Achieving high rate and high energy density in an all-solid-state flexible asymmetric pseudocapacitor through the synergistic design of binder-free 3D ZnCo2O4 nano polyhedra and 2D layered Ti3C2Tx-MXenes. Issue 42 (14th October 2019)

• Record Type: Journal Article
• Authors: Javed, Muhammad Sufyan; Lei, Hang; Shah, Hidayat Ullah; Asim, Sumreen; Raza, Rizwan; Mai, Wenjie
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 42(2019)
• Page Start: 24543
• Page End: 24556
• Publication Date: 2019-10-14
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta08227a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Flexible ZCO‖MXene-ASC exhibits excellent electrochemical performance in a KOH/PVA hydrogel electrolyte with outstanding cycling stability in an enlarged potential window of 0.0–1.6 V with high flexibility. Abstract : Building flexible asymmetric supercapacitors (ASCs) with high-capacitance, high energy density and a super long life will contribute to the development of new energy storage devices in the future. Although ASCs possess a higher energy density than symmetric supercapacitors (SCs), however, lifespan is effectively degraded during the long-term cycling process. Herein, we demonstrate a high-performance all-solid-state flexible ASC based on battery-type bimetallic oxide (ZnCo2 O4 ) nano-polyhedra supported on carbon fibre textiles (ZCO@CFT) as the cathode and capacitive-type layer structured Ti3 C2 T x -MXene as the anode materials. Before assembling the ASC, both electrodes were systematically investigated in aqueous electrolyte and their performance optimized. The ZCO@CFT cathode exhibits high pseudocapacitive charge storage (∼63.22%) with a specific capacitance of 2643.66 F g −1 at 2 A g −1 and Ti3 C2 T x -MXene supported on carbon fibre textile (MXene@CFT) exhibits a high specific capacitance of 474.23 F g −1 at 1.5 A g −1 with remarkable cycling stabilities >95%. Furthermore, the ASCs were fabricated using ZCO@CFT as the cathode and MXene@CFT as the anode, (denoted as ZCO‖MXene-ASC) to check the feasibility of the proposed design. The ZCO‖MXene-ASC shows excellent energy storage properties by achieving a high capacitance of 281.25 F g −1 at 0.5 A g −1, a highly competitive energy density of 99.94 W h kg −1 at an admirable power density of 800 W kg −1 with a good life-time >94% over 5000 cycles and flexibility. According to the best of our knowledge, the achieved energy density of ZCO‖MXene-ASC is very competitive, and the highest among all binary metal oxides, carbonaceous materials, and MXene-based SCs and ASCs to date. Our concept of employing 3D bimetallic-oxides and 2D Ti3 C2 T x -MXene could open up a new direction in the development of high-performance flexible energy storage devices.