There is an urgent need to develop improved anode materials for lithium-ion batteries (LIBs). Herein, we report the synthesis of a graphene quantum dots (GQDs)-coated hierarchical nanoflake-based CuO microspheres (H–CuO) composite on copper foam via a one-pot hydrothermal technique for use as a binder-free anode for LIBs. The carboxyl-functionalized GQD coating on H–CuO not only results in lower charge-transfer resistance and enhanced electrical conductivity but also prevents the dissolution and agglomeration of the electrode. The GQDs/H–CuO composite anode exhibits a reversible capacity as high as 609 mAh g⁻¹ (pristine H–CuO: 61 mAh g⁻¹) after 200 cycles at 0.2 A g⁻¹. It also shows long-term cycling stability, exhibiting a capacity retention rate of 79.4% after 1000 cycles (pristine H–CuO: 0.7%) at a high current density (2 A g⁻¹) and improved initial coulombic efficiency at 88.2% (pristine H–CuO: 75.2%). The superior electrochemical properties of the GQDs/H–CuO composite anode are attributable to the graphene networks, which help maintain a high specific surface area and effectively protect the anodic active material from forming an unstable solid electrolyte interface layer. The proposed strategy for fabricating the GQD-coated metal oxide microsphere-based anode should contribute to the development of next-generation LIBs with improved electrochemical performance.

迫切需要开发改进的锂离子电池（LIBs）负极材料。在此，我们报告了通过一锅水热技术在泡沫铜上合成石墨烯量子点（GQDs）涂层的分层纳米薄片基 CuO 微球（H -CuO ）复合材料，用作 LIB 的无粘合剂阳极。H- CuO上的羧基功能化 GQD 涂层不仅可以降低电荷转移电阻和增强导电性，而且还可以防止电极的溶解和团聚。GQDs/ H -CuO 复合负极在 0.2 A g ^{-1 下}循环 200 次后表现出高达 609 mAh g ^-1的可逆容量（原始H -CuO：61 mAh g ^-1）. 它还显示出长期循环稳定性，在高电流密度（2 A g ^-1）下循环 1000 次后容量保持率为 79.4%（原始H -CuO：0.7%），初始库仑效率提高至 88.2%（原始H –CuO：75.2%）。GQDs/ H- CuO复合负极优异的电化学性能归功于石墨烯网络，有助于保持高比表面积并有效保护阳极活性材料不形成不稳定的固体电解质界面层。所提出的制备 GQD 涂层金属氧化物微球基阳极的策略应有助于开发具有改进电化学性能的下一代 LIB。