<br>用于高性能锂离子电池负极的石墨颗粒上分散良好的硅纳米颗粒上垂直石墨烯片的生长,Small

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用于高性能锂离子电池负极的石墨颗粒上分散良好的硅纳米颗粒上垂直石墨烯片的生长
Small ( IF 13.0 ) Pub Date : 2023-12-02 , DOI: 10.1002/smll.202307494
Peilun Yu _{1,

2} , Zhenwei Li _{1,

2} , Meisheng Han _{2,

3} , Jie Yu _{1,

2}

Affiliation

随着对高能量密度的需求迅速增长，硅（Si）因其高比容量而有望作为锂离子电池（LIB）负极材料发挥重要作用。然而，硅在充电过程中体积膨胀仍然是影响其循环稳定性的严重问题。据报道，垂直石墨烯片/硅/碳/石墨（VGSs@Si/C/G）的Si/C复合材料可以解决Si/石墨阳极的电化学稳定性问题，该复合材料是通过将Si纳米颗粒粘附在石墨颗粒上而制备的与壳聚糖，然后通过热化学气相沉积原位生长 VGS。作为一种有前途的负极材料，由于VGS的缓冲作用以及Si和石墨颗粒之间的紧密结合，该复合材料在1000次循环后可提供782.2 mAh g ^-1的高可逆容量，初始库伦效率为87.2%。此外，VGSs@Si/C/G 的扩散系数比没有生长 VGSs 的扩散系数高两个数量级。采用VGSs@Si/C/G负极和LiNi _0.8 Co _0.1 Mn _0.1 O ₂正极的全电池实现了343.6 Wh kg ⁻¹的高重量能量密度、500次循环后91.5%的高容量保持率和优异的平均CE 99.9%。

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Growth of Vertical Graphene Sheets on Silicon Nanoparticles Well-Dispersed on Graphite Particles for High-Performance Lithium-Ion Battery Anode

With rapidly increasing demand for high energy density, silicon (Si) is greatly expected to play an important role as the anode material of lithium-ion batteries (LIBs) due to its high specific capacity. However, large volume expansion for silicon during the charging process is still a serious problem influencing its cycling stability. Here, a Si/C composite of vertical graphene sheets/silicon/carbon/graphite (VGSs@Si/C/G) is reported to address the electrochemical stability issues of Si/graphite anodes, which is prepared by adhering Si nanoparticles on graphite particles with chitosan and then in situ growing VGSs by thermal chemical vapor deposition. As a promising anode material, due to the buffering effect of VGSs and tight bonding between Si and graphite particles, the composite delivers a high reversible capacity of 782.2 mAh g⁻¹ after 1000 cycles with an initial coulombic efficiency of 87.2%. Furthermore, the VGSs@Si/C/G shows a diffusion coefficient of two orders higher than that without growing the VGSs. The full battery using VGSs@Si/C/G anode and LiNi_0.8Co_0.1Mn_0.1O₂ cathode achieves a high gravimetric energy density of 343.6 Wh kg⁻¹, a high capacity retention of 91.5% after 500 cycles and an excellent average CE of 99.9%.

更新日期：2023-12-02

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