Battery (electricity)

Quantum mechanics

Engineering

Biology

Electrochemistry

Materials science

Interphase

Power (physics)

Inorganic chemistry

Chemical engineering

Physical chemistry

Genetics

Physics

Organic chemistry

Aqueous solution

Chemistry

Electrode

Anode

Electrolyte

Fast ion conductor

Advanced Materials

Rechargeable aqueous Zn-ion batteries promise high capacity, low cost, high safety, and sustainability for large-scale energy storage. The Zn metal anode, however, suffers from the dendrite growth and side reactions that are mainly due to the absence of an appropriate solid electrolyte interphase (SEI) layer. Herein, the in situ formation of a dense, stable, and highly Zn2+-conductive SEI layer (hopeite) in aqueous Zn chemistry is demonstrated, by introducing Zn(H2PO4)2 salt into the electrolyte. The hopeite SEI (≈140 nm thickness) enables uniform and rapid Zn-ion transport kinetics for dendrite-free Zn deposition, and restrains the side reactions via isolating active Zn from the bulk electrolyte. Under practical testing conditions with an ultrathin Zn anode (10 µm), a low negative/positive capacity ratio (≈2.3), and a lean electrolyte (9 µL mAh−1), the Zn/V2O5 full cell retains 94.4% of its original capacity after 500 cycles. This work provides a simple yet practical solution to high-performance aqueous battery technology via building in situ SEI layers.

Electrolyte Design for In Situ Construction of Highly Zn <sup>2+</sup> ‐Conductive Solid Electrolyte Interphase to Enable High‐Performance Aqueous Zn‐Ion Batteries under Practical Conditions

Electrolyte Design for In Situ Construction of Highly Zn 2+ ‐Conductive Solid Electrolyte Interphase to Enable High‐Performance Aqueous Zn‐Ion Batteries under Practical Conditions

Electrolyte Design for In Situ Construction of Highly Zn ²⁺ ‐Conductive Solid Electrolyte Interphase to Enable High‐Performance Aqueous Zn‐Ion Batteries under Practical Conditions