Abstract Urchin-like NiCo2O4/stereotaxically constructed graphene (t-SCG) microspheres are synthesized via a hydrothermal method. NiCo2O4/t-SCG microspheres display hierarchical porous structures with large specific surface area (138.81 m2 g−1). When evaluated as anode materials for Li-ion battery, NiCo2O4/t-SCG electrode shows a high reversible specific discharge capacity of 498.5 mA h g−1 even in the 200th cycle at a current density of 0.5 A g−1. The performance of the sample as anode materials for Na-ion battery is also evaluated. NiCo2O4/t-SCG electrode can deliver a high initial specific discharge capacity of 818.9 mA h g−1, stable cycling with more than 314 mA h g−1 at 0.1 A g−1 in the 50th cycle. Compared with bare NiCo2O4 microspheres, NiCo2O4/t-SCG microspheres show much higher capacities and stability for both Li- and Na-ion battery, attributed that t-SCG acts as an efficient 3D conductive network to improve electronic conductivity.

中文翻译：

---

水热合成海胆状NiCo2O4/立体结构石墨烯微球用于超高速率锂和钠存储

摘要 通过水热法合成了类似海胆的 NiCo2O4/立体定向构建的石墨烯 (t-SCG) 微球。NiCo2O4/t-SCG 微球显示出具有大比表面积 (138.81 m2 g-1) 的分级多孔结构。当作为锂离子电池的负极材料进行评估时，NiCo2O4/t-SCG 电极即使在 0.5 A g-1 的电流密度下在第 200 次循环中也表现出 498.5 mA h g-1 的高可逆比放电容量。还评估了样品作为钠离子电池负极材料的性能。NiCo2O4/t-SCG 电极可以提供 818.9 mA h g-1 的高初始比放电容量，在第 50 次循环中以 0.1 A g-1 稳定循环超过 314 mA h g-1。与裸 NiCo2O4 微球相比，NiCo2O4/t-SCG 微球对锂离子和钠离子电池显示出更高的容量和稳定性，