Flexible Three-Dimensional Heterostructured ZnO-Co₃O₄ on Carbon Cloth as Free-Standing Anode with Outstanding Li/Na Storage Performance

Abstract

Herein, a facile and binder-free method was developed to prepare a flexible electrode for dual battery applications, which was achieved by fabricating nanosheets of ZnO-Co 3 O 4 heterostructures attached on the surface of highly conductive carbon cloth (CC). Remarkably, for Li-ion batteries, the combined effects of two dimensional (2D) heterostructural and three dimensional (3D) carbon fiber substrate offered an excellent reversible capacity rate of approximately 1785 mAh g −1 at a current density of 200 mA g −1 .Even at a charge-discharge rate of 2000 mA g −1 , the ZnO-Co 3 O 4 @CC composite exhibited a reversible capacity of 491 mAh g −1 after 400 cycles. For sodium-ion batteries, the composite exhibited a reversible specific capacity of 684 mAh g −1 at a current density of 200 mA g −1 and a capacity of 265 mAh g −1 after 500 cycles at a current density of 1000 mA g −1 . Flexible half-cells were also constructed, which exhibited high flexibility and excellent electrochemical performance. The excellent performance is mainly due to the in situ growth of ZnO-Co 3 O 4 nanosheets on the CC, which provided a large contact area between the active material and the flexible and conductive substrate, ultimately facilitating rapid electron transport and preventing the aggregation of large surface area nanosheets.

Transition Metal Oxide Anodes for Electrochemical Energy Storage in Lithium‐ and Sodium‐Ion Batteries*

“…In another study, monodispersed hierarchical Co 3 O 4 spheres intertwined with carbon nanotubes, thus, forming a Co 3 O 4 @CNTs hybrid, showed good cycling performance and rate capability with a capacity of up to 230 and 184 mAh g −1 at 1600 and 3200 mA g −1 , respectively. [84] A binder-free hierarchical CoO active materials grown on carbon nanofibers (CNFs) has been synthesized by Jiang et al [85] They achieved an improved electrochemical performance by controlling the amount of CoO in the CNFs. However, the capacity remained rather low with 193 mAh g −1 at 50 mA g −1 after 50 cycles.…”

Polymer‐derived Co2Si@SiC/C/SiOC/SiO2/Co3O4 nanoparticles: Microstructural evolution and enhanced EM absorbing properties

“…The two strong peaks at 780.76 eV and 795.86 eV can be attributed to Co2p 1/2 and Co2p 3/2 , respectively. Furthermore, the peak binding energy (BE) at 777.9eV and 793.1eV can be assigned to Co 3+ , whereas the BE at 779.6 eV and 794.8 eV are assigned to Co 2+ , 32‐33 which nicely matches the Co‐O bond of Co 3 O 4 . It proves that Co 3 O 4 is obtained from the internal Co 2 Si/CoSi oxidation during the oxidation process.…”

“…It proves that Co 3 O 4 is obtained from the internal Co 2 Si/CoSi oxidation during the oxidation process. In addition, the BE at 783.8 eV and 801.7 eV can be associated with Co 2+ shakeup satellite peaks 32‐33 . Figure 5G shows the high‐resolution Si2p spectrum.…”

“…In addition, the BE at 783.8 eV and 801.7 eV can be associated with Co 2+ shakeup satellite peaks. [32][33] Figure 5G shows the high-resolution Si2p spectrum. The peaks at 100.9 eV, 101.8 eV, and 102.8 eV correspond to SiC, SiOC, and SiO 2 , respectively.…”

Recent Developments of Two-Dimensional Anode Materials and Their Composites in Lithium-Ion Batteries

“…And numerous materials have emerged for LIBs. − According to crystal structures and elemental compositions, 2D materials can be roughly divided into the following types: graphene, TMDs, TMOs, MXenes, and Xenes, as shown in Figure . These 2D nanomaterials have unique structures and properties, which can be widely applied in different fields of electronics. − Graphene is the most familiar 2D material with good electrical conductivity and high specific surface area (Figure ), which can provide high-capacity and -rate characteristics in LIBs. TMOs have abundant electrochemical reactivity sites and short lithium ions’ diffusion paths, but the single 2D nanosheet is prone to stacking and thus reducing the specific surface area of activity.…”