ABSTRACT
Novel electrolyte is being pursued toward exploring Zn chemistry in zinc ion batteries. Here, a fluorine-free liquid crystal (LC) ionomer-type zinc electrolyte is presented, achieving simultaneous regulated water activity and long-range ordering of conduction channels and SEI. Distinct from water network or local ordering in current advances, long-range ordering of layered water channels is realized. Via manipulating water activity, conductivities range from ≈0.34 to 15 mS cm-1 , and electrochemical window can be tuned from ≈2.3-4.3 V. The Zn|Zn symmetric cell with LC gel exhibits highly reversible Zn stripping/plating at 5 mA cm-2 and 5 mAh cm-2 for 800 h, with retained ordering of water channels. The capability of gel for inducing in situ formation of long-range ordered layer SEI associated with alkylbenzene sulfonate anion is uncovered. V2 O5 /Zn cell with the gel shows much improved cycling stability comparing to conventional zinc electrolytes, where the preserved structure of V2 O5 is associated with the efficiently stabilized Zn anode by the gel. Via long-range ordering-induced regulation on ion transport, electrochemical stability, and interfacial reaction, the development of LC electrolyte provides a pathway toward advancing aqueous rechargeable batteries.
ABSTRACT
The reversibility of metal anode is a fundamental challenge to the lifetime of rechargeable batteries. Though being widely employed in aqueous energy storage systems, metallic zinc suffers from dendrite formation that severely hinders its applications. Here we report texturing Zn as an effective way to address the issue of zinc dendrite. An in-plane oriented Zn texture with preferentially exposed (002) basal plane is demonstrated via a sulfonate anion-induced electrodeposition, noting no solid report on (002) textured Zn till now. Anion-induced reconstruction of zinc coordination is revealed to be responsible for the texture formation. Benchmarking against its (101) textured-counterpart by the conventional sulphate-based electrolyte, the Zn (002) texture enables highly reversible stripping/plating at a high current density of 10â mA cm-2 , showing its dendrite-free characteristics. The Zn (002) texture-based aqueous zinc battery exhibits excellent cycling stability. The developed anion texturing approach provides a pathway towards exploring zinc chemistry and prospering aqueous rechargeable batteries.
