Researchers develop multiphase 'Soggy Sand' electrolyte for high-temperature aqueous zinc metal batteries

Aqueous zinc metal batteries (AZMBs) are known for their high safety, low cost, and environmental friendliness. However, their practical application is hindered by hydrogen evolution corrosion at the zinc anode and the dissolution of cathode materials, which leads to battery swelling and performance decay. Besides, traditional aqueous electrolytes suffer from uncontrollable side reactions above 60 °C, which limits battery reliability.

In a study published in Nature Communications, a research team led by Prof. CHEN Zhongwei and Prof. WANG Dongdong from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences developed a multiphase aqueous "soggy sand" electrolyte (MASSE) which enhances interfacial stability and electrochemical reversibility of AZMBs at elevated temperatures, enabling stable operation of aqueous batteries in harsh thermal environments.

Researchers developed MASSE by using dual immobilization of diethylene glycol and aluminum oxide nanoparticles, which effectively restricts the activity of free water. The interactions among these multiphase components created a water-deficient solvent structure, endowing MASSE with exceptional thermal stability. Meanwhile, MASSE suppressed water-induced side reactions and promoted uniform zinc ion deposition/stripping even at elevated temperatures.

Researchers constructed a Zn||PANI full cell using MASSE, which operated over an ultra-wide temperature range from room temperature to 140 °C and had a lifespan of 1,700 cycles at a current density of 8 A g^-1. In addition, they constructed an aqueous zinc metal pouch cell which achieved over 100 stable cycles at 80 °C with infrared thermal imaging confirming uniform temperature distribution.

"MASSE provides an innovative electrolyte design strategy for next-generation energy storage systems which is capable of operating under harsh conditions," said Prof. CHEN.