Precise Proton Redistribution for Two‐Electron Redox in Aqueous Zinc/Manganese Dioxide Batteries

Abstract

The liquid electrolyte in conventional zinc/manganese dioxide (Zn/MnO2) batteries conduces to the capacity limitation of one‐electron redox from MnO2 to MnOOH, as well as undesired Mn loss with capacity deterioration. Herein, to conquer these challenges, a new idea is proposed on the precise proton redistribution in the hydrogel electrolyte for the preferred two‐electron redox reaction. Specifically, an acidic layer in the hydrogel adjoins the MnO2 cathode to maintain the two‐electron redox, a neutral layer adjoins the zinc anode to inhibit the dendrite growth, which is separated by a mildly alkaline layer to immobilize the proton distribution. The two‐electron redox of MnO2/Mn2+ and anode protection are demonstrated to play key roles in battery performance. Such a battery presents specific capacities of 516 mA h g−1 at 0.05 A g−1, as well as a capacity retention of 93.18% at 5 A g−1 after 5000 cycles without extra Mn2+ addition in the electrolyte. More importantly, fibrous Zn/MnO2 batteries using the tri‐layer electrolyte can sustain 2000 cycles with high initial capacity of 235 mAh g−1 at 1 A g−1. After 6000 times folding in 180°, it can maintain 99.54% capacity. When integrated into user's clothing or portable accessories, the fibrous battery is demonstrated as a great potential in wearable electronics.

Multi‐Component Crosslinked Hydrogel Electrolyte toward Dendrite‐Free Aqueous Zn Ion Batteries with High Temperature Adaptability

“…[4] Rechargeable aqueous ZIBs have gained widespread attention as an alternative candidate to LIBs owing to the usage of water as the electrolyte solvent, which can effectively decrease safety issues caused by flammable electrolyte. [5][6][7][8][9] In addition, Zn metal is often used as the anode of ZIBs owing to their inherent advantages such as high theoretical capacity of 820 mAh g −1 and low redox potential (−0.76 versus standard hydrogen electrode). [10] However, the severe dendrite growth in alkaline electrolyte can lead to the unavoidable short circuit and then capacity attenuation of ZIBs.…”

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

“…5b and c). 50,51 Similarly, O 1s was further characterized by XPS; in addition to the binding energy of the corresponding Mn–O in MnO 2 of 528.9 eV, there are also obvious signal peaks at 530.2 and 531.3 eV, assigned to the bond energy of C–O–C and CO in PEDOT (Fig. 5d), 52 this depth profile again established that PEDOT and DMO always coexist during the etching process.…”

A one-pot self-assembled AgNW aerogel electrode with ultra-high electric conductivity for intrinsically 500% super-stretchable high-performance Zn–Ag batteries

“…batteries, which has a signicant application advantage in exible and wearable electronics. 11,[13][14][15]19,30,34,37,43,[63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79] To further investigate the practical performances of the asfabricated ber-shaped Zn-Ag battery, a series of deformation tests were conducted (Fig. 4a).…”

“…batteries, which has a significant application advantage in flexible and wearable electronics. 11,13–15,19,30,34,37,43,63–79…”