获/固定和再利用溶解的多硫化锂。此外，第一次，三维X射线显微断层扫描被用来研究电化学充电/放电过程中的硫扩散。
Lithium-sulfur (Li–S) batteries have high specific capacities and are considered as next-generation batteries for large-scale energy storage and electric vehicles. However, rapid capacity fade and low sulfur utilisation inhibit their use. We designed a unique sandwich structure with pure sulfur between two graphene membranes, which are continuously produced over a large area, as a very simple but effective approach for the fabrication of Li–S batteries with ultrafast charge/discharge rates and long-life. One membrane was used as a graphene current collector (GCC) to replace the conventional aluminium foil current collector, and sulfur was coated onto this membrane as the active material. The other membrane was coated onto a conventional polymer separator (G-separator). This electrode showed a high specific capacity of 1340 mA h g−1at 300 mA g−1, a Coulombic efficiency approaching 100%, excellent high-rate performance and long cyclic stability. The GCC and G-separator not only effectively reduce the internal resistance of the sulfur cathode but also function as buffer layers to trap/immobilise and reuse the dissolved lithium polysulfides. Furthermore, for the first time, three-dimensional X-ray microtomography was used to investigate sulfur diffusion during electrochemical charge/discharge.