We develop a facile and low-cost method to construct porous N-doped carbon sheets wrapped MnO cubes with average size of 150 nm in 3D carbon networks by one-step pyrolysis strategy. The unique and novel nanostructure not only provides holes to promote fast ion transport and conductive framework to enhance the charge transfer, but also effectively supplies an elastic buffer space to accommodate volume expansion during cycling. Furthermore, kinetic analysis and other tests reveal that capacitive-controlled Li storage is a vital way and further oxidation of Mn²⁺ to a higher state with cycling contributes a lot of capacity. As a result, the composite electrode shows high specific capacity of 917 mAh g⁻¹ at 0.2 A g⁻¹ after 190 cycles, outstanding rate capability of 328 mAh g⁻¹ at 5 A g⁻¹, and long cycling stability (655 mAh g⁻¹ at 1 A g⁻¹ after 550 cycles, capacity retention of 105%). Furthermore, the composite electrode and LiFePO₄ are used as anode and cathode to assemble full cell which also exhibits excellent rate capability and cycling stability, indicating great application potential. The simple and low-cost strategy of synthetizing the unique nanocomposite structure can also be applied to other composite anode materials for lithium-ion batteries.

我们开发了一种简便且低成本的方法，通过一步热解策略在3D碳网络中构建包裹有MnO立方体的多孔N掺杂碳片，其平均尺寸为150 nm。独特而新颖的纳米结构不仅提供了促进快速离子迁移的孔和增强电荷转移的导电骨架，而且还有效地提供了弹性的缓冲空间以适应循环过程中的体积膨胀。此外，动力学分析和其他测试表明，电容控制的锂存储是一种至关重要的方法，并且随着循环的进一步将Mn ²⁺氧化成更高的状态，会产生很大的容量。其结果是，917毫安克复合电极显示出高的比容量^-1 在0.2 A克^-1190次循环后，在5 A g ^-1时具有328 mAh g ^-1的出色速率能力，并且具有长循环稳定性（550次循环后在1 A g ^-1时为655 mAh g ^-1，容量保持率为105％）。此外，复合电极和LiFePO ₄被用作阳极和阴极以组装整个电池，该电池还具有出色的倍率能力和循环稳定性，表明了巨大的应用潜力。合成独特的纳米复合结构的简单，低成本策略也可以应用于锂离子电池的其他复合负极材料。