博文

云师大物电学院王洪恩教授在《Journal of Colloid and Interface Science》发表成果

已有 517 次阅读 2025-3-31 12:55 |个人分类:个人原创|系统分类:论文交流

2025年3月30日，Elsevier 旗下top期刊《Journal of Colloid and Interface Science》在线发表了云南师范大学物理与电子信息学院王洪恩教授最新研究成果《Interface control in TiO2/BaTiO3 ferroelectric heterostructures: A bidirectional catalytic pathway toward high-performance Li-S batteries》。云南师范大学物理与电子信息学院为第一作者单位，王洪恩教授为通讯作者，合作单位为西北师范大学、浙江科技大学、湖南科技学院和重庆科技大学。

https://www.sciencedirect.com/science/article/pii/S0021979725008586

微信截图_20250331125326.png

Abstract

Li-S batteries (LSBs), noted for their high energy density and low cost, face challenges due to sluggish lithium polysulfide (LiPS) redox kinetics and complex phase transformations during charge/discharge cycles. Herein, we introduce a novel hollow nanocomposite, a titanium oxide/barium titanate (TiO2/BaTiO3) heterostructure with an ultrathin carbon coating, designed to act as a bidirectional electrocatalyst, enhancing the sequential conversion of sulfur (S8) to Li2S4 and then to lithium sulfide (Li2S). The ferroelectric nature of BaTiO3 enhances LiPS adsorption, reducing the shuttling effect and improving battery performance. The interface-induced electric field directs LiPS migration to TiO2, facilitating the redox process. An applied electric field polarizes the heterostructure, optimizing the dipole moment of BaTiO3 and further enhancing performance. Electrochemical measurements and theoretical calculations confirm the superior electrocatalytic activity of TiO2/BaTiO3@C for LiPS redox kinetics. The composite electrode achieves a high initial capacity of 836 mAh g−1 at 1C, retaining 64 % of its capacity after 400 cycles with a low fading rate of 0.075 % per cycle. Under practical operation conditions (sulfur areal loading: 6.02 mg cm−2; electrolyte/sulfur (E/S) ratio: 6.5 μL mg−1), the as-fabricated LSBs still demonstrate good areal capacities of 5.18, 4.09, 3.84, 3.64, and 3.15 mAh cm−2, respectively, at current densities from 0.05 to 0.5C. This study elucidates the critical synergy between self-induced electric fields and heterostructure engineering in polysulfide conversion, providing fundamental guidance for designing advanced catalysts in high-energy LSBs and related electrochemical energy systems.