Dai Zudian, Wang Mei, Zhang Yin, Wang Boya, Luo Hang, Zhang Xuemei, Wang Qian, Zhang Yun, Wu Hao
Department of Advanced Energy Materials, College of Material Science and Engineering, Sichuan University, Chengdu, 610064, P. R. China.
Chemistry. 2020 Jul 17;26(40):8784-8793. doi: 10.1002/chem.202000467. Epub 2020 Jun 25.
Lithium-sulfur batteries (LSBs) still suffer from the shuttle effect on the cathode and the lithium dendrite on the anode. Herein, polyacrylonitrile (PAN) is developed into a bifunctional host material to simultaneously address the challenges faced on both the sulfur cathode and lithium anode in LSBs. For the sulfur cathode, PAN is bonded with sulfur to produce sulfurized PAN (SPAN) to avoid the shuttle effect. The SPAN is accommodated into a conductive 3D CNTs-wrapped carbon foam to prepare a self-supporting cathode, which improves the electronic and ionic conductivity, and buffers the volume expansion. Thereby, it delivers reversible capacity, superb rate capability, and outstanding cycling stability. For the Li-metal anode, PAN aerogel is carbonized to give macroporous N-doped cross-linked carbon nanofiber that behaves as a lithiophilic host to regulate Li plating and suppress the growth of Li dendrite. Combining the improvements for both the cathode and anode realizes a remarkable long-term cyclability (765 mAh g after 300 cycles) in a full cell. It provides new opportunity to propel the practical application of advanced LSBs.
锂硫电池（LSBs）仍然受到阴极上的穿梭效应和阳极上的锂枝晶的困扰。在此，聚丙烯腈（PAN）被开发成一种双功能主体材料，以同时应对锂硫电池中硫阴极和锂阳极所面临的挑战。对于硫阴极，PAN与硫结合生成硫化PAN（SPAN）以避免穿梭效应。SPAN被容纳在导电的3D碳纳米管包裹的碳泡沫中，以制备自支撑阴极，这提高了电子和离子导电性，并缓冲了体积膨胀。因此，它具有可逆容量、出色的倍率性能和优异的循环稳定性。对于锂金属阳极，PAN气凝胶被碳化以得到大孔氮掺杂交联碳纳米纤维，其作为亲锂主体来调节锂的沉积并抑制锂枝晶的生长。结合对阴极和阳极的改进，在全电池中实现了显著的长期循环稳定性（300次循环后为765 mAh g）。它为推动先进锂硫电池的实际应用提供了新机会。
