The stability and performance of lithium-oxygen batteries could be significantly improved with a tailored electrolyte that could represent the next generation of rechargeable batteries. This is according to a team of scientists from the University of Liverpool, Johnson Matthey PLC and Loughborough University, which has designed a new stable material mixture for lithium-metal anode lithium-oxygen batteries.
The lithium-oxygen (Li-O2) battery (or lithium-air battery), which consists of Li metal and a porous conductive skeleton as electrodes, releases energy from the reaction of oxygen in air with lithium. This emerging technology has a much higher energy storage potential than the conventional lithium-ion battery.
In a study published in the journal Advanced Functional Materials, Laurence Hardwick, Professor of Renewable Energy at the University of Liverpool, and colleagues have identified and developed electrolyte formulations that minimise side reactions and allow cycle stability.
According to the study’s lead author, Dr Alex Neale, a Hardwick fellow in Liverpool, the research shows that the reactivity of certain electrolyte components can be switched off by precisely controlling the ratio of the components. He explained, “The ability to accurately formulate the electrolyte using readily available, low volatility components has allowed us to specifically tailor an electrolyte to the needs of metal-air battery technology that has significantly improved cycle stability and functionality.”
“Li-O2 batteries have an extremely high theoretical specific energy, so the realisation of a practical and truly rechargeable Li-O2 device can outperform state-of-the-art lithium-ion cells at a fraction of the theoretical capacity. However, one of the main technological barriers to development is the stability of Li-O2 cell materials. If the stability and performance of Li-O2 batteries can be optimised, Li-O2 devices could significantly increase the range of electric aircraft, for example,” added Dr Pooja Goddard, from the Department of Chemistry at Loughborough University.
Much work remains to be done to improve the stability of the cathode materials, but the breakthrough represents a major milestone for the future of energy storage, as Li-O2 cells are expected to have up to ten times the charging capacity of current batteries.