Abstract The design of an unique micro/nanoscale structure and the composite construction with conductive materials are the two effective means to improve the electrochemical energy storage for transition metal oxides anode. However, the rational design and controllable synthesis of complex ternary transition metal oxide (such as CoMoO4) composite with polyhedron morphology is still a challenge. Herein, we report a facile and effective strategy to synthesize rhombic dodecahedron-like (denoted as RD-like) CoMoO4/C composite, which involves the initial pre-reaction between the newly made ZIF-67 with H2MoO4 in ethanol and the subsequent calcination for the resultant precursor powders in air. It is found that the calcination temperature plays a key role in determining the microstructures and the content of the generated activated carbon. Below 400 °C, the CoMoO4/C composite cannot be derived, whereas the perfect and regular RD morphology for CoMoO4/C composite also cannot be acquired over 500 °C. Moreover, a plausible mechanism for the construction of RD-like CoMoO4/C composite has also been proposed and explained. Benefiting from its unique structural merits and the significant synergistic effect of the in-situ composite activated carbon, the obtained RD-like CoMoO4/C composite at 500 °C displays outstanding electrochemical performances with high reversible capacity (532.5 mAh g−1/500th cycle at 1C), excellent cycling stability and better rate capability when it tested as anode materials for lithium-ion batteries. It is conceivable that this three-in-one strategy can be extended to design and construct other cobalt-based oxyacid/C composites with unique polyhedron morphology, and markedly boost their electrocehmical performaces.

中文翻译：

---

菱形十二面体状 CoMoO4/C 复合材料：锂离子电池的简易结构和优异的电化学性能

摘要 独特的微纳米结构设计和与导电材料的复合结构是提高过渡金属氧化物负极电化学储能的两种有效手段。然而，具有多面体形态的复杂三元过渡金属氧化物（如CoMoO4）复合材料的合理设计和可控合成仍然是一个挑战。在此，我们报告了一种合成菱形十二面体（表示为 RD 样）CoMoO4/C 复合材料的简便有效的策略，该复合材料涉及新制备的 ZIF-67 与乙醇中的 H2MoO4 之间的初始预反应以及随后的煅烧所得前体粉末在空气中。结果表明，煅烧温度在决定所生成活性炭的微观结构和含量方面起着关键作用。400℃以下，无法推导出 CoMoO4/C 复合材料，而在 500°C 以上也无法获得 CoMoO4/C 复合材料的完美和规则的 RD 形态。此外，还提出并解释了构建 RD 类 CoMoO4/C 复合材料的合理机制。受益于其独特的结构优点和原位复合活性炭的显着协同效应，所获得的 RD 类 CoMoO4/C 复合材料在 500°C 下表现出优异的电化学性能和高可逆容量（532.5 mAh g-1/500 次循环）在 1C)，当它作为锂离子电池的负极材料进行测试时，具有优异的循环稳定性和更好的倍率性能。可以想象，这种三合一策略可以扩展到设计和构建其他具有独特多面体形态的钴基含氧酸/C复合材料，