VPO4@C/graphene microsphere as a potential anode material for lithium-ion batteries
VPO4@C/graphene microsphere as a potential anode material for lithium-ion batteries
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DOI：
10.1016/j.ceramint.2018.05.056
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发表时间：
2018-08
影响因子：
5.2
通讯作者：
Linbo Tang;X. Bin;Chang-sheng An;Hui Li;Zhenjiang He;Jun‐chao Zheng
中科院分区：
文献类型：
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作者：
Linbo Tang;X. Bin;Chang-sheng An;Hui Li;Zhenjiang He;Jun‐chao Zheng
由MO 6八面体和PO 4四面体相互连接而成的三维PO 4基聚阴离子结构，如VPO 4，由于其优异的循环稳定性，是潜在的锂离子电池负极材料。然而，VPO 4作为阳极材料的应用受到其低电导率和剧烈体积膨胀的限制。本文设计并合成了VPO4@C/石墨烯微球。P通过P-C键共价连接VPO 4和石墨烯，并作为缓冲层在连续充放电循环期间保持结构稳定性。石墨烯和C提高了VPO 4的导电性，并降低了充放电循环过程中的体积膨胀。当用作锂离子电池负极时，VPO4@C/石墨烯微球在100 mA g−1的电流密度下循环100次后，可以实现432.8 mA h g− 1的比容量。该性能上级商用石墨。VPO4@C/石墨烯微球提供了良好的倍率性能，在200、400、1000和2，000 mA g − 1下的容量分别为562.1、494、424.2和356 mAh g −1。此外，VPO4@C/石墨烯微球实现了> 1.2 g cm-3的高振实密度，高于其他纳米材料（< 1.0 g cm-3），并且与市售阳极材料相容。因此，VPO4@C/石墨烯微球是一种有前途的锂离子电池负极材料。
Three-dimensional PO4-based polyanionic structures composed of interconnected MO6octahedra and PO4tetrahedra, such as VPO4, are potential anode materials for Li-ion batteries given their excellent cyclic stability. However, the application of VPO4as an anode material has been limited by its low conductivity and drastic volume expansion. Herein, VPO4@C/graphene microspheres are designed and synthesised. P covalently bridges VPO4and graphene through P–C bonding and acts as a buffer layer to maintain structural stability during continuous charge–discharge cycling. Graphene and C improve the electrical conductivity of VPO4and reduce volume expansion during charge–discharge cycling. When applied as a Li-ion battery anode, the VPO4@C/graphene microspheres can achieve a specific capacity of 432.8 mA h g−1after 100 cycles under the current densities of 100 mA g−1. This performance is superior to that of commercial graphite. The VPO4@C/graphene microspheres provide a good rate performance with a capacity of 562.1, 494, 424.2 and 356 mAh g−1under 200, 400, 1000 and 2, 000 mA g−1, respectively. Furthermore, the VPO4@C/graphene microspheres achieve high tap density of > 1.2 g cm−3, which is higher than that of other nanomaterials (< 1.0 g cm−3) and is compatible with commercially available anode materials. Thus, VPO4@C/graphene microspheres are a promising anode material for Li-ion batteries.