Sustainable Lithium-Ion Battery Separator Membranes Based on Carrageenan Biopolymer

Aiming to improve the sustainability of materials for lithium-ion batteries (LIBs), this work reports on the development of novel membranes based on iota-carrageenan biopolymer and their suitability as separator in LIBs applications. The membranes are prepared by freeze-drying and its morphology, thermal, mechanical, and electrochemical properties are evaluated as a function of polymer concentration in the solution. Porous membranes with a degree of porosity above 90% and different interconnected pore sizes between 50 and 70 mu m for both polymer concentrations are obtained. The electrochemical parameters of the membranes are influenced by the carrageenan polymer concentration, being 1.34 mS cm(-1), 3, 7, and 0.48 for ionic conductivity, tortuosity, MacMullin number, and lithium transference number, respectively, for the membrane prepared from the 4 wt% carrageenan content solution. The half-cells cathodic prepared with the developed membranes show good cyclability and rate capability. The discharge capacity values obtained with the membrane prepared from 4 wt% carrageenan content are 145 and 25 mAh g(-1) at C/10- and 1C-rates, respectively, demonstrating excellent battery cycling performance and long-term stability. Thus, this work demonstrates that iota-carrageenan biopolymer membranes developed by freeze-drying can be used as separators for a next generation of more sustainable batteries.

Automated summary

This work reports the development of novel membranes based on iota-carrageenan biopolymer for lithium-ion batteries (LIBs) applications. The membranes exhibit excellent porosity and electrochemical properties, leading to improved battery cycling performance and stability.