Investigation of an eco‐friendly polyacrylic acid binder system on LiFePO4 cathode electrode processing to enhance the performance of coin‐cell and pouch‐cell graphite||LiFePO4 batteries

Abstract This study investigates the influence of two types of binders (aqueous and nonaqueous) on the LiFePO 4 (LFP) electrode processing and its electrochemical properties. Specifically, polyvinylidene fluoride (PVDF) and polyacrylic acid (PAA) were dissolved in NMP ( N ‐methyl‐2‐pyrrolidone) or the aqueous solvent (H 2 O) at varying mass ratios of 5%, 10%, and 15%. Binder durability and inertness were assessed by immersing prepared LFP electrodes in an electrolyte comprising 1.0 M LiPF 6 in EC:DEC:DMC (1:1:1 in vol%). Notably, PVDF/NMP 10% and PAA/H 2 O 10%‐based electrodes displayed good durability without peeling. Electrochemical characteristics were evaluated through cycling voltammetry and galvanostatic cycling with potential limitation. The PAA/H 2 O 10%‐based‐LFP electrode exhibited a specific capacity of ~148.9 mAh g −1 with a Coulombic efficiency (CE) of around 97.27%, surpassing PVDF/NMP 10%. The graphite||PAA/H 2 O 10%‐based‐LFP electrode in a full cell demonstrated higher capacity and superior retention after 30 cycles. In a pouch cell (6 cm × 4 cm), utilizing graphite||LFP with PAA/H 2 O 10%, a capacity of 25.5 mAh was achieved, maintaining 93% capacity with a CE of about 99% after 30 cycles at a rate of 0.1C.