Ye Zhidong, Gan Linfeng, He Yaxiong, Jiang Qi
Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle (Ministry of Education), Southwest Jiaotong University, Chengdu, 610031, China; Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle (Ministry of Education), Southwest Jiaotong University, Chengdu, 610031, China; Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
J Colloid Interface Sci. 2025 Nov;697:137943. doi: 10.1016/j.jcis.2025.137943. Epub 2025 May 20.
The practical application of lithium-sulfur (Li-S) batteries faces numerous challenges, primarily due to the shuttle effect of soluble lithium polysulfides (LiPSs) and the sluggish electrochemical reaction kinetics during their conversion to LiS, resulting in poor cycling performance. To address these issues, this study employed a vapor deposition technique to in situ construct a CoS@CoO heterostructure with superior interfacial properties on a CoO substrate, followed by crosslinking and optimization with reduced graphene oxide (rGO). Density functional theory (DFT) calculations reveal for the first time that the incorporation of S effectively modulates the d-band center of Co, which not only enhances the chemical adsorption capability of the heterointerface toward lithium polysulfides but also optimizes the catalytic pathway for sulfur species conversion. Comprehensive experimental results and theoretical calculations confirm that the CoS@CoO heterostructure exhibits multiple advantages, including strong adsorption capability, high catalytic activity, rapid Li transport efficiency, and excellent electrical conductivity. The CoS@CoO heterostructure not only significantly suppresses the LiPSs shuttle effect but also greatly accelerates the electrochemical reaction kinetics of LiPSs and LiS. Compared to materials composed solely of CoS or CoO, the CoS@CoO heterostructure demonstrates synergistically enhanced electrochemical performance in Li-S batteries. At a current density of 2C, a representative Li-S battery achieves nearly 100 % Coulombic efficiency, with a reversible specific capacity of 827 mAh g retained after 1000 cycles, corresponding to a capacity decay rate of only 0.007 % per cycle. Even under high sulfur loading conditions (5.1 mg cm), the battery maintains stable cycling performance. This work provides novel insights and directions for designing multifunctional heterostructures with synergistic effects for applications in lithium-ion batteries and catalytic fields.
锂硫（Li-S）电池的实际应用面临众多挑战，主要是由于可溶性多硫化锂（LiPSs）的穿梭效应以及它们转化为LiS过程中缓慢的电化学反应动力学，导致循环性能较差。为了解决这些问题，本研究采用气相沉积技术在CoO衬底上原位构建具有优异界面性能的CoS@CoO异质结构，随后用还原氧化石墨烯（rGO）进行交联和优化。密度泛函理论（DFT）计算首次表明，S的掺入有效地调节了Co的d带中心，这不仅增强了异质界面对多硫化锂的化学吸附能力，还优化了硫物种转化的催化途径。综合实验结果和理论计算证实，CoS@CoO异质结构具有多种优势，包括强吸附能力、高催化活性、快速的Li传输效率和优异的导电性。CoS@CoO异质结构不仅显著抑制了LiPSs的穿梭效应，还大大加速了LiPSs和LiS的电化学反应动力学。与仅由CoS或CoO组成的材料相比，CoS@CoO异质结构在Li-S电池中表现出协同增强的电化学性能。在2C的电流密度下，代表性的Li-S电池实现了近100%的库仑效率，在1000次循环后可逆比容量保持在827 mAh g，对应于仅0.007%的每循环容量衰减率。即使在高硫负载条件下（硫负载量为5.1 mg cm），电池仍保持稳定的循环性能。这项工作为设计具有协同效应的多功能异质结构在锂离子电池和催化领域的应用提供了新的见解和方向。
