Utilizing Cyclic Voltammetry to Understand the Energy Storage Mechanisms for Copper Oxide and its Graphene Oxide Hybrids as Lithium‐Ion Battery Anodes

Abstract

Graphene‐based materials have been extensively researched as a means improve the electrochemical performance of transition metal oxides in Li‐ion battery applications, however an understanding of the effect of the different synthesis routes, and the factors underlying the oft‐stated better performance of the hybrid materials (compared to the pure metal oxides) is not always demonstrated. For the first time, we report a range of synthetic routes to produce graphene oxide (GO)‐coated CuO, micro‐particle/GO “bundles” as well as nano‐particulates decorated on GO sheets to enable a comparison with CuO and its carbon‐coated analogue, as confirmed using scanning electron microscopy (SEM) imaging and Raman spectroscopy. Cyclic voltammetry was utilized to probe the lithiation/delithiation mechanism of CuO by scanning at successively decreasing vertex potentials, uncovering the importance of a full reduction to Cu metal on the reduction step. The GO hybrid materials clearly show enhanced specific capacities and cycling stabilities comparative to the CuO, with the most promising material achieving a capacity of 746 mAh g−1 and capacity retention of 92 % after 30 cycles, which is the highest stable capacity quoted in literature for CuO. The simple cyclic voltammetry technique used in this work could be implemented to help further understand any conversion‐type anode materials, in turn accelerating the research and industrial development of conversion anodes.

A Favorable Improvement in Reactivity between n-Al and Sheet-like Porous CuO as a Nanoenergetic Composite by Graphene Oxide Additives

“…The nine diffraction peaks appear in Figure a at 32.2°, 35.2°, 38.4°, 48.5°, 53.3°, 58.0°, 61.3°, 65.8°, and 67.8°, which can be indexed to the (−110), (002), (111), (−202), (020), (202), (−113), (022), and (113) plane inflection of tenorite CuO (JCPDS 48–1548). These results are consistent with those reported in the literature. ,− No other peak implies that the prepared sample is neat CuO after the calcination of the CuO precursor. Figure b displays the XRD curve of the n-Al/p-CuO/GO nanoenergetic composite (5 wt % GO) prepared by vacuum-assisted self-assembly.…”

Influence of LiNO3 on the Lithium Metal Deposition Behavior in Carbonate‐Based Liquid Electrolytes and on the Electrochemical Performance in Zero‐Excess Lithium Metal Batteries

“…The reduction peak at around 2.25 V versus Li|Li + contributes to the reduction of CuO present at the surface of the copper current collector. [ 54 ] Constant current experiments of Cu || Li cells, with and without LiNO 3 separator, at a current density of 0.05 mA cm −2 pointed out the reductive processes during the first electrodeposition on a copper current collector. Both cells show a similar voltage drop within the first 15 s, however, the cells with LiNO 3 modified separator show a small plateau around 1.8 V assigned to LiNO 3 reduction (Figure S5, Supporting Information).…”

Multiphysics Electrochemical Impedance Simulations of Complex Multiphase Graphite Electrodes

“…There are electrochemical characterization techniques widely employed to study battery electrodes such as potentiostatic intermittent titration (PITT), galvanostatic intermittent titration (GITT), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) . In this work, we place our focus on EIS.…”

“…While graphite's intrinsic properties are difficult to alter, improvement of the electrochemical performance of the graphite anode can still be achieved by microstructure designs. 13,14 There are electrochemical characterization techniques widely employed to study battery electrodes such as potentiostatic intermittent titration (PITT), 15 galvanostatic intermittent titration (GITT), 16 cyclic voltammetry (CV), 17 and electrochemical impedance spectroscopy (EIS). 18 In this work, we place our focus on EIS.…”