Solid State Zinc and Aluminum ion batteries: Challenges and Opportunities.

Solid‐state zinc ion batteries (ZIBs) and aluminum‐ion batteries (AIBs) are deemed as promising candidates for supplying power in wearable devices due to merits of low cost, high safety, and tunable flexibility. However, their wide‐scale practical application is limited by various challenges, down to the material level. This Review begins with elaboration of the root causes and their detrimental effect for four main limitations: electrode‐electrolyte interface contact, electrolyte ionic conductivity, mechanical strength, and electrochemical stability window of the electrolyte. Thereafter, various strategies to mitigate each of the described limitation are discussed along with future research direction perspectives. Finally, to estimate the viability of these technologies for wearable applications, economic‐performance metrics are compared against Li‐ion batteries. [ABSTRACT FROM AUTHOR]