Kushwaha Vishal, Mandal K D, Gupta Asha, Singh Preetam
Department of Chemistry, Indian Institute of Technology (Banaras Hindu University) Varanasi, Uttar Pradesh, 221005, India.
Department of Ceramic Engineering, Indian Institute of Technology (Banaras Hindu University) Varanasi, Uttar Pradesh, 221005, India.
Dalton Trans. 2024 Mar 19;53(12):5435-5452. doi: 10.1039/d3dt04184k.
Grid-scale energy storage solutions are necessary for using renewable energy sources efficiently. A supercapattery (supercapacitor + battery) has recently been introduced as a new variety of hybrid devices that engage both capacitive and faradaic charge storage processes. Nano-chain architectures of NiCoS electrode materials consisting of interconnected nano-spheres are rationally constructed by tailoring the surface structure. Nano-chains of the bimetallic sulfide NiCoS are presented to have a superior charge storage capacity. The NiCoS nano-chain electrode presents a capacitance of 2001.6 F g at 1 mV s, with a specific capacity of 267 mA h g (1920 F g) at 1 A g in 4 M KOH aqueous electrolyte through the galvanostatic charge-discharge (GCD) method. The reason behind the high charge storage capacity of the materials is the predominant redox-mediated diffusion-controlled pseudocapacitive mechanism coupled with surface capacitance (electrosorption), as the surface (outer) and intercalative (inner) charges stored by the NiCoS electrodes are close to 46.0% and 54.0%, respectively. Additionally, a NiCoS//AC two electrode full cell operating in asymmetric supercapacitor cell (ASCs) mode in 4 M KOH electrolyte exhibits an impressive energy density equivalent to 257 W h kg and a power density of 0.73 kW kg at a current rate of 1 A g.
电网规模的储能解决方案对于高效利用可再生能源至关重要。最近，一种超级电容器（超级电容器+电池）作为一种新型混合设备被引入，它兼具电容性和法拉第电荷存储过程。通过调整表面结构，合理构建了由相互连接的纳米球组成的NiCoS电极材料的纳米链结构。研究表明，双金属硫化物NiCoS的纳米链具有卓越的电荷存储能力。通过恒电流充放电（GCD）方法，在4M KOH水溶液电解质中，NiCoS纳米链电极在1mV s时的电容为2001.6F g，在1A g时的比容量为267mA h g（1920F g）。材料具有高电荷存储容量的原因是，主要的氧化还原介导的扩散控制赝电容机制与表面电容（电吸附）相结合，因为NiCoS电极存储的表面（外部）电荷和嵌入（内部）电荷分别接近46.0%和54.0%。此外，在4M KOH电解质中以不对称超级电容器（ASC）模式运行的NiCoS//AC两电极全电池，在1A g的电流速率下，表现出令人印象深刻的能量密度，相当于257W h kg，功率密度为0.73kW kg。
