Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712, USA.
Nat Commun. 2013;4:2985. doi: 10.1038/ncomms3985.
The success of rechargeable lithium-ion batteries has brought indisputable convenience to human society for the past two decades. However, unlike commercialized intercalation cathodes, high-energy-density sulphur cathodes are still in the stage of research because of the unsatisfactory capacity retention and long-term cyclability. The capacity degradation over extended cycles originates from the soluble polysulphides gradually diffusing out of the cathode region. Here we report an applicable way to recharge lithium-sulphur cells by a simple charge operation control that offers tremendous improvement with various lithium-sulphur battery systems. Adjusting the charging condition leads to long cycle life (over 500 cycles) with excellent capacity retention (>99%) by inhibiting electrochemical reactions along with severe polysulphide dissolution. This charging strategy and understanding of the reactions in different discharge steps will advance progress in the development of lithium-sulphur batteries.
在过去的二十年里，可充电锂离子电池的成功为人类社会带来了无可争议的便利。然而，与商业化的嵌入型阴极不同，高能密度的硫阴极仍处于研究阶段，因为其容量保持率和长期循环稳定性不佳。在长期循环过程中，容量的衰减源于可溶性多硫化物逐渐从阴极区域扩散出来。在这里，我们报告了一种通过简单的充电操作控制来给锂-硫电池充电的实用方法，该方法在各种锂-硫电池系统中都有显著的改进。通过抑制电化学反应以及严重的多硫化物溶解，调整充电条件可实现长循环寿命（超过 500 次循环）和优异的容量保持率（>99%）。这种充电策略和对不同放电步骤中反应的理解将推动锂-硫电池的发展。
