Taming polysulfides in sulfur-based batteries via electrolyte-soluble thiomolybdate additives
Taming polysulfides in sulfur-based batteries via electrolyte-soluble thiomolybdate additives
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通过电解质可溶性硫代钼酸盐添加剂驯化硫基电池中的多硫化物
DOI：
10.1039/d2ta03893e
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发表时间：
2022
影响因子：
11.9
通讯作者：
Manthiram, Arumugam
中科院分区：
文献类型：
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作者：
Asl, Hooman Yaghoobnejad;Bhargav, Amruth;Manthiram, Arumugam
硫基二次电池作为电化学能量储存的可持续和低成本替代品的前景长期以来一直受到多硫化物穿梭问题的阻碍。在本文中，我们证明了利用基于（氧代）硫代钼酸盐的电解质可溶性添加剂作为减轻二次硫基电池中多硫化物穿梭的影响的工具。通过各种技术，它表明，含钼的阴离子添加剂进行自发的亲核反应的高度可溶性，长链多硫化物通过中性S-原子转移过程，产生较高的S/Mo比配合物沿着与短链多硫化物。更重要的是，它示出了如何在钼中心上的O/S原子取代可以通过降低均裂S-S键断裂能诱导酶水平的增强上述反应速率。最后，通过阳极级检查，人们意识到，锂的树枝状电镀在含氧/硫代钼酸盐的系统中得到了相当大的抑制，从而降低了电池阻抗和过电位，从而显著提高了循环寿命。在具有高硫负载和贫电解质组成的Li-S电池中，稳定的循环寿命和0.1%/循环的低容量衰减率证明了增加的多硫化物吸收反应动力学的积极影响。
The promise of secondary sulfur-based batteries as a sustainable and low-cost alternative to electrochemical energy storage has been long held back by the polysulfide shuttle problem. Herein, we demonstrate the utilization of electrolyte-soluble additives based on (oxo)thiomolybdate as a tool to mitigate the effect of the polysulfide shuttle in secondary sulfur-based batteries. Through a variety of techniques, it is shown that the Mo-containing anionic additives undergo spontaneous nucleophilic reactions with the highly soluble, long-chain polysulfides via a neutral S-atom transfer process, yielding higher S/Mo ratio complexes along with short-chain polysulfides. More importantly, it is shown how the O/S atomic substitution on the molybdenum center can induce enzymatic-level enhancement in the above reaction rate by lowering the homolytic S–S bond cleavage energy. Lastly, through anode-level inspections, it was realized that the dendritic electroplating of Li was suppressed considerably in the system with oxo/thiomolybdate, thereby reducing the cell impedance and overpotential, leading to significantly improved cycle-life. The positive influence of the increased polysulfide uptake reaction kinetics is evidenced by stable cycle-life and a low capacity-fade rate of 0.1% per cycle in Li–S cells with a high sulfur loading and lean electrolyte compositions.