In Situ Growth of 3D Lamellar Mn(OH)₂ on CuO-Coated Carbon Cloth for Flexible Asymmetric Supercapacitors with a High Working Voltage of 2.4 V

Abstract

Flexible asymmetric supercapacitor (FASC) systems are expected to exhibit not only excellent energy storage properties and safety but also satisfactory flexibility and robust integration. However, tremendous issues such as low capacitance, narrow voltage window, and poor mechanical properties still exist. In this paper, a novel kind of 3D lamellar Mn(OH) 2 nanosheets on Cu-plated carbon cloth with a core-shell integrated framework (CPCC@CuO@Mn(OH) 2 ) is fabricated to obtain the flexible material in the FASC. In this unique CPCC@CuO@Mn(OH) 2 electrode material, the high theoretical specific capacity of CuO and Mn(OH) 2 brings superior energy storage properties. Meanwhile, as the shell part, the deposited Mn(OH) 2 layer and coated CuO layer work as both capacity contributors and substrate protectors, simultaneously maintaining the high capacitance and satisfactory flexibility of the electrodes. Therefore, the capacitance successfully achieves around 8140 mF cm −2 under 0.5 mA cm −2 . Significantly, the assembled FASC (named as CPCC@CuO@Mn(OH) 2 //CC@AC) achieves a working voltage of up to 2.4 V. In the case of a high-power density close to 34.31 mW cm −3 , its energy density reaches around 6.29 mW h cm −3 . Moreover, the capacity holds 88.9% even after 10,000 cycles, showing its great application potential in the field of wearable electronics.

Emerging two-dimensional nanostructured manganese-based materials for electrochemical energy storage: recent advances, mechanisms, challenges, and prospects

“…12e and f, the GCD curves at 5 mA cm −2 are almost unchanged when the bending angle is 45, 90, and 135°, indicating that the SC has decent flexibility. 196 Unique Cu 2 O@Mn(OH) 2 core–shell hierarchical structures were prepared by using octahedral Cu 2 O as a template to support the growth of ultrathin Mn(OH) 2 nanoflakes (Fig. 12g).…”

“…(d-f) Reproduced with permission. 196 Copyright 2021, American Chemical Society. (g) A schematic illustration of the formation process of the Cu 2 O@Mn(OH) 2 core-shell structure.…”

“…As one of the transition metal hydroxides, Mn(OH) 2 is considered as a promising electrode material owing to its high specic capacitance, increased energy density, and high natural abundance. 195,196 However, Mn(OH) 2 materials are rarely studied for SCs, but broadly investigated as sacricial templates and manganese sources to obtain Mn-based related oxides and derived oxides with the target morphology. 197 Li and co-workers This journal is © The Royal Society of Chemistry 2022 synthesized ultrathin multilayer Mn(OH) 2 nanosheets.…”

“…(e) GCD curves at 5 mA cm −2 and different bending angles and (f) images. (d-f) Reproduced with permission 196. Copyright 2021, American Chemical Society.…”

Synthesis strategies of iron nitrides at carbon cloth as battery-like electrode for hybrid supercapacitors

“…Furthermore, carbon cloth, which is a crisscrossed interweaving structure of carbon threads that are composed of carbon fibers or nanofibers, is the most widely used current collector in the field of supercapacitors, particularly flexible supercapacitors (Chen et al, 2018). They increase the surface area of the electrodes and offer flexibility (Gong et al, 2021).…”