Zhang Zexian, Luo Guanyu, Zhou Shiyuan, Zeng Wenyan, Mei Tao, Chen Zihe, Yu Xuefeng, Xiao Xiang, Wang Xianbao
Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Overseas Expertise Introduction Center for Discipline Innovation (D18025), Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, School of Materials Science and Engineering, Hubei University, Wuhan 430062, PR China.
ACS Appl Mater Interfaces. 2021 Mar 31;13(12):14169-14180. doi: 10.1021/acsami.0c22597. Epub 2021 Mar 22.
In consideration of the inferior rate performance and low sulfur utilization of lithium-sulfur batteries (LSBs), an effective strategy via combining polar materials with the conductive carbon sulfur host is widely applied. Herein, metal organic framework-derived in situ-developed ZnInS@C is innovatively synthesized to mediate lithium polysulfide (LPS) conversion based on high electron conductivity and strong chemical interactions for advanced LSBs. Polar ZnInS possesses strong chemisorption in keeping with the DFT calculation results and catalytic for LPSs, ensuring a high sulfur utilization. Meanwhile, the hollow non-polar carbon frame possessing hierarchical pores not only provides internal space to contain active species but also accommodates efficient electronic transferring and diffusion of lithium ions in the process of cycling. The above advantages make the electrode possess promising stability and good rate performances, achieving long-term and high-rate cycling. Thus, under a sulfur loading of 1.5 mg cm, after 500 cycles, at 2 and 5 C, the as-prepared ZnInS@C@S delivers reversible capacities of 734 mA h g (75.7% of the initial capacity with a dropping rate of 0.015% per cycle) and 504 mA h g (68.5% of the primal capacity with a dropping rate of 0.029% per cycle), respectively. Even at a high sulfur loading of 5.0 mg cm, at 5 C, 65.6% of the initial capacity can be maintained with a low fading rate of 0.430% per cycle after 500 loops with a high Coulombic efficiency of around 99.8%.
鉴于锂硫电池（LSB）的倍率性能较差且硫利用率较低，一种将极性材料与导电碳硫主体相结合的有效策略被广泛应用。在此，创新性地合成了金属有机框架衍生的原位生长的ZnInS@C，基于其高电子导电性和强化学相互作用来介导多硫化锂（LPS）转化，以用于先进的LSB。极性ZnInS具有与密度泛函理论计算结果相符的强化学吸附作用且对LPS具有催化作用，确保了高硫利用率。同时，具有分级孔的中空非极性碳框架不仅提供了容纳活性物质的内部空间，还在循环过程中促进了锂离子的有效电子转移和扩散。上述优点使该电极具有良好的稳定性和倍率性能，实现了长期和高倍率循环。因此，在硫负载量为1.5 mg cm时，经过500次循环后，在2 C和5 C下，所制备的ZnInS@C@S分别具有734 mA h g（占初始容量的75.7%，每循环下降率为0.015%）和504 mA h g（占初始容量的68.5%，每循环下降率为0.029%）的可逆容量。即使在硫负载量高达5.0 mg cm且在5 C的条件下，经过500次循环后，仍可保持65.6%的初始容量，每循环的低衰减率为0.430%，库仑效率约为99.8%。
