Researchers from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences (CAS) have been inspired by the way organisms tackle the ageing effects of highly reactive oxygen and free radicals to solve the problem of lithium battery electrolyte degradation.
For high-voltage lithium batteries, using layered transition-metal-oxide cathodes, the chemical degradation of the battery’s electrolytes results in rapid decay of its capacity, which poses substantial challenges to its practical applications.
The study was published in the Journal of the American Chemical Society on October 13.
The chemical degradation of the electrolytes in lithium batteries, with transition-metal oxides, is caused during the cycling of the circuit by oxidation and by an attack of free radicals— any atom, molecule, or ion with an unpaired valence (outer layer) electron.
Organisms often produce different types of enzymes that work to scavenge active oxygen and free radicals, to alleviate the degradation issue that occurs pretty much everywhere in nature— oxygen is one of the elements most capable of attracting electrons from other atoms and molecules.
Inspired by the anti-oxygen coping mechanisms of these organisms, the researchers developed a photostabiliser— adding a simple, anti-aging binder additive to the electrolyte to scavenge the oxygen atoms and free radicals as they occur.
Through theoretical calculation and experimental investigation, the researchers found that this bio-inspired oxygen scavenging mechanism delivered superior electrochemical performance, even under elevated temperatures.
Professor Cui, a lead researcher from QIBEBT, said: “This heralds a new paradigm for manipulating the cathode and electrolyte chemistry of all sorts of rechargeable batteries involving chemical degradation of electrolyte.”
