Enabling Extraordinary Rate Performance for Poorly Conductive Oxide Pseudocapacitors. Issue 3 (15th July 2020)

• Record Type: Journal Article
• Authors: Abdollahifar, Mozaffar; Liu, Hao‐Wen; Lin, Chia‐Hsin; Weng, Yu‐Ting; Sheu, Hwo‐Shuenn; Lee, Jyh‐Fu; Lu, Meng‐Lin; Liao, Yen‐Fa; Wu, Nae‐Lih; Agnese, Yohan Dall'
• Other Names: Zhang Chuanfang (John) guestEditor.
• Is Part Of: Energy & environmental materials. Volume 3:Issue 3(2020)
• Page Start: 405
• Page End: 413
• Publication Date: 2020-07-15
• Subjects: high‐rate performance -- pseudocapacitor electrodes -- single nanoparticles -- three‐phase contact point -- ultra‐long cycle life; Power resources -- Environmental aspects -- Periodicals; Renewable energy sources -- Periodicals; Environmental engineering -- Periodicals; 333.79
• DOI: 10.1002/eem2.12094
• Languages: English
• ISSNs: 2575-0356

Abstract

Abstract : Pseudocapacitive transition metal oxides (PTMOs) have the advantages of high areal capacitance and material density suitable for high‐energy supercapacitor devices, but they are typically marred by insufficient rate performance, which in turn deteriorates cyclic stability at high current levels. Using the example of spinel manganese oxide, herein we demonstrate that a pseudocapacitive oxide electrode of remarkable rate performance and cyclic stability may be realized by adopting oxide nanocrystallites, which are derived based on a novel solution chemistry, and carbon additive (CA) nanoparticles with highly uniform of size distributions. Precisely controlling the particle morphology and size distribution of the active material and conductive additive (CA) in the nanometer range can maximize the density of active material‐CA‐electrolyte three‐phase contact points, thus facilitating synchronized electron and cation flow for the completion of surface faradaic reactions. The resultant Mn3 O4 pseudocapacitive electrode exhibits rate capability and cycle stability, including 60% capacity retention at 60 A g −1 and no capacity fade over 100 000 cycles under dynamic current densities, far superior to the state‐of‐the‐art PTMO electrodes. The electrode design strategy is in general applicable to pseudocapacitors containing poorly conductive active materials. Abstract : A manganese oxide pseudocapacitive electrode with remarkable rate performance and cyclic stability is developed via a unique electrode structure that achieves a high density of oxide‐carbon‐electrolyte three‐phase contact points.