Fabrication and properties of polybutadiene rubber-interpenetrating cross-linking poly(propylene carbonate) network as gel polymer electrolytes for lithium-ion battery

Abstract

Polybutadiene rubber-interpenetrating cross-linking poly(propylene carbonate) (named as XBRPC) membrane can be readily synthesized from polybutadiene rubber (BR), poly(propylene carbonate) (PPC), polyethylene glycol (PEG), and using benzoyl peroxide (BPO) as cross-linking agent, then activated by absorbing liquid electrolyte to fabricate a novel XBRPC gel polymer electrolyte (GPE) for lithium-ion battery. Electrolyte uptake, mechanical strength, ionic conductivity, electrochemical stability window and charge/discharge performances of the XBRPC membranes were then investigated. The results show that the XBRPC GPEs possess good mechanical strength and high electrolyte uptake. The ionic conductivity was up to 1.25 mS cm⁻¹ at room temperature and 3.51 mS cm⁻¹ at 80 °C for XBRPC70 (70/30 of PPC/BR, w/w) sample. Furthermore, the electrochemical stability window has been established to with stand voltages greater than 4.5 V. The results of charge/discharge tests show that the initial discharge capacity of Li/XBRPC70 GPE/LiFePO₄ cell is 119 mA h g⁻¹ at a current rate of 0.1C and in voltage range of 2.5–4.0 V at room temperature. It also exhibited excellent cycling retention performance for high-performance lithium rechargeable battery.