This study develops a 3D numerical model of the composite phase change materials (CPCM)‐flat heat pipe composite thermal management system and employs computational fluid dynamics to investigate its thermal performance under three‐cycle charge–discharge regimes (1C charge, 1C/3C/5C discharge), analyzing the impacts of CPCM mass and phase change temperature (PCT) to inform parameter optimization. Simulations reveal: at 1C, CPCM fails to attain the PCT, with battery temperature stabilizing at 35°C–39°C; at 5C, CPCM undergoes complete melting after the second cycle (maximum temperature: 76.70°C). All discharge rates exhibit excellent temperature uniformity (maximum temperature difference ≤1.93°C). For CPCM mass (density range: 863.88–1382.20 kg/m 3 ), increasing density to 1382.20 kg/m 3 at 5C results in a 5.67°C reduction in the maximum temperature during the third discharge compared to 1036.65 kg/m 3 , remaining within a reasonable range. With a fixed density of 1209.43 kg/m 3 , four PCTs (36.14°C/38.14°C/40.14°C/42.14°C) were evaluated: low PCTs provide short‐term thermal control benefits yet suffer from premature melting, degrading performance during prolonged 5C cycles; increasing PCT from 38.14°C to 42.14°C yields only a 2.16°C temperature drop. Thus, increasing CPCM mass is a viable optimization strategy (extending effective heat absorption duration and reducing battery temperature). PCT should be tailored to operating conditions—lower values for short cycles and moderately elevated values for long‐term cycles to balance thermal control efficacy and continuous operational capability.
Zhou et al. (Sun,) studied this question.