The metal oxides/graphene composites are one of the most promising supercapacitors (SCs) electrode materials. However, rational synthesis of such electrode materials with controllable conductivity and electrochemical activity is the topical challenge for high‐performance SCs. Here, the Co₃O₄/graphene composite is taken as a typical example and develops a novel/universal one‐step laser irradiation method that overcomes all these challenges and obtains the oxygen‐vacancy abundant ultrafine Co₃O₄ nanoparticles/graphene (UCNG) composites with high SCs performance. First‐principles calculations show that the surface oxygen vacancies can facilitate the electrochemical charge transfer by creating midgap electronic states. The specific capacitance of the UCNG electrode reaches 978.1 F g⁻¹ (135.8 mA h g⁻¹) at the current densities of 1 A g⁻¹ and retains a high capacitance retention of 916.5 F g⁻¹ (127.3 mA h g⁻¹) even at current density up to 10 A g⁻¹, showing remarkable rate capability (more than 93.7% capacitance retention). Additionally, 99.3% of the initial capacitance is maintained after consecutive 20 000 cycles, demonstrating enhanced cycling stability. Moreover, this proposed laser‐assisted growth strategy is demonstrated to be universal for other metal oxide/graphene composites with tuned electrical conductivity and electrochemical activity.

中文翻译：

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氧空位丰富的超细Co3O4 /石墨烯复合材料，用于高速超级电容器电极

金属氧化物/石墨烯复合材料是最有前途的超级电容器（SCs）电极材料之一。然而，合理地合成具有可控电导率和电化学活性的此类电极材料是高性能SC的主要挑战。在此，以Co ₃ O ₄ /石墨烯复合材料为典型例子，开发出一种新颖/通用的一步激光辐照方法，克服了所有这些挑战，获得了富氧空位的超细Co ₃ O _4。具有高SC性能的纳米颗粒/石墨烯（UCNG）复合材料。第一性原理计算表明，表面氧空位可通过产生中间能隙电子态来促进电化学电荷转移。UCNG电极的比电容在1 A g ^-1的电流密度下达到978.1 F g ^-1（135.8 mA hg ^-1），甚至保持916.5 F g ^-1（127.3 mA hg ^-1）的高电容保持率在高达10 A g ^-1的电流密度下，显示出显着的速率能力（超过93.7％的电容保持率）。此外，连续2万次循环后，仍保持99.3％的初始电容，这表明循环稳定性得到了提高。此外，该拟议的激光辅助生长策略已被证明具有可调节的电导率和电化学活性，可用于其他金属氧化物/石墨烯复合材料。