Challenges and industrial considerations towards stable and high-energy-density aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) maintain expectations in the field of clean and safe large-scale energy storage, but their industrial practicality remains a critical challenge. The efforts to pursue a single performance indicator in the laboratory, which are based on insufficient cathode loading, excessive Zn, and flooded electrolyte dosage, are far from meeting the demands of practical applications with harsh conditions, such as high cathodic areal capacity, a low N/P (negative capacity/positive capacity) ratio, a low E/C (electrolyte mass/capacity) ratio, and other industrial requirements. Therefore, in this review, we call for academic and industrial attention to these harsh conditions to truly address the energy density and stability challenges of AZIBs that meet industrial standards. Systematic guidance from laboratory cells to scalable soft-pack or pouch batteries in terms of high areal capacity, a low N/P ratio, and a low E/C ratio was analyzed. Particularly, the main challenges and factors from active and inactive components that affect the stability of pouch batteries under these harsh conditions were highlighted. We further discussed the differences between pouch batteries and industrial batteries from the viewpoint of industrial stability and production requirements. Finally, we proposed critical perspectives from industrial considerations to enable stable and high-energy-density AZIBs. This review provides a guidance from lab cells to industrial stable and high-energy-density pouch cells in terms of high areal capacity, a low negative capacity/positive capacity ratio, a low electrolyte mass/capacity ratio and industrial concerns.