Atomic Iron Catalysis of Polysulfide Conversion in Lithium-Sulfur Batteries
Atomic Iron Catalysis of Polysulfide Conversion in Lithium-Sulfur Batteries
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锂硫电池中原子铁催化多硫化物转化
DOI：
10.1021/acsami.8b03830
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发表时间：
2018-06-13
影响因子：
9.5
通讯作者：
Yang, Wen
中科院分区：
文献类型：
--
作者：
Liu, Zhenzhen;Zhou, Lei;Yang, Wen
锂硫电池由于其高能量密度和低成本而被认为是有前途的储能候选者。开发长期循环稳定性电池是一个主要挑战。在这里，提出了一种催化策略来加速锂硫电池中硫及其放电产物的可逆转化。这是通过多孔氮掺杂碳中的单原子铁活性位点实现的，该碳是通过在铁酞菁和硬模板存在下聚合和碳化二苯胺而制备的。 Fe-PNC/S复合电极在0.1C倍率下循环300次后表现出高放电容量(427 mAh g(-1))，库伦效率高于95.6%。此外，该电极在0.5C下经过300次循环后可提供更高的容量，达到557.4 mAh g(-1)。重要的是，异位SEM显示，与单独的氮掺杂碳相比，Fe-PCN/S具有更小的多硫化物相成核过电势，可形成纳米级Li2S，从而增强了Li2S中锂离子的扩散，因此实现了锂硫电池的高倍率性能和显着的循环寿命。我们的策略为利用原子铁催化进行多硫化物转化以开发高性能锂硫电池开辟了一条新途径。
Lithium-sulfur batteries have been regarded as promising candidates for energy storage because of their high energy density and low cost. It is a main challenge to develop long-term cycling stability battery. Here, a catalytic strategy is presented to accelerate reversible transformation of sulfur and its discharge products in lithium-sulfur batteries. This is achieved with single-atomic iron active sites in porous nitrogen-doped carbon, prepared by polymerizing and carbonizing diphenylamine in the presence of iron phthalocyanine and a hard template. The Fe-PNC/S composite electrode exhibited a high discharge capacity (427 mAh g(-1)) at a 0.1C rate after 300 cycles with the Columbic efficiency of above 95.6%. Besides, the electrode delivers much higher capacity of 557.4 mAh g(-1) at 0.5C over 300 cycles. Importantly, the Fe-PCN/S has a smaller phase nucleation overpotential of polysulfides than nitrogen-doped carbon alone for the formation of nanoscale of Li2S as revealed by ex situ SEM, which enhance lithium-ion diffusion in Li2S, and therefore a high rate performance and remarkable cycle life of Li-sulfur batteries were achieved. Our strategy paves a new way for polysulfide conversion with atomic iron catalysis to exploit high-performance lithium-sulfur batteries.