水系锂离子电池负极聚硫代苯醌的合成与电化学性能

通过硫化聚合的方法,以四氯苯醌(TCQ)为单体合成了聚硫代苯醌(PBQS)材料。本文改变S的加入量,探讨了不同摩尔比的S和Na₂S对PBQS电极电化学性能的影响。当S和Na₂S摩尔比为0.4时,形成两个氯原子被硫取代的PBQS-0.4稳定结构。PBQS-0.4电极放电比容量达到140 mAh·g^-1以上,显现出良好的循环稳定性和优异的倍率性能。而当S和Na₂S摩尔比降至0.25时,氯取代不完全、聚合程度不高; S和Na₂S摩尔比增至0.7 : 1时,聚合物中可能形成了不稳定的累积S-S键;上述两方面都导致电极性能明显下降。

Synthesis and Electrochemical Performance of a Benzoquinone-Based Polymer Anode for Aqueous Lithium-Ion Batteries

Using the tetrachloro-p-benzoquinone (TCQ) monomer, poly(benzoquinonyl sulfide) (PBQS) was synthesized by a simple polycondensation reaction. The influence of the molar ratio of S to Na₂S on the electrochemical performance of a PBQS anode was assessed by changing the amount of S added. The results showed that the electrochemical performance of PBQS strongly depended on the molar ratio of S to Na₂S. When the molar ratio of S to Na₂S was 0.4, two Cl were replaced by S, and PBQS with a stable structure was obtained. The discharge capacity of PBQS exceeded 140 mAh·g^-1. At the same time, PBQS displayed satisfactory rate capability and excellent cyclability. Conversely, when the molar ratio of S to Na₂S was decreased to 0.25, Cl was not substituted completely and the polymerization degree was low. Upon increasing the molar ratio of S to Na₂S to 0.7, an unstable S-S bond may form in the polymer. The above two factors degraded the electrode performance of these materials.