Researchers from Russia have synthesised and tested new polymer-based cathode materials for lithium dual-ion batteries.
The Russian team that includes Russia’s Skoltech Institute of Science and Technology, D. Mendeleev University, and the Institute of Problems of Chemical Physics of RAS demonstrated that polymer cathode materials can be used to create efficient lithium and potassium dual-ion batteries.
In some experiments the scientists used potassium electrolytes instead of lithium to obtain potassium dual-ion batteries.
The team synthesised two novel copolymers of dihydrophenazine with diphenylamine (PDPAPZ) and phenothiazine (PPTZPZ), which they used to produce cathodes. They used metallic lithium and potassium as anodes.
Lithium half-cells with PDPAPZ were more efficient, said the scientists due to its were quick cycling, good stability, retaining up to a third of its capacity after 25,000 operating cycles at an energy density of 398 Wh/kg.
The research was published in the journal Energy Technology.
Filipp A. Obrezkov, a Skoltech PhD student and the first author of the paper, said: “Our previous research addressed polymer cathodes for ultra-fast high-capacity batteries that can be charged and discharged in a few seconds, but we wanted more.
“We used various alternatives, including linear polymers, in which each monomeric unit bonds with two neighbours only.
“In this study, we went on to study new branched polymers where each unit bonds with at least three other units. Together they form large mesh structures that ensure faster kinetics of the electrode processes. Electrodes made of these materials display even higher charge and discharge rates.”