Temperature effects on the electrochemical behavior of graphite cathodes for aluminium-polymer batteries

This study assesses the performance of Aluminium-polymer batteries at variable temperatures between −20 °C and 80 °C. Pouch cells were constructed utilizing a solid polymer electrolyte (SPE) coupled with two different types of graphite cathode: mesocarbon microbeads (MCMB) and spherical graphite (SpG). Cyclic voltammetry and galvanostatic cycling with potential limitation measurements were conducted at different temperatures combined with variable current densities (from 25 mA/g to 100 mA/g). The results reveal that the resistance degradation below 0 °C is reversible, with performance being recovered when returning to positive temperatures. However, at moderately high temperatures above 60 °C, the degradation becomes permanent. MCMB cells operate effectively between –10 °C and 40 °C, while SpG cells function from 0 °C to 60 °C. The specific capacity of MCMB cells peaks at 20 °C at all current densities and then drops significantly at 60 °C. In contrast, SpG cells exhibit their highest capacities at 40 °C or 60 °C, followed by a rapid decline. The Coulombic efficiencies remain > 95 % from –20 °C to 40 °C for both types of cells but decrease progressively beyond these temperatures. The overall performance of both types of cells conveys that they are suitable for varying environmental conditions. • The MCMB cathode operates effectively between -10 °C and 40 °C. • The SpG cathode works well from 0 °C to 60 °C. • Irreversible cathode material degradation at elevated temperature ≥ 60 °C. • Negative temperatures < 0 °C allow performance recovery.