用于锂硫电池高效硫载体的Co‑N‑C@KB复合材料的规模化制备策略

Scale‑Up Strategy to Develop Highly‑Effective Co‑N‑C@KB Composites as Sulfur Host for Lithium‑Sulfur Battery

硫正极较差的性能严重阻碍了锂硫电池的商业化进程,这些因素包括较低的导电能力以及在促进多硫化物转化方面较差的催化活性。我们开发了一种基于配体调控合成和低温热解的规模化策略来制备高效的正极复合材料(Co‑N‑C@KB),这种材料由富含Co‑N‑C活性位点的科琴黑(KB)组成。原子级分散的Co‑N‑C活性位点被证明有利于多硫化物在正极的转化,因而可以提高锂硫电池的容量和循环寿命。基于此,Co‑N‑C@KB作为正极可以使锂硫电池获得高达1442 mAh·g^(-1)的初始放电容量,并且该电池在长时间的稳定性测试中具有出色的容量保持能力。

The commercialization process of Li‑S battery is seriously impeded by the poor performance of sulfur cathode,including the low conductivity and dissatisfactory activity for facilitating the polysulfide conversion.In this work,we developed a scale‑up method to synthesize an efficient cathode material(Co‑N‑C@KB)with abundant Co‑N‑C active sites on the Ketjen Black(KB),through a ligand‑mediated‑synthesis and a low‑temperature‑pyrolysis strategy.The uniformly distributed Co‑N‑C active sites were proved to be favorable for the conversion of polysulfide at the cathode,hence improving the capacity and cyclic life of Li‑S battery.As a result,the Co‑N‑C@KB cathode for the Li‑S battery could deliver an initial discharge specific capacity as high as 1442 mAh·g^(-1),and have the excellent capability for capacity retention during the long‑term stability test.