Vallem Sowjanya, Song Seunghyun, Oh Yoonju, Bae Joonho
Department of Physics, Gachon University, Seongnam-si, Gyeonggi-do, 461-701, South Korea.
Small Methods. 2024 Oct;8(10):e2400294. doi: 10.1002/smtd.202400294. Epub 2024 Mar 28.
Selenium-based electrodes have garnered attention for their high electrical conductivity, compatibility with carbonate electrolytes, and volumetric capacity comparable to sulfur electrodes. However, real-time application is hindered by rapid capacity deterioration from the "shuttle effect" of polyselenides and volume fluctuations. To address these challenges, a hybrid Se@ZIF-67/Mo-MXene-derived (Se@Co-NC/MoC) nanoarchitecture is developed via an economically viable in situ electrostatic self-assembly of ZIF-67 and MoC nanosheets. The catalytic effects and porous framework of Co-NC/MoC enhance electrode attributes, promoting superior adsorption and conversion of lithium polyselenides and facile ion/electron transport within the electrode, resulting in stable electrochemical performance. Lithium-selenium batteries (LSeBs) exhibit remarkable characteristics, boasting high specific capacity and exceptional durability. The Se@Co-NC/MoC electrode delivers a reversible capacity of 503.5 mAh g at 0.5 C with 98% capacity retention, 100% Coulombic efficiency, and exceptional cyclic durability through 8600 cycles. In sustainability tests at 10C/1C charging/discharging, the Se@Co-NC/MoC electrode demonstrates an optimistic and stable capacity of ≈370.6 mAh g with 93% capacity retention at the 3100 cycle in a carbonate-based electrolyte and ≈181.3 mAh g with 92% capacity retention after 5000 cycles in an ether-based electrolyte, indicating exceptional stability for practical rechargeable batteries. This cost-effective and efficient approach holds significant potential for high-performance and durable LSeBs.
基于硒的电极因其高电导率、与碳酸盐电解质的兼容性以及与硫电极相当的体积容量而备受关注。然而,多硒化物的“穿梭效应”导致的快速容量衰减和体积波动阻碍了其实际应用。为应对这些挑战,通过经济可行的原位静电自组装ZIF-67和MoC纳米片,开发了一种混合Se@ZIF-67/Mo-MXene衍生的(Se@Co-NC/MoC)纳米结构。Co-NC/MoC的催化作用和多孔框架增强了电极属性,促进了多硫化锂的优异吸附和转化以及电极内离子/电子的便捷传输,从而产生稳定的电化学性能。锂硒电池(LSeBs)具有显著特点,具有高比容量和出色的耐久性。Se@Co-NC/MoC电极在0.5 C下可逆容量为503.5 mAh g,容量保持率为98%,库仑效率为100%,并通过8600次循环具有出色的循环耐久性。在10C/1C充电/放电的可持续性测试中,Se@Co-NC/MoC电极在基于碳酸盐的电解质中,在第3100次循环时表现出约370.6 mAh g的乐观且稳定的容量,容量保持率为93%;在基于醚的电解质中,5000次循环后容量约为181.3 mAh g,容量保持率为92%,表明其对实际可充电电池具有出色的稳定性。这种经济高效的方法对于高性能和耐用的LSeBs具有巨大潜力。