Zhou Xiaoya, Mao Wei, Ye Chengwei, Liang Qi, Wang Peng, Wang Xuebin, Tang Shaochun
Key National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, People's Republic of China.
Nanomicro Lett. 2025 Jun 23;17(1):308. doi: 10.1007/s40820-025-01806-0.
Electrocatalyst activity and stability demonstrate a "seesaw" relationship. Introducing vacancies (Vo) enhances the activity by improving reactant affinity and increasing accessible active sites. However, deficient or excessive Vo reduces polysulfide adsorption and lowers catalytic stability. Herein, a novel "heteroatoms synergistic anchoring vacancies" strategy is proposed to address the trade-off between high activity and stability. Phosphorus-doped CoSe with remained rich selenium vacancies (P-CS-Vo-0.5) was synthesized by producing abundant selenium Vo followed by controlled P atom doping. Atomic-scale microstructure analysis elucidated a dynamic process of surface vacancy generation and the subsequent partial occupation of these vacancies by P atoms. Density functional theory simulations and in situ Raman tests revealed that the Se vacancies provide highly active catalytic sites, accelerating polysulfide conversion, while P incorporation effectively reduces the surface energy of Se vacancies and suppresses their inward migration, enhancing structural robustness. The battery with the optimal P-CS-Vo-0.5 separator delivers an initial discharge capacity of 1306.7 mAh g at 0.2C, and maintain 5.04 mAh cm at a high sulfur loading (5.7 mg cm, 5.0 μL mg), achieving 95.1% capacity retention after 80 cycles. This strategy of modifying local atomic environments offers a new route to designing highly active and stable catalysts.
电催化剂的活性和稳定性呈现出一种“跷跷板”关系。引入空位（Vo）可通过提高反应物亲和力和增加可及活性位点来增强活性。然而，Vo不足或过多会降低多硫化物吸附并降低催化稳定性。在此，提出了一种新颖的“杂原子协同锚定空位”策略来解决高活性和稳定性之间的权衡问题。通过产生大量硒空位，随后进行可控的磷原子掺杂，合成了具有丰富硒空位的磷掺杂CoSe（P-CS-Vo-0.5）。原子尺度的微观结构分析阐明了表面空位产生的动态过程以及随后这些空位被磷原子部分占据的情况。密度泛函理论模拟和原位拉曼测试表明，硒空位提供了高活性催化位点，加速了多硫化物转化，而磷的掺入有效降低了硒空位的表面能并抑制了它们向内迁移，增强了结构稳定性。采用最佳P-CS-Vo-0.5隔膜的电池在0.2C下的初始放电容量为1306.7 mAh g，在高硫负载（5.7 mg cm，5.0 μL mg）下保持5.04 mAh cm，80次循环后容量保持率达到95.1%。这种修饰局部原子环境的策略为设计高活性和稳定的催化剂提供了一条新途径。
