Rooting MnO2 nanosheet on carbon nanoboxes as efficient catalytic host for lithium–sulfur battery
Rooting MnO2 nanosheet on carbon nanoboxes as efficient catalytic host for lithium–sulfur battery
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DOI：
10.1007/s10008-020-04828-3
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发表时间：
2020-09
影响因子：
2.5
通讯作者：
T. Peng;Ning Zhang;Yangbo Wang;Menglong Zhao;Weiwei Sun;Deyang Zhang;Hailong Yan;Yang Lu;Yongsong Luo
中科院分区：
文献类型：
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作者：
T. Peng;Ning Zhang;Yangbo Wang;Menglong Zhao;Weiwei Sun;Deyang Zhang;Hailong Yan;Yang Lu;Yongsong Luo
锂硫（Li-S）电池是最有前途的储能系统之一，其理论容量为2600 Wh kg−1。然而，可溶性多硫化锂（LiPSs）的穿梭效应导致严重的容量衰减，阻碍了其实际应用。本论文研究了以高硫含量的碳纳米盒（C NB）为载体的双极性MnO 2纳米片作为新型锂硫电池的有效载体。碳纳米盒有效地限制了活性物种，并提供了大的空间来缓解充电/放电过程中的体积膨胀。该极性MnO 2纳米片对LiPS有很强的吸附作用，并催化可溶性多硫化物转化为不溶性Li 2S 2/Li 2S，再还原为硫。结果，多硫化物溶解和穿梭效应被有效地最小化。以S/MnO2@C NBs为正极组装的锂硫电池具有上级电化学性能。在0.2 C下循环200次后，放电容量达到856 mAh g-1。2 C时容量也可达到720 mAh g− 1，比用S/C NB电极组装的电池高出约2倍。
Lithium–sulfur (Li–S) battery is one of the most promising energy storage systems for its ultrahigh theoretical capacity of 2600 Wh kg−1. However, the shuttle effect of soluble lithium polysulfides (LiPSs) leads to severe capacity decay and hinders its practical application. In this work, ultrathin polar MnO2nanosheets rooting on carbon nanoboxes (C NBs) with high sulfur content have been studied as efficient host for advanced Li–S battery. The carbon nanoboxes confine the active species efficiently and provide large space to relieve the volume expansion during charging/discharging process. The polar MnO2nanosheets have strong absorption for LiPSs and catalyze the conversion of soluble polysulfides to insoluble Li2S2/Li2S and back to sulfur. As a result, the polysulfide dissolution and shuttle effect are minimized effectively. Li–S battery assembled with S/MnO2@C NBs cathode shows superior electrochemical performance. The discharge capacity of 856 mAh g−1is attained after 200 cycles at 0.2 C. The capacity can also reach 720 mAh g−1at 2 C, which is about 2 times higher than the battery assembled with S/C NB electrode.