Aqueous zinc batteries: Design principles toward organic cathodes for grid applications.

The development of low-cost and sustainable grid energy storage is urgently needed to accommodate the growing proportion of intermittent renewables in the global energy mix. Aqueous zinc-ion batteries are promising candidates to provide grid storage due to their inherent safety, scalability, and economic viability. Organic cathode materials are especially advantageous for use in zinc-ion batteries as they can be synthesized using scalable processes from inexpensive starting materials and have potential for biodegradation at their end of life. Strategies for designing organic cathode materials for rechargeable zinc-ion batteries targeting grid applications will be discussed in detail. Specifically, we emphasize the importance of cost analysis, synthetic simplicity, end-of-life scenarios, areal loading of active material, and long-term stability to materials design. We highlight the strengths and challenges of present zinc-organic research in the context of our design principles, and provide opportunities and considerations for future electrode design.