ZnCo_(2)O_(4)-ZnO@C@CoS核壳复合材料的制备及其在超级电容器中的应用

ZnCo_(2)O_(4)-ZnO@C@CoS Core-shell Composite:Preparation and Application in Supercapacitors

超级电容器以其高功率性能、稳定的循环性能和优良的安全性等独特优势,作为储能器件在新能源汽车和移动电子设备等方面极具前景。然而,其能量密度相对较低,限制了实际应用。为提升电化学活性,本研究通过简便的溶剂热法、煅烧处理和电化学沉积技术,在碳包覆的ZnCo_(2)O_(4)-ZnO微球上沉积了CoS纳米片(ZCO-ZO@C@CoS)。碳层不仅可以促进电子传输,增强导电性,还提升了结构的稳定性;CoS纳米片之间形成的开放网络空间促进了离子快速传输。此外,CoS纳米片具备丰富的电活性位点,实现了快速可逆的氧化还原反应;核壳结构内部的纳米线、碳层和外层纳米片的共同作用,有效提升了材料的整体电化学性能。因此,ZCO-ZO@C@CoS在1.5 A·g^(−1)时的比电容达到1944 F·g^(−1)(972.0 C·g^(−1)),20 A·g^(−1)高电流密度下循环10000次后比容量保持率为75%。由ZCO-ZO@C@CoS(正极)和活性炭(负极)组成的非对称超级电容器器件也表现出优异的比电容、高的倍率性能和优异的循环稳定性,显示出良好的应用前景。

Supercapacitors,distinguished by their unique advantages,including high power performance,stable cycling behavior,and excellent safety,emerge as highly promising energy storage devices in the fields of new energy vehicles and mobile electronic applications.However,the issue of relatively low energy density continues to constrain their practical applications.To enhance electrochemical activity,CoS nanosheets were deposited onto ZnCo_(2)O_(4)-ZnO microspheres coated with carbon(ZCO-ZO@C@CoS)using a facile solvothermal method,calcination treatment,and electrochemical deposition reaction.Carbon layer not only promoted electron transport to enhance electrical conductivity,but also improved the stability of the structure.The open network space formed between CoS nanosheets facilitated rapid ion transport.Additionally,CoS nanosheets possessed abundant electroactive sites,enabling rapid reversible redox reactions.The co-effect of nanowires of the core-shell structure,the carbon layer,and the outer nanosheets effectively enhanced the overall electrochemical performance.Consequently,ZCO-ZO@C@CoS exhibited a specific capacitance of 1944 F·g^(−1)(972.0 C·g^(−1))at 1.5 A·g^(−1),with an initial capacity retention of 75%after 10000 cycles at high current density of 20 A·g^(−1).The asymmetric supercapacitor device,comprising ZCO-ZO@C@CoS(positive electrode)and activated carbon(negative electrode),also demonstrated excellent specific capacitance,high-rate performance,and exceptional cycling stability,indicating significant potential for practical applications.