Effect of irreversible lithium plating at low temperature on the performance degradation of LiFePO4 lithium-ion batteries
During the low-temperature charging and discharging of lithium-ion batteries,lithium plating and stripping occur,with irreversible lithium plating leading to the formation of"dead lithium".This phenomenon adversely affects the battery's electrochemical performance.This study investigates the lithium plating-stripping behavior of commercial batteries,using LiFePO4 as the cathode and graphite as the anode,during 0.1C charge-discharge cycles at temperatures from 5 to-12℃ .A correlation between total and reversible lithium plating was established at different charging and discharging temperatures.Analysis of disassembled batteries,including negative electrode samples analyzed by SEM,EDX and XPS,revealed insights into the morphology,elemental distribution,and surface composition,clarifying the distribution of"dead lithium"on and within the negative electrodes.The study also assessed the impact of low-temperature charging and discharging on battery performance.It was found that the batteries'discharge capacities decreased following low-temperature cycling.At 0.5C,capacity degradation was more rapid after cycling at 5℃ compared to the primary battery,but slower at temperatures lower than 5℃ .We conclude that with lower temperatures increase both the total amount of lithium plating and the irreversible portion.The irreversible plating leads to a loss of active lithium,reducing capacity.However,at temperatures below 5℃,the increased loss of active lithium results in a lower negative electrode potential during lithiation,slowing the following capacity fading.The worse cycling performance at 5℃ is attributed to changes in the negative electrode's element distribution,pore structure,and surface composition.
lithium ion battery with the LiFePO4 cathodecharging and discharging at low temperatureirreversible lithium lossmorphology and element distribution within graphite electrodeperformance degradation
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