(185o) PEO Based Composite Electrolytes Incorporating Lignocellulosic Nanofibrils for Solid-State Lithium-Ion Batteries

All-solid-state batteries with LiFePO₄ cathodes and polyethylene oxide (MW = 4,000,000) based electrolytes are optimized with polyethylene glycol dimethyl ether (MW = 1000) and lignocellulosic nanofibrils which are obtained from birch wood. Excellent electrochemical properties including improved ionic conductivity, good cycling stability and rate performance are achieved. Comparing with the electrolyte membranes consist of polyethylene oxide and LiClO₄, ambient temperature conductivities of the membranes adding polyethylene glycol dimethyl ether and lignocellulosic nanofibrils are improved by more than 10 times. Although the linear sweep voltammetry current presents more sensitive reactions to voltage, rate capacity and long time charge-discharge cycle test suggest reliable stability of these composite electrolytes. Scanning electron microscope, differential scanning calorimetry and infrared spectroscopies also indicate promising use of this composite electrolyte in solid-state lithium-ion batteries.