A Solid-State Air Battery Could Be Safer, Longer-Lasting Than Today's Lithium-Based Alternatives
A clever design for a safer battery has been proven in the lab, though its longevity needs work before it'll offer real competition.
Researchers from the University of Yamanashi, Waseda University, and Osaka University have come up with a new completely solid-state air battery which, they say, could prove safer and longer-lasting than traditional lithium-ion liquid-electrolyte alternatives.
"To the best of my knowledge, no air batteries based on organic electrodes and solid polymer electrolyte have been developed yet," project lead Kenji Miyatake, professor, claims of the team's work. "This technology can extend the battery life of small electronic gadgets such as smartphones and eventually contribute to realizing a carbon-free society."
Where traditional lithium-ion and lithium-polymer batteries use solid electrodes in a liquid electrolyte, the team's air battery uses only solid components: a Nafion polymer electrolyte and a benzoquinone-based electrode. This, the researchers explain, makes it more robust — not puncture-proof without bursting into flames but also potentially surviving far more charge-discharge cycles.
As an air battery, the design pulls oxygen from the air to use as an active material in its positive electrode — an approach which offers high energy densities but which has previously required liquid electrolytes. Initially, its longevity was in question — dropping to 44 per cent after just 30 charge-discharge cycles — but the addition of Nafion, a copolymer discovered in the 1960s, to the negative electrode boosted this to 78 per cent.
A battery that only holds around three-quarters of its design capacity after 30 charges isn't much use, but the team is hopeful it can be dramatically improved. "While the present study proved the concept of the SSAB experimentally," the team admits, "its performance was still somewhat primitive. The instability of the oxygen-reducing diffusion electrode and the relatively high redox potential of the organic molecules are priority issues that we plan to address in our near-future agenda."
The researchers' work has been published under open-access terms in the journal Angewandte Chemie.