Facile Self-Assembly Solvothermal Preparation of CuO/Cu₂O/Coal-Based Reduced Graphene Oxide Nanosheet Composites as an Anode for High-Performance Lithium-Ion Batteries

Abstract

Copper oxide is considered as a potential anode material for lithium-ion batteries (LIBs), which have attracted huge amounts of research ardor owning to the high capacity and ultrahigh theoretical capacity, twice that of a graphite anode. However, the practical application of the copper oxide anodes is hindered by their inherent properties, including low conductivity and huge volume variation of active materials during the lithiation reaction. Consequently, a novel CuO/Cu 2 O/coal-based reduced graphene oxide nanosheet composite (CCO/CRGO) with porous structure and conductive network was constructed via a mild solvothermal self-assembly method. Thanks to the unique structure, which facilitates the electronic transference and ion diffusion while also easing the volume expansion of copper oxides, the obtained CCO/CRGO anode exhibits a higher reversible capacity of 586 mAh g −1 at 1 A g −1 with impressive stability, and the capacity restored to 767 mAh g −1 when the current density reduced to 0.1 A g −1 . Electrochemical kinetic analysis of CCO/CRGO indicates that the capacitive contribution is the most of the capacity stems, which can improve the rate performance of the CCO/CRGO electrode. Considering the desirable electrochemical performance and the simple synthesis route, CCO/CRGO may be a candidate when used as an anode material for high-rate LIBs.

The Synergetic Effect Induced High Electrochemical Performance of CuO/Cu2O/Cu Nanocomposites as Lithium-Ion Battery Anodes

“…The Coulombic efficiency increased to 98% in the second cycle and was maintained near 100% in the following cycles. Furthermore, the reversible capacity of 1,265.7 mAh/g after 200 cycles was obtained, which is the highest of all reported results as far as we know (Huang et al, 2011;Mai et al, 2011;Shen et al, 2013;Zhang et al, 2013;Wang et al, 2014a;Wang et al, 2014b;Zhou et al, 2014;Chen et al, 2015;Xu et al, 2015;Ananya et al, 2016;Shi et al, 2016;Xu et al, 2016;Yuan et al, 2017;Wu et al, 2018;Kim et al, 2019;Xu et al, 2019;Yuan et al, 2019;Pan et al, 2020;Trukawka et al, 2021;Zhang et al, 2021). The jumps in the cycle curves at the 155th and 65th cycles for CuO nanowires and CuO/Cu 2 O/Cu nanocomposites were caused by the interruption of electrical power.…”

“…x O 1−x/2 (0 ≤ x ≤ 0.4) solid-solution mixed-phase (Huang et al, 2011;Yuan et al, 2019;Zhang et al, 2021), formation of Cu 2 O phase (Zhang et al, 2013;Wu et al, 2018;Zhang et al, 2021), and the following transformation into Cu phase as well as the formation of solid electrolyte interface (SEI) (Shi et al, 2016;Yuan et al, 2017;Li et al, 2021c). The three reduction peaks increase to 2.34, 1.32, and 0.83 V and overlap in the following cycles (Xu et al, 2019), which indicates the excellent reversible cycle stability (Huang et al, 2011;Chen et al, 2015;Shi et al, 2016;Yuan et al, 2017;Trukawka et al, 2021).…”

“…Rechargeable Lithium-ion batteries (LIBs) have been widely used in many fields, such as electric vehicles, cameras, and other portable electronic devices, because of their high working potential, lack of memory effect, and high energy density Hu et al, 2020;Teng et al, 2020;Zhang et al, 2020;Zuo and Gong, 2020;Li et al, 2021;Wang et al, 2021;Li et al, 2021;Li et al, 2021d;Wu et al, 2021;Liang et al, 2022). However, the traditional graphite anodes cannot meet further demands of high-power hybrid electric vehicles in the future because of the relatively inferior rate performance and the low theoretical capacity (372 mAh/g) (Shen et al, 2013;Zhang et al, 2013;Zhou et al, 2014;Pan et al, 2020;Wang et al, 2021).…”

“…To solve these problems, many different kinds of nanostructures and morphologies were designed and prepared by many kinds of methods (Wang et al, 2014;Wang et al, 2014;Xu et al, 2016;Kim et al, 2019;Yuan et al, 2019;Zhang et al, 2021). Zhang et al (2013) synthesized porous CuO nanosphere film which was used as anodes, exhibiting a high reversible discharge capacity of 799.7 mAh/g.…”

“…The transition metal oxides have been widely researched for their low cost, widespread availability, and high theoretical capacities (500–1,000 mAh/g) ( Shen et al, 2013 ; Zhang et al, 2013 ; Zhou et al, 2014 ; Ananya et al, 2016 ; Pan et al, 2020 ). Especially, copper-based oxides were paid much more attention owing to their abundance, environment-friendly, superior rate performance, and high theoretical capacities (674 mAh/g for CuO and 375 mAh/g for Cu 2 O) ( Shen et al, 2013 ; Zhang et al, 2013 ; Wang et al, 2014 ; Zhou et al, 2014 ; Ananya et al, 2016 ; Kim et al, 2019 ; Pan et al, 2020 ; Zhang et al, 2021 ). However, there are also some intrinsic disadvantages, such as volume expansion and low electric conductivity during the charge-discharge process, which should be resolved ( Shen et al, 2013 ; Zhang et al, 2013 ; Zhou et al, 2014 ; Ananya et al, 2016 ; Pan et al, 2020 ).…”