Preparation and characterization of polymer blend electrolyte membranes based on lithium acetate‐complexed carboxymethyl cellulose (<scp>CMC</scp>) and carboxymethyl chitosan (<scp>CMCh</scp>) blend

Abstract

Abstract This work aimed to prepare solid polymer blend electrolytes based on carboxymethyl cellulose (CMC) and carboxymethyl chitosan (CMCh) complexed with lithium acetate (LiCH 3 COO) for lithium‐ion batteries application. The solid polymer blend electrolytes of LiCH 3 COO‐complexed CMC/CMCh (50/50) polymer blend electrolyte were prepared by using the casting solution technique, where various weight percentages of LiCH 3 COO were mixed into CMC/CMCh (50/50) blend as host polymer. Solid polymer blend electrolytes of CMC/CMCh + 30wt% LiCH 3 COO had the highest ionic conductivity as much as 2.24 × 10 −5 S cm −1 among others. The CMC/CMCh blend (50/50) + 30wt% LiCH 3 COO degraded at temperature interval 256–473°C. Linear sweep voltammetry method shows that CMC/CMCh (50/50) + 30wt% LiCH 3 COO reached a decomposition voltage around 2.54 V, while CMC/CMCh (50/50) + 10wt% LiCH 3 COO was decomposed at a lower voltage around 1.55 V. Based on the transference number measurement appeared that the initial and final current values of 0.84 for the CMC/CMCh (50/50) + 30wt% LiCH 3 COO is higher than that of the CMC/CMCh (50/50) + 10wt% LiCH 3 COO (0.8). Based on the results obtained, it can be concluded that the CMC/CMCh blend (50/50) + 30wt% LiCH 3 COO meets the minimum requirements for the main parameters of ion conductivity and thermal stability as a solid electrolyte polymer membrane but needs improvement and attention to its mechanical properties. Highlights CMC and carboxymethyl chitosan (CMCh) have polar groups for ionic conduction. The CMC/CMCh blend (50/50) + 30wt% LiCH 3 COO has good ionic conductivity of 2.24 × 10 −5 S cm −1 . The CMC/CMCh blend (50/50) + 30wt% LiCH 3 COO has high thermal stability 256–473°C. The CMC/CMCh blend (50/50) + 30wt% LiCH 3 COO has high decomposition voltage around 2.54 V. The CMC/CMCh blend (50/50) + 30wt% LiCH 3 COO has higher transference number (0.84).