Super Long Lasting Zinc Ion Batteries Would be Great for Energy Storage | NextBigFuture.com

Researchers at the Technical University of Munich (TUM) have developed a new method that could extend the lifespan of aqueous zinc-ion batteries by several orders of magnitude. Instead of lasting just a few thousand cycles, they could now endure several hundred thousand charge and discharge cycles.

The main innovation is a special protective layer for the zinc anodes of the batteries. This layer addresses previous issues such as the growth of needle-like zinc structures—known as zinc dendrites—as well as unwanted chemical side reactions that trigger hydrogen formation and corrosion.

The research team, led by Prof. Roland A. Fischer, Chair of Inorganic and Metal-Organic Chemistry at the TUM School of Natural Sciences, uses a unique material for this purpose: a porous organic polymer called TpBD-2F. This material forms a stable, ultra-thin, and highly ordered film on the zinc anode, allowing zinc ions to flow efficiently through nano-channels while keeping water away from the anode.

Zinc-ion batteries with this new protective layer could replace lithium-ion batteries in large-scale energy storage applications, such as in combination with solar or wind power plants. They last longer, are safer, and zinc is both cheaper and more readily available than lithium.

Advanced Energy Materials – Ion-Transport Kinetics and Interface Stability Augmentation of Zinc Anodes Based on Fluorinated Covalent Organic Framework Thin Films

Zinc (Zn) emerges as an ideal anode for aqueous-based energy storage devices because of its safety, non-toxicity, and cost-effectiveness. However, the reversibility of zinc anodes is constrained by unchecked dendrite proliferation and parasitic side reactions. To minimize these adverse effects, a highly oriented, crystalline 2D porous fluorinated covalent organic framework (denoted as TpBD-2F) thin film is in situ synthesized on the Zn anode as a protective layer. The zincophilic and hydrophobic TpBD-2F provides numerous 1D fluorinated nanochannels, which facilitate the hopping/transfer of Zn2+ and repel H2O infiltration, thus regulating Zn2+ flux and inhibiting interfacial corrosion. The resulting TpBD-2F protective film enabled stable plating/stripping in symmetric cells for over 1200 h at 2 mA cm−2. Furthermore, assembled full cells (Zn-ion capacitors) deliver an ultra-long cycling life of over 100 000 cycles at a current density of 5 A g−1, outperforming nearly all reported porous crystalline materials.