Pseudocapacitive Charge Storage in Thick Composite MoS<sub>2sub> Nanocrystal-Based Electrodes
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- 作者：John B. Cook ; Hyung-Seok Kim ; Terri C. Lin ; Chun-Han Lai ; Bruce Dunn and Sarah H. Tolbert
- 刊名：Advanced Energy Materials
- 出版年：2017
- 出版时间：January 25, 2017
- 年：2017
- 卷：7
- 期：2
- 全文大小：3877K
- ISSN：1614-6840
文摘
A synthesis methodology is demonstrated to produce MoS<sub>2sub> nanoparticles with an expanded atomic lamellar structure that are ideal for Faradaic-based capacitive charge storage. While much of the work on MoS<sub>2sub> focuses on the high capacity conversion reaction, that process is prone to poor reversibility. The pseudocapacitive intercalation-based charge storage reaction of MoS<sub>2sub> is investigated, which is extremely fast and highly reversible. A major challenge in the field of pseudocapacitive-based energy storage is the development of thick electrodes from nanostructured materials that can sustain the fast inherent kinetics of the active nanocrystalline material. Here a composite electrode comprised of a poly(acrylic acid) binder, carbon fibers, and carbon black additives is utilized. These electrodes deliver a specific capacity of 90 mAh g<sup>−1sup> in less than 20 s and can be cycled 3000 times while retaining over 80% of the original capacity. Quantitative kinetic analysis indicates that over 80% of the charge storage in these MoS<sub>2sub> nanocrystals is pseudocapacitive. Asymmetric full cell devices utilizing a MoS<sub>2sub> nanocrystal-based electrode and an activated carbon electrode achieve a maximum power density of 5.3 kW kg<sup>−1sup> (with 6 Wh kg<sup>−1sup> energy density) and a maximum energy density of 37 Wh kg<sup>−1sup> (with 74 W kg<sup>−1sup>power density).