Gel polymer electrolytes based on polyacrylate copolymer for energy storage

Lithium-ion batteries are the main source of energy for portable devices today and are becoming more deeply embedded in the transport sector every year. However, their energy density approaches a limit of 300 Wh/kg. Overcoming this limitation is possible if pure lithium is used as an anode material. A key obstacle to the widespread adoption of this technology is the problem of dendrite formation, which leads to short circuits, overheating, and explosions.

The formation of dendrites in batteries is caused by the accumulation of charge near the anode. To prevent dendrite formation, it is useful to covalently bond anions to the polymer matrix, which increases the transference number of cations and brings them closer to one.

Copolymers based on ion-conducting acrylates are promising materials due to their simple synthesis, low cost of monomers, and ability to vary the chemical composition. However, current research on these materials is fragmented, leading to gaps in our understanding of how the properties of these gels depend on their composition and structure.

In this study, we aim to conduct research on the relationships between the synthesis conditions, composition, and structure of gel polymer electrolytes based on acrylates, and their performance in lithium metal batteries.

The polymer was obtained through thermal polymerization initiated by benzoyl peroxide. Polymerization was carried out under vacuum to prevent atmospheric water from interfering with the process. The resulting polymer membrane was then flooded with a mixture of ethylene carbonate, propylene carbonate, and LiPF₆.

Impedance spectroscopy showed that the ionic conductivity of this particular polymer electrolyte was 0.58 mS/cm, comparable to other promising electrolytes. The lithium transference number was determined using the Bruce–Vincent method. A value of 0.58 for the cation transference number indicated the predominant transport of cations, suggesting a potential solution to the problem of dendrite formation.