Aiming at the problems of poor temperature uniformity of lithium-ion batteries and high energy consumption of liquid cooling systems， a square lithium-ion battery was taken as the research object. Based on the verification of the battery cell model， a lithium-ion battery heat dissipation structure with a series-parallel symmetrical liquid cooling channel is designed. Five flow channel schemes are compared. Based on the fourth optimal scheme， the effects of the liquid cooling flow rate in the liquid cooling plate， the thickness combination of the aluminum plates， and the start-up time of the liquid cooling system on the battery heat dissipation and the energy consumption of the liquid cooling system are analyzed. The results show that compared with the channel shape S0 of scheme 1， the channel shape S3 of scheme 4 can reduce the maximum temperature difference of the cells in the battery module by 15%. In addition， the maximum temperature of the battery tends to decrease and then be gentle with the increase of the liquid cooling flow rate. Under the premise of ensuring the total mass of the liquid cooling system is unchanged， compared with the initial aluminum plate thickness combination h0， the adjusted aluminum plate thickness combination h4 can reduce the maximum temperature difference of the battery module by 12%. When the battery is discharged at 2.5C， the start-up time of the liquid cooling system is delayed to 563 s， which can ensure that the battery is within the best working temperature range and can save about 39% of the energy consumption cost of the liquid cooling system.