Replacement of rare metal oxides-based positive electrode materials used in rechargeable lithium batteries by redox active organic compounds

在可充电锂电池中使用一系列氧化还原活性有机化合物，而不是稀有（少量）金属氧化物，是缓解资源问题的一种方法。为了实现这种有机可充电电池，开发一种既满足高容量又满足长循环寿命的高性能有机活性材料是必不可少的。在本研究中，我们评估了几种基于苯醌骨架的有机正极活性材料，并发现了循环稳定性与电解质溶剂溶解度之间的相关性。特别是，小极性基团的引入是在不牺牲放电容量的情况下提高有机活性材料循环寿命性能的有效途径。所获得的实验结果将有助于开发一种耐多次循环的新型有机活性材料。

Using a series of redox active organic compounds, instead of rare (minor) metal oxides, in rechargeable lithium batteries is a way to alleviate the resource problem. To realize such organic rechargeable batteries, the development of a high-performance organic active material, which satisfies both of high capacity and long cycle-life, is indispensable. In this study, we evaluated several organic positive-electrode active materials based on the benzoquinone skeleton, and found a correlation between the cycle-stability and the solubility in the electrolyte solvent. In particular, the introduction of small polar groups was revealed to be an effective way to improve the cycle-life performance of organic active materials without sacrificing the discharge capacities. The obtained experimental results will contribute to the development of a new organic active material that can tolerate many cycles.