Bifunctional sulfonated covalent polymers as modulator for oriented and highly reversible zinc plating during whole cycling process

This study is led by Prof. Xian-Xiang Zeng (School of Chemistry and Materials Science, Hunan Agricultural University) and Prof. Xiong-Wei Wu (School of Chemistry and Materials Science, Hunan Agricultural University).

The vast superiority in resource sustainability and volumetric energy density enables metallic zinc (Zn) to construct cost effective and environment-benign battery systems for the energy storage. However, the problems of Zn dendrites and poor Coulombic efficiency (CE) during cell’s whole life cycle stump its advancement as a rechargeable battery choice.  The solution is to modulate the Zn2+ desolvation prior to electro-reduction and subsequent deposition.

Herein, a transferred protection tactic via a bifunctional sulfonated covalent polymer interlayer is proposed to regulate the Zn²⁺ desolvation, which affects the formation of solid-electrolyte interphase, and guides its plating along with preferable (002) crystal plane. Protected by the sulfonated covalent polymers, the initial CE is elevated to an unprecedentedly high level (>96%) and quickly reaches a stable level >99%, and 570-h circulation is also realized at 2 mA cm⁻²/10 mAh cm⁻² in Zn||Zn cells. Besides, Zn||hydrated vanadium oxide-based full batteries with the low-concentration organic  electrolytes are also demonstrated with the high specific capacity of 173.8 mAh g⁻¹ at 0.5 A g⁻¹ and 64% capacity retention over 305 cycles and oriented Zn deposition.

See the article:

Bifunctional sulfonated covalent polymers as the modulator for oriented and highly reversible zinc plating

http://doi.org/10.1007/s11426-022-1464-6