Manganese oxides hierarchical microspheres as cathode material for high-performance aqueous zinc-ion batteries

In situpolymerized synthesis of MnO nanoparticles anchored on N,S co-doped carbon as efficient cathodes for quasi-solid-state zinc ion batteries

“…61 The maximum specific power density is as high as 5330 W kg À1 , much higher than in pioneering studies. [52][53][54][55][56][57][58][59][60][61] Furthermore, our AZIBs possess long-term cycling stability at 2.67 A g À1 with a high coulombic efficiency of 100% (Fig. 5(h)).…”

“…5(g)). Our Zn‖MnO@NSC batteries deliver the maximum specific energy density of 474.7 W h kg −1 at a power density of 140 W kg −1 , better than that of AZIBs such as Zn‖α-MnO 2 (228.7 W h kg −1 at 287.3 W kg −1 ), 52 Zn‖GO-ZnMn 2 O 4 (140.7 W h kg −1 at 120.1 W kg −1 ), 53 Zn‖α-Mn 3 O 4 (252.9 W h kg −1 at 260.2 W kg −1 ), 54 Zn‖Mn 2 O 3 (176.5 W h kg −1 at 127.4 W kg −1 ), 55 Zn‖MnO 2 H 0.16 (H 2 O) 0.27 (330.3 W h kg −1 at 38.18 W kg −1 ), 56 Zn‖MnO (317.3 W h kg −1 at 126.2 W kg −1 ), 57 Zn‖β-MnO 2 (252.9 W h kg −1 at 260.2 W kg −1 ), 58 Zn‖todorokite (103.8 W h kg −1 at 107.7 W kg −1 ), 59 Zn‖Co 3 O 4 (83.1 W h kg −1 at 721.9 W kg −1 ) 60 and alkaline Ni‖Bi batteries (112.1 W h kg −1 at 109.7 W kg −1 ). 61 The maximum specific power density is as high as 5330 W kg −1 , much higher than in pioneering studies.…”

“…61 The maximum specific power density is as high as 5330 W kg −1 , much higher than in pioneering studies. 52–61…”

Synthesis and Performance Optimization of Manganese‐based Cathode Materials for Zinc‐Ion Batteries

“…Recently, we also synthesized δ-MnO 2 through the direct hydrothermal of KMnO 4 at 160 °C for 12 h. [55] α, β, δ-MnO 2 with the typical tunnel structure or layered structure are the main form of MnO 2 -based cathode in ZIBs. In contrast, limited by the specific capacity, there are fewer reports of other crystal types, such as λ-MnO 2 , [56] γ-MnO 2 , [57] etc. In short, diverse crystal types lead to the differences in electrochemical performance and energy storage mechanism.…”

An appropriate Zn2+/Mn2+concentration of the electrolyte enables superior performance of AZIBs

“…According to the previous reports, the generation of ZHS, which is formed as in eqn (3), is considered as the proof for the H + -insertion mechanism, in which the pH value increases near the H + -insertion sites, thus triggering the deposition of ZHS on the cathode. 42,43 Therefore, it could be speculated that the capacity of the MnO/0.5 M ZnSO 4 + 0.5 M MnSO 4 system is partially contributed by a H + -insertion process. This is in accordance with the morphology change of the cathode surface presented in Fig.…”