In situ assembly of 2D conductive vanadium disulfide with graphene as a high-sulfur-loading host for lithium–sulfur batteries
In situ assembly of 2D conductive vanadium disulfide with graphene as a high-sulfur-loading host for lithium–sulfur batteries
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二维导电二硫化钒与石墨烯的原位组装作为锂硫电池的高硫负载主体
DOI：
10.1002/aenm.201800201
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发表时间：
2018
影响因子：
27.8
通讯作者：
Zhongfan Liu
中科院分区：
文献类型：
--
作者：
Xingyu Zhu;Wen Zhao;Yingze Song;Qiucheng Li;Feng Ding;Jingyu Sun;Li Zhang;Zhongfan Liu
锂硫(Li-S)电池因其能量密度高、成本低、环境友好等优点而被认为是最有前途的储能技术之一。然而，现有的缺点包括中间多硫化物的穿梭、硫的绝缘性以及硫阴极的体积变化很大，否则会导致容量衰减和循环不稳定。为了克服这些挑战，本文提出了一种原位组装路线来制备VS2/还原石墨烯氧化物纳米片(G-VS2)作为硫载体。得益于石墨烯骨架中的2D导电和极性VS2夹层，所得到的G-VS2杂化材料能够有效地抑制多硫化物的穿梭，促进电荷传输，并在结构约束和化学锚定的协同作用下缓冲体积膨胀。利用这些优点，所得到的硫磺正极(G-VS2/S)可以提供出色的倍率性能(分别为1℃和2℃时的≈950和800mAhg−1)和令人印象深刻的高倍率循环稳定性(在5℃下300次循环后仍保持≈532mAhg−1)。更重要的是，即使在高电流密度下，它也能使高硫负极具有优异的循环性能(在0.2℃时，面积容量达到5.1mAhm−2at 0.2℃，硫负载量为5 mg cm−2)。
Lithium–sulfur (Li–S) batteries are deemed to be one of the most promising energy storage technologies because of their high energy density, low cost, and environmental benignancy. However, existing drawbacks including the shuttling of intermediate polysulfides, the insulating nature of sulfur, and the considerable volume change of sulfur cathode would otherwise result in the capacity fading and unstable cycling. To overcome these challenges, herein an in situ assembly route is presented to fabricate VS2/reduced graphene oxide nanosheets (G–VS2) as a sulfur host. Benefiting from the 2D conductive and polar VS2interlayered within a graphene framework, the obtained G–VS2hybrids can effectively suppress the polysulfide shuttling, facilitate the charge transport, and cushion the volume expansion throughout the synergistic effect of structural confinement and chemical anchoring. With these advantageous features, the obtained sulfur cathode (G–VS2/S) can deliver an outstanding rate capability (≈950 and 800 mAh g−1at 1 and 2 C, respectively) and an impressive cycling stability at high rates (retaining ≈532 mAh g−1after 300 cycles at 5 C). More significantly, it enables superior cycling performance of high‐sulfur‐loading cathodes (achieving an areal capacity of 5.1 mAh cm−2at 0.2 C with a sulfur loading of 5 mg cm−2) even at high current densities.