Carboxymethyl cellulose organic gel polymer electrolyte enabling high performance of germanium-air batteries in a wide operating temperature range from? 10° C to?…
Abstract
Germanium (Ge)-air batteries have garnered substantial attention as a promising energy conversion system owing to their remarkable safety, high anode utilization, high theoretical chemical equivalent and high power density, and are expected to be used in portable electronic products such as electronic watches and hearing AIDS. However, traditional Ge-air batteries with liquid and gel electrolytes face challenges such as volatility, dehydration at high temperatures, and freezing at extremely low temperatures, which limit their operational lifespan and performance in extreme environments. In this study, a carboxymethyl cellulose (CMC) organic gel polymer electrolyte (CMC organic GPE) was synthesized through free radical polymerization and investigated its application in Ge-air batteries over a wide temperature range for the first time. The incorporation of CMC and dimethyl sulfoxide (DMSO) organic solvents reduced the crystallinity of GPEs, disrupted hydrogen bonding between water molecules, and minimized water loss, thereby enhancing the ionic conductivity of the electrolyte. Furthermore, the electrolyte exhibited excellent water retention and frost resistance. Ge-air batteries utilizing CMC organic GPEs not only provide an exceptional discharge life of 370?h at room temperature but also operated at low temperatures (?10 °C) and extremely high temperatures (80 °C). The optimized GPEs enabled the Ge-air battery to achieve a prolonged discharge life of 207?h at a high temperature of 70 °C and a current of 400?μA, as well as a peak power density of 1.37 mW cm?2 at 80 °C. This study offered novel opportunities for the exploration of Ge-air batteries that are suitable for extreme environments.