Exploiting the synergistic effect of multiphase MnO₂ stabilized by an integrated conducting network for aqueous zinc-ion batteries

Abstract

δ-MnO2 is a typical oxide with large layered structure for rapid Zn-ion (Zn2+) accommodation capability and widely studied as cathode material in the aqueous Zn-ion batteries (ZIBs). However, structural instability...

In Situ Buildup of Zinc Anode Protection Films with Natural Protein Additives for High-Performance Zinc Battery Cycling

“…α-MnO 2 was synthesized according to previous research . Specifically, 2.94 g of Mn (CH 3 COO) 2 ·4H 2 O powder was distributed among 120 mL of DI water resulting in solution A.…”

“…α-MnO 2 was synthesized according to previous research. 41 Specifically, 2.94 g of Mn (CH 3 COO) 2 •4H 2 O powder was distributed among 120 mL of DI water resulting in solution A. In the meantime, 1.27 g of KMnO 4 was placed into 50 mL of DI water, resulting in solution B.…”

Metal–Organic Framework-Derived NiO@C as a Host for MnO2 Cathode of Stable Zinc-Ion Batteries

“…The enhanced performances were thought to be attributed to the synergistic effect between MnO 2 and NiO@C, which was similar to the roles of the Cu, Ni, and PEDOT additives for MnO 2 . 27,29,53 The conductive and porous NiO@C could likely facilitate the short ion diffusion, increase the conductivity of the electrode, and accelerate the electrochemical reaction kinetics for better capacity and rate performance. Unlike the CC/MnO 2 , galvanostatic charge and discharge (GCD) curves of the CC/ NiO@C/MnO 2 showed a linear capacity increase from 0.9 to 1.5 V, indicating the capacitive contribution from the NiO@C (Figure S7).…”

“…Aqueous zinc-ion battery (AZIB) potentially offers far less risk of fire and is cheaper than the present market-leading yet fire-prone lithium-based batteries. , However, bringing the AZIBs to market soon is less likely achievable, unless important challenges, such as intrinsic sluggish kinetics, severe structural collapse, poor rate performance, and large capacity fade, are specifically tackled. − Although some progress has been made so far, the lack of a suitable cathode to tolerate the stable insertion/extraction of Zn 2+ ions is still a challenge. , By far, only a few materials have been utilized as the Zn-intercalation hosts, which include Mn compounds, , V compounds, , Prussian blue analogue (PBA)-based compounds, , and other materials such as organics and Co- and Mo-based compounds. − Among these, MnO 2 has been widely studied as the cathode for AZIBs because of its merits like tunable morphologies, low cost, low toxicity, and high density. , Despite these advantages, MnO 2 (α-, β-, γ-, δ-, or amorphous MnO 2 ) generally exhibits high Mn dissolution, low intrinsic electronic conductivity, and large volume expansion caused by the phase transformations upon cycling. − Because these drawbacks seriously degrade the overall electrochemical performance (e.g., rapid capacity fading and poor rate capability), great efforts have been devoted to resolving this hurdle. , One emerging way is to deposit MnO 2 on the conductive host, thereby creating new composites such as MnO 2 /CNT(carbon nanotube), MnO 2 /graphene, , and MnO 2 /carbon. , Indeed, it has been experimentally demonstrated that MnO 2 hosted on porous carbon not only improves the rate performance but also triggers a significant capacity gain during battery cycling. − Moreover, it has been reported that the MnO 2 deposited on the host with binary or even multinary additives like Cu, Bi 2 O 3 , and PEDOT could also drastically improve the electrochemical performance of AZIB. − In this sense, metal–organic framework (MOF) is an appealing precursor for the preparation of the conductive host for MnO 2 cathode because MOF undergoes carbonization under simple pyrolysis, yielding a composite in the form of conductive graphitic carbon decorated with metal or metal oxide nanoparticles. , MOF-derived carbon materials generally have a 3D porou...…”

Tunable Vanadium Oxide Microflowers as High-Capacity Cathode Materials for Aqueous Rechargeable Zinc-Ion Batteries

“…Currently, to advance their commercialization, ARZIBs are urgently required to develop compatible cathode materials. ,, Unlike LIBs, the selection of cathode materials for ARZIBs is minimal owing to the strong electrostatic interactions between the divalent Zn 2+ ions and the ions of the cathode material . Hence, cathode materials for ARZIBs are mainly focused on three electrode families: manganese-based oxides (α-MnO 2 , − δ-MnO 2 , − β-MnO 2 , ,, γ-MnO 2 , , Mn 3 O 4 , , and ZnMnO 4 ), , vanadium-based oxides, ,− and Prussian blue analogues. − Manganese-based host materials suffer from capacity fading, poor intrinsic electrical conductivity, and complicated reaction kinetics. In contrast, Prussian blue analogue-based cathodes have a low-energy density because of their low theoretical capacity .…”