A Functional Janus Ag Nanowires/Bacterial Cellulose Separator for High‐Performance Dendrite‐Free Zinc Anode Under Harsh Conditions

Abstract

Aqueous zinc‐ion batteries (AZIBs) offer promising prospects for large‐scale energy storage due to their inherent abundance and safety features. However, the growth of zinc dendrites remains a primary obstacle to the practical industrialization of AZIBs, especially under harsh conditions of high current densities and elevated temperatures. To address this issue, we developed a Janus separator with an exceptionally ultrathin thickness of 29 μm. This Janus separator features the bacterial cellulose (BC) layer on one side and Ag nanowires/bacterial cellulose (AgNWs/BC) layer on the other side. The high zincophilic property and excellent electric/thermal conductivity of AgNWs make them ideal for serving as an ion pump to accelerate Zn2+ transport in the electrolyte, resulting in the greatly improved Zn2+ conductivity, the deposition of homogeneous Zn nuclei, and dendrite‐free Zn. Consequently, the Zn||Zn symmetrical cells with the Janus separator exhibit a stable cycle life of over 1000 hours under 80 mA cm−2 and sustain over 600 hours at 10 mA cm−2 under 50°C. Furthermore, the Janus separator enables excellent cycling stability in AZIBs, aqueous zinc‐ion capacitors (AZICs), and scaled‐up flexible soft‐packaged batteries. Our study demonstrates the potential of functional separators in promoting the application of aqueous zinc batteries, particularly under harsh conditions.This article is protected by copyright. All rights reserved

Construction of Selective Ion Transport Polymer at Anode–Electrolyte Interface for Stable Aqueous Zinc-Ion Batteries

“…Consequently, the DA-PPy@Zn symmetric battery exhibits better rate performance (Figure c) and improved plating/stripping stability for over 1200 h under the test condition of 1 mA cm –2 and 1 mAh cm –2 (Figure d). Benefitting from the increasing t Zn 2+ and charge transfer at the interface (Figures S7 and S8), which could reduce the nucleation barrier, thus inducing intense and uniform nuclei sites; the DA-PPy@Zn electrode exhibits lower voltage polarization. ,, In addition, even at a harsh condition of 10 mA cm –2 and 5 mAh cm –2 , the DA-PPy@Zn symmetric battery shows a longer plating/stripping life of 300 h, compared to bare Zn (210 h) (Figure e). Notably, the nonuniform zinc deposition and the side reactions would be accelerated at “hot spots” at high temperature, which causes performance deterioration.…”

Functionalized Non-Glass Fiber Nanoporous Separator for High-Performance Aqueous Zinc Ion Batteries

“…Further improvements are needed in the electrochemical performance of modified cellulose separators under harsh conditions, including high current density and elevated temperatures. Cao et al 102 has introduced a groundbreaking ultrathin Janus separator, boasting a mere thickness of 29 μm. This innovative separator comprises a bacterial cellulose layer on one side and a layer of silver nanowires/bacterial cellulose (AgNWs/BC) on the other.…”

“…Cycling performances of Zn||Zn cells at (a) 50 °C and (b) room temperature. Reproduced with permission from ref . Copyright 2023 Wiley-VCH.…”

Double-sided engineering for space-confined reversible Zn anodes

“…5–11 Although tremendous progress has been reported, ZIBs with long-term stabilities are only obtained by using massive Zn anodes; thus it is still challenging to achieve high specific and volumetric energy densities for long-term practical applications. 12–17 Normally, ZIBs are constructed with significant excess of zinc anode ( e.g. 100 μm Zn foil, 58.5 mA h cm −2 ), where the Zn utilization rate is extremely low ( e.g.…”