南开大学林力团队报道了电偶极畴拓扑绝缘体异质结促进锂硫电池中多硫化物的转化。相关研究成果于2025年1月2日发表于国际一流学术期刊《德国应用化学》。

异质结材料被认为是有前景的电催化剂候选者，可以增强先进的锂硫（Li-S）电池的性能。然而，异质结材料促进硫氧化还原反应动力学的详细作用机制尚不清楚。

该文中，研究人员构建了一个具有电偶极畴的多功能势阱型Bi₂Te₃/TiO₂拓扑绝缘体（TI）异质结，以阐明其协同机制，该机制有助于快速传质，增强多硫化物捕获能力，加速多硫化物转化。

因此，采用Bi₂Te₃/TiO₂-TI异质结改性隔膜的Li-S电池实现了硫阴极的高利用率，在0.2℃下提供1375 mAh g^-1的高可逆比容量，在1℃下1000次循环中，每次循环的容量衰减可忽略不计，为0.022%。即使硫负载高达13.2 mg cm^-2，E/S比低至3.8μL mg^-1，也可以获得11.2 mAh cm^-2的高面积容量和可接受的循环稳定性。

该项工作为设计高效TI异质结促进Li-S电池的实际应用提供了指导。

附：英文原文

Title: Topological Insulator Heterojunction with Electric Dipole Domain to Boost Polysulfide Conversion in Lithium-Sulfur Batteries

Author: Hedong Chen, Yecheng Qiu, Zhiyuan Cai, Wenhao Liang, Lin Liu, Manman Li, Xianhua Hou, Fuming Chen, Xunzhu Zhou, Tengfei Cheng, Liqing He, Jiazhao Wang, Xiao Zhang, Shixue Dou, Lin Li

Issue&Volume: 2025-01-02

Abstract: The heterojunction materials are considered as promising electrocatalyst candidates that empower advanced lithium-sulfur (Li-S) batteries. However, the detailed functional mechanism of heterojunction materials to boost the sulfur redox reaction kinetics remains unclear. Herein, we construct a multifunctional potential well-type Bi2Te3/TiO2 topological insulator (TI) heterojunction with electric dipole domain to elucidate the synergistic mechanism, which facilitates rapid mass transport, strengthens polysulfide capture ability and accelerates polysulfide conversion. Therefore, the Li-S battery with Bi2Te3/TiO2 TI heterojunction modified separator achieves high utilization of sulfur cathode, delivering a high reversible specific capacity of 1375 mAh g-1 at 0.2 C and long cycling capability with a negligible capacity decay of 0.022% per cycle over 1000 cycles at 1 C. Even with the high sulfur loading of 13.2 mg cm-2 and low E/S ratio of 3.8 μL mg-1, a high area capacity of 11.2 mAh cm-2 and acceptable cycling stability can be obtained. This work provides guidance for designing high-efficiency TI heterojunctions to promote the practical application of Li-S batteries.

DOI: 10.1002/anie.202423357

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202423357