Analyses the temperature influence on lithium iron phosphate battery internal resistance characteristics

Source: 2020 - 04 - 11 18:48 hits: time, temperature on the characteristics of lithium iron phosphate battery internal resistance of lithium iron phosphate battery internal resistance is measured battery difficulty of ions and electrons in the conduction of main parameters, which directly determines the power of the battery characteristics, thus have great effect on the dynamic performance of electric vehicles. At the same time, the heat generated by the internal resistance also determines the battery. For example, in the classic Bemardi heat production model, the battery internal resistance is one of the key parameter to estimate the battery generate heat. Actual working environment temperature range of the electric car is opposite bigger, cell under different temperature and the working state of internal resistance is different also. Master, SOC and charge and discharge the battery internal resistance and temperature ratio and other internal relations, better thermal model for production, and management of heating system design based lil & # 39; 10 g power type lithium iron phosphate battery research, under the age of 25 and 40 ℃ temperature characteristic, the results show that as the temperature rise, battery charging and discharging process of the ohmic resistance, polarization resistance is reduced, and the ohm internal resistance under different temperature gradient were higher than polarization resistance rate, low ohmic resistance rate is greater than the high temperature ohmic resistance rate. Hong-yu guo et al. studied the power type lithium manganate battery internal resistance variation law under different ambient temperature ( f - 20 ~ 50℃) And SOC, through the experiment results show that the total battery internal resistance significantly changed at low temperature ( f0℃) And small SOC. Considering the electric cars need below 0 ℃ in winter under the environment of operation, the low temperature characteristics of the lithium iron phosphate battery internal resistance to fully study is very necessary. However, for the battery internal resistance characteristics under 0 ℃ research is few. This article USES the mixed method of pulse power characteristic ( HPPC) Test for 40 ah square energy lithium iron phosphate battery internal resistance under different temperature. At 20 ℃ to 40 ℃ was investigated under different temperature, the battery charge and discharge the battery internal resistance along with the change of the charged state. At 40 ah square electric cars with lithium iron phosphate batteries as the research object, the anode materials for lithium iron phosphate, unmodified, carbon. Anode material for high temperature in the phase of carbon microspheres ( MCMB1; Electrolyte for lithium electrolyte and organic solvent, diaphragm for polypropylene/polyethylene ( PP / PE) 。 The parameters of the single battery as shown in table 1. Battery charging and discharging equipment for Arbin EVTS power battery testing system. The incubator is Seth. Z - 040 l ultra-low temperature humidity chamber, constant temperature for battery charging and discharging experiments. Lithium iron phosphate battery parameters: x32xl80 size/( MMXMMXMM) : 100 minimum discharge voltage/V: 2. 5 maximum charging voltage/v: 3. Maximum charging current / 8 A: maximum discharge current / 160 A: 200 ( 1分钟) Working temperature ( Charge) / ℃ : 45 working temperature (0 ~ Traffic) /:- 20 ~ 45 rated voltage/v: 3. 2 power rating/ah: 40 quality/g: 1250