Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002, People's Republic of China.
State Key Laboratory of Coordination Chemistry, MOE Key Laboratory of Mesoscopic Chemistry, MOE Key Laboratory of High Performance Polymer Materials and Technology, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, People's Republic of China.
ACS Nano. 2023 Jun 27;17(12):11527-11536. doi: 10.1021/acsnano.3c01469. Epub 2023 Jun 8.
High-performance lithium-sulfur (Li-S) batteries that can work normally under harsh conditions have attracted tremendous attention; however, the sluggish reaction kinetics of polysulfide conversions at low temperatures as well as the notorious polysulfide shuttling at high temperatures remain to be resolved. Herein, a multibranched vanadium nitride (MB-VN) electrocatalyst has been designed and deployed for Li-S batteries. Both experimental (time-of-flight secondary ion mass spectroscopy and adsorption tests) and theoretical results verify the strong chemical adsorption capability and high electrocatalytic activity of MB-VN with respect to polysulfides. Moreover, in situ Raman characterization manifests the effective inhibition of polysulfide shuttling by the MB-VN electrocatalyst. Using MB-VN-modified separators, the Li-S batteries deliver an excellent rate capability (707 mAh g at 3.0 C) and great cyclic stability (678 mAh g after 400 cycles at 1.0 C) at room temperature. With 6.0 mg cm of sulfur and a lean electrolyte volume of ∼6 μL mg, Li-S batteries exhibit a high areal capacity of 5.47 mAh cm. Even over a wide temperature range (-20 to +60 °C), the Li-S batteries still maintain stable cyclic performance at high current rates. This work demonstrates that metal nitride based electrocatalysts can realize low-/high-temperature-tolerant Li-S batteries.
具有在恶劣条件下正常工作能力的高性能锂硫（Li-S）电池引起了极大的关注；然而，低温下多硫化物转化的反应动力学缓慢以及高温下臭名昭著的多硫化物穿梭问题仍然需要解决。在此，设计并部署了一种多分支氮化钒（MB-VN）电催化剂用于 Li-S 电池。实验（飞行时间二次离子质谱和吸附测试）和理论结果均验证了 MB-VN 对多硫化物具有很强的化学吸附能力和高电催化活性。此外，原位拉曼表征表明 MB-VN 电催化剂能有效抑制多硫化物穿梭。使用 MB-VN 改性的隔膜，Li-S 电池在室温下表现出优异的倍率性能（在 3.0 C 时为 707 mAh g）和出色的循环稳定性（在 1.0 C 时经过 400 次循环后为 678 mAh g）。对于 6.0 mg cm 的硫和约 6 μL mg 的贫电解质体积，Li-S 电池表现出 5.47 mAh cm 的高面容量。即使在很宽的温度范围内（-20 至 +60 °C），Li-S 电池仍能在高电流速率下保持稳定的循环性能。这项工作表明，基于金属氮化物的电催化剂可以实现低温/高温耐受的 Li-S 电池。
