In-Situ Solid Electrolyte Interface via Dual Reaction Strategy for Highly Reversible Zinc Anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• In situ construction of solid electrolyte interfaces (SEI) is vital for enhancing zinc (Zn) anode reversibility.
• Achieving high reversibility under high current densities (≥20 mA cm⁻²) for in situ SEI remains a significant challenge.

Purpose of the Study:

• To develop a novel in situ SEI construction strategy for high-performance zinc anodes.
• To investigate the dual role of the SEI as a "growth binder" and "orientation regulator" under varying current densities.

Main Methods:

• A dual reaction strategy involving spontaneous electrostatic reaction and electrochemical decomposition was employed for SEI formation.
• The SEI's layered structure (organic-rich upper, inorganic-rich inner) was characterized.
• Performance was evaluated using Zn//Zn symmetric cells and Zn//PANI pouch cells.

Main Results:

• The in situ SEI demonstrated exceptional stability and reversibility, cycling over 1300 h at 50 mA cm⁻² and 400 h at 100 mA cm⁻².
• Record-breaking cumulative capacity of 67.5 Ah cm⁻² was achieved.
• Effective suppression of side reactions and dendrite growth was observed.
• Practicality was validated in pouch cells with high mass loading (25.48 mg cm⁻²).

Conclusions:

• The proposed dual reaction strategy successfully constructs a robust, layered in situ SEI for zinc anodes.
• This advanced SEI significantly enhances reversibility and stability under high current densities, addressing a key challenge in zinc-ion batteries.
• The findings offer a universal approach for designing next-generation SEI layers for practical energy storage applications.