Hydrogen‐Free and Dendrite‐Free All‐Solid‐State Zn‐Ion Batteries

Abstract

An ionic‐liquid‐based Zn salt electrolyte is demonstrated to be an effective route to solve both the side‐reaction of the hydrogen evolution reaction (HER) and Zn‐dendrite growth in Zn‐ion batteries. The developed electrolyte enables hydrogen‐free, dendrite‐free Zn plating/stripping over 1500 h cycle (3000 cycles) at 2 mA cm–2 with nearly 100% coulombic efficiency. Meanwhile, the oxygen‐induced corrosion and passivation are also effectively suppressed. These features bring Zn‐ion batteries an unprecedented long lifespan over 40 000 cycles at 4 A g–1 and high voltage of 2.05 V with a cobalt hexacyanoferrate cathode. Furthermore, a 28.6 µm thick solid polymer electrolyte of a poly(vinylidene fluoride‐hexafluoropropylene) film filled with poly(ethylene oxide)/ionic‐liquid‐based Zn salt is constructed to build an all‐solid‐state Zn‐ion battery. The all‐solid‐state Zn‐ion batteries show excellent cycling performance of 30 000 cycles at 2 A g–1 at room temperature and withstand high temperature up to 70 °C, low temperature to –20 °C, as well as abuse test of bending deformation up to 150° for 100 cycles and eight times cutting. This is the first demonstration of an all‐solid‐state Zn‐ion battery based on a newly developed electrolyte, which meanwhile solves the deep‐seated hydrogen evolution and dendrite growth problem in traditional Zn‐ion batteries.

Electrochemical Zinc Ion Capacitors Enhanced by Redox Reactions of Porous Carbon Cathodes

“…Before self‐discharge test, the pouch cell was charged to 1.9 V for 1.830 h. After rested at open circuit for 10 days (240 h) (Figure 6d), the pouch cell was discharged to 0 V at the same current density of charge process for 1.706 h. Thus, the self‐discharge rate is calculated to be 0.028% per hour (Section S1.5, Supporting Information). The low self‐discharge rate of (Zn/PC)//PC pouch cell is competitive to the lead–acid batteries, [ 54,55 ] and much lower than the nickel‐based batteries, [ 56,57 ] the ZICs, [ 15,58 ] and the carbon‐based supercapacitors. [ 59,60 ] The high cycling stability and low self‐discharge rate of pouch cell certify that (Zn/PC)//PC ZIC is a promising energy storage device for practical applications.…”

An Interface‐Bridged Organic–Inorganic Layer that Suppresses Dendrite Formation and Side Reactions for Ultra‐Long‐Life Aqueous Zinc Metal Anodes

“…[21] To address the above issues,t he currently reported solutions can be divided into two aspects:s uppressing dendrite formation and minimizing side reactions.D endrite suppression can be achieved by introducing coating layers on Zn anode surface,which effectively modified the current and electrolyte flux on anode surface,s uch as CaCO 3 and SiO 2 layer, [22] porous active carbon layer and reduced graphene oxide (rGO) layer, [23,24] and so on. Furthermore,m any strategies have also been reported for relieving the side reactions beside suppressing dendrites,i ncluding coating az incophilic protective layer, [25] replacing ZnSO 4 with Zn-(CF 3 SO 3 ) 2 , [26] using electrolyte additives, [27][28][29] adoption of ah ighly concentrated zincic salt as electrolyte, [30] using modified conductive host, [31][32][33][34] employing single ion conduc-tive electrolyte, [35,36] alloying with Al, [37] adopting gel electrolyte or all solid electrolyte, [38][39][40] coating inorganic layer, [41][42][43][44] or organic (polyamide) layer. [45] Indeed, the side reactions and dendrite are very important issues for long life AZBs.…”

Rechargeable Aqueous Zinc‐Ion Batteries with Mild Electrolytes: A Comprehensive Review

“…[183] 2) Surface structures or high zincophilicity of some current collectors help the uniform and dense heterogeneous nucleation of Zn metals, which then further guide the subsequent Zn plating. [179] For ZIBs, the proposed current collectors include Cu, [253] Ti, [119,150,160,254] Ni, [255] stainless steel, [21,256] and a variety of carbon materials (carbon cloth/felt, [257,258] carbon fiber, [182,259] graphite paper [260,261] and graphene foam [67,192] etc).…”