Hierarchical Carbon Nanosheet Embedded MnO_x Cathode for High‐Performance Aqueous Zinc‐Ion Batteries

Abstract

Aqueous zinc‐ion battery is one of the candidates for the next generation batteries due to its reliable safety, environmental friendliness and low cost. While the poor structurally stability and limited cyclic reversibility of the cathode restricts its practical application. In this work, we elaborately design hierarchical three‐dimensional (3D) carbon networks (CNs) for the embedding of non‐stoichiometry MnOx with abundant defects (MnOx/CNs), which provide 3D diffusion pathway and efficient electrochemical active sites for zinc‐ion storage. The as‐designed Zn//MnOx/CNs battery delivers high energy density of 452.2 Wh kg−1 at a power density of 133.0 W kg−1, much superior to that of MnO2/CNs and pristine MnO2. Moreover, defective manganese species experience stable phase transformation during charging/discharging process, providing a long‐term cycling performance with a high reversible capacity of 263.3 mAh g−1 at 1 A g−1 after 1000 cycles.

Advanced MnOx/MnWO4 hetero-nanoflakes with abundant oxygen vacancies for high-performance flexible asymmetric supercapacitors with high energy density

“…The double hills are split at 641.8 and 652.79 eV belonging to the Mn 2p 3/2 and Mn 2p 1/2 orbital electrons of Mn 3+ , proving that Mn 4+ was partially reduced to Mn 3+ after thermal treatment and the introduction of oxygen vacancies. 27,28 According to the Mn 2p spectra, the ratio of Mn 3+ /Mn 4+ increased to 0.82 with the increase in the content of W dopants in MnO x /MnWO 4 @C-3 composites, implying the increasing relative number of oxygen vacancies. In addition, the higher content of Mo 3+ means the higher oxygen vacancy content.…”

“…3d shows the high-resolution O 1s spectra of MnO x /MnWO 4 @C-3 composites, which reveal three typical peaks at 530.87, 532.37 and 530.35 eV, representing lattice oxygen (O1), oxygen vacancy (O2) and oxygen species adsorbed on the surface (O3), respectively. 27,28 The proportion of oxygen vacancies in MnO x /MnWO 4 @C-3 is 0.25. However, the oxygen vacancies did not exist in the MnO x @C composites, which is in accordance with Fig.…”

Developments, Novel Concepts, and Challenges of Current Collectors: From Conventional Lithium Batteries to All‐Solid‐State Batteries

“…Novel materials such as MXene, metal‐organic framework (MOF), metal glass fibers (MGF) et al. with advantages of super‐lightweight, outstanding electrochemical stability, fire resistance, high strength, and flexibility, are good candidates for current collectors oriented toward advanced battery systems with high energy density [26,72–75] . Wang et al [72] .…”