Solid-Adsorbed Polymer-Electrolyte Interphases for Stabilizing Metal Anodes in Aqueous Zn and Non-Aqueous Li Batteries

Polymers are known to adsorb spontaneously from liquid solutions in contact with high-energy substrates to form configurationally complex, but robust phases that often exhibit higher durability than might be expected from the individual physical bonds formed with the substrate. Rational control of the physical, chemical, and transport properties of such interphases has emerged as a fundamental opportunity for scientific and technological advances in energy storage technology but requires in-depth understanding of the conformation states and electrochemical effect of the adsorbed polymers. Here, we analyze the interfacial adsorption of oligomeric polyethylene glycol (PEG) chains of moderate sizes dissolved in protic and aprotic liquid electrolytes and find that there is an optimum polymer molecular weight of approximately 400 Da at which the highest columbic efficiency is achieved for both Zn and Li deposition. These findings point to a simple, versatile approach for extending the lifetime of batteries.

Automated summary

Polymers can spontaneously adsorb onto high-energy substrates from liquid solutions, forming configurationally complex and durable phases with higher durability than expected. Controlling the physical, chemical, and transport properties of these interphases is crucial for advancing energy storage technology. In this study, the interfacial adsorption of oligomeric polyethylene glycol (PEG) chains in different liquid electrolytes was analyzed, revealing an optimum polymer molecular weight of approximately 400 Da for achieving the highest columbic efficiency in both Zn and Li deposition. These findings provide a simple and versatile approach for extending battery lifetime.