The ever-growing global population, energy scarcity issues, and climate change encourage scientists to explore eco-friendly and cost-effective energy sources. LIBs are recognized as one of the greatest effective means of storing clean energy sources in electrical power grids among the many forms of renewable energy resources. Regrettably, the large-scale commercialization of LIBs is a great challenge mostly owing to the lack of lithium on the earth. Emerging lithium-free batteries such as mono- and divalent metal ion batteries (NIBs, KIBs, Mg-ion batteries (MIBs), and Ca-ion batteries (CIBs)) can be suitable candidates for the existing LIB technology. With all their advantages such as high ionic conductivity and transference number, quick diffusion for NIBs and KIBs, and high volumetric and gravimetric capacities in CIBs and MIBs, these batteries are very reactive and show low mechanical stability during the charge–discharge process. Therefore, to aid readers in comparing the differences between lithium-free batteries and lithium metal batteries, this review aims to scrutinize the fundamental challenges related to the stability issues of electrode–electrolyte interphases (EEIs) in terms of chemistry and formation mechanisms to comprehend the origin of failures in lithium-free batteries. Moreover, the main instability issues in each part of these batteries and the recent design strategies exploited to improve their performance are discussed herein.
