In order to improve the cooling efficiency and temperature consistency of the air-cooled prismatic battery module, a novel multicomponent phase change material-spring plate (MPCM-SP) was developed in this work. The MPCM was formed by combining lauric acid (LA), polyethylene glycol (PEG), palmitic acid (PA), and carboxylated multi-walled carbon nanotubes (MWCNT-COOH). The melting temperature of MPCM can be adjusted within the range 37 °C to 65 °C, and the associated latent heat of phase change varied from 159 J∙g−1 to 209 J∙g−1. The optimized proportions of LA, PEG, PA, and MWCNT-COOH achieved through multiple-objective optimization were 65.55 %, 7.07 %, 25.38 %, and 2.00 %, respectively. The cooling performance of the MPCM-SP was examined by experimental verification and numerical evaluation. The inclusion of MPCM-SP in the air-cooling system resulted in a reduction of 3.41 °C, 3.74 °C, and 3.32 °C in the maximum temperatures of the U-shaped, Z-shaped, and I-shaped battery modules, respectively. Moreover, the temperature difference was decreased by 3.60 °C, 3.16 °C, and 2.42 °C, respectively. Additionally, in comparison to a single battery, a battery equipped with MPCM-SP had a 32.8 % reduction in thermal deformation in the thickness direction under a thermal expansion coefficient of 4.06 × 10-6 K−1.