College of Materials Science and Engineering, Dalian Jiaotong University
Dalian Institute of Chemical Physics, Chinese Academy of Science

锂硫电池(lithium-sulfurbattery,LSBs)是一种基于多电子转化反应机制的新型锂离子二次电池,具有能量密度高、环境友好、成本低廉的优点。然而,多硫化物的穿梭现象和硫正极反应动力学缓慢限制了LSBs的实用性。设计了一种负载镍铁双金属单原子催化剂的多孔空心碳球(NiFe-HCS)用作高效的硫载体纳米反应器。NiFe-HCS具有高比表面积,可以实现高的硫载量,且其空腔结构可以缓冲硫的体积膨胀。原子级Ni与Fe提供了丰富的化学吸附位点,不仅能够通过强的物理束缚和化学吸附能力抑制多硫化物的溶解和扩散,而且能够提高硫的利用率,促进多硫化物的反应还原动力学,有效地提高其催化转化效率。因此,基于NiFe-HCS纳米反应器的LSBs实现了高比容量、高倍率性能和超长的循环稳定性,在2C电流密度下初始的质量比容量为1002mAh/g,经过500次循环,电容量保持率为94%,并且在8C电流密度下表现出优异的高倍率性能,质量比容量为932mAh/g,显示了此纳米反应器在高能量密度锂硫电池中的巨大应用潜力。

Lithium-sulfur batteries (LSBs) are a new type of lithium-ion secondary bat- tery based on a multi-electron conversion reaction mechanism. It has the advantages of high theo- retical energy density, environmental compatibility, and cost-effectiveness. However, the shuttle effect of soluble polysulfides and sluggish electrochemical kinetics at the sulfur cathode limit the practicality of LSBs. A NiFe bimetallic single-atom catalyst supported on hollow carbon spheres (NiFe-HCS) was designed to serve as an efficient sulfur host and nanoreactor. NiFe-HCS fea- tures a high specific surface area, allowing for a high sulfur loading capacity, and its hollow structure can accommodate the volume expansion of sulfur. The atomic-level NiFe provides abun- dant chemical adsorption sites, which not only inhibit the dissolution and diffusion of polysulfides through strong physical confinement and chemical adsorption but also enhance sulfur utilization and promote the reduction reaction kinetics of polysulfides, thereby effectively improving catalyt- ic conversion efficiency. As a result, LSBs based on the NiFe-HCS nanoreactor achieve high spe- cific capacity, excellent rate performance, and ultra-long cycling stability. At a current density of C, the mass specific capacity reaches mAh/g, with a capacity retention ratio of 94% after cycles. Additionally, the battery exhibites excellent high-rate performance, delivering a mass specific capacity of mAh/g at curvent density of C. These results demonstrate the signifi- cant potential of this nanoreactor in high energy density lithium-sulfur batteries.

国家自然科学基金青年基金项目(NSFC22302027,NSFC22172161)和大连市青年科技之星项目(2022RQ030).

任小敏,姜 松,韩 雨,等.中空碳球负载的镍铁双金属单原 子 催 化 剂 用 于 高 性 能 锂 硫 电 池 研 究[J].煤 炭 转 化,2024,47(6):57-66

REN Xiaomin,JIANG Song,HAN Yu,et al.Study on Ni-Fe bimetallic single-atom catalyst loaded on hollow carbon spheres for high-performance lithium-sulfur batteries[J].Coal Conversion,2024,47(6):57-66