Lithium Ion Battery Thermal Effect Research Of The Model

This article respectively to lithium iron phosphate batteries and the heating effect of the cobalt acid lithium battery model is studied.Lithium iron phosphate battery at different temperature(10 ℃ to 60 ℃)under the condition of heating,the heating effect of the battery can be divided into ohm heat Q_Ω,polarization heat Q_p,chemical reaction heat Q_r three parts respectively were studied.Through the analysis of the relationship between battery ohmic resistance and polarization resistance of the cell temperature and discharge rate of the galvanostatic intermittent titration and different temperature charge discharge experiments at different temperatures under different magnification,chemical reaction resistance with temperature relations,establish titration model.The contribution of positive and negative electrode and the combustion heat source of the battery to the battery.Theory with practice confirms the feasibility of the model.The AC impedance is obtained AC impedance cell under different temperature conditions,an equivalent circuit model,and through the analysis of least squares fitting software based on ZSimpWin,finally get the error in the impedance model 105 as following: LR(Q(R(LR))).The battery impedance model at different temperature(-10 ℃-60℃)based on the analysis on the electrothermal effect.Lithium iron phosphate battery titration model is achieved by pulse method,for its use in different temperature,discharge ratio under the condition of heating,high temperature of large discharge is irreversible damage to the battery.Battery performance under low temperature increase still remains to be improved.Cobalt acid lithium batteries by electrochemical impedance method to get the impedance model,low temperature cobalt acid lithium battery performance is superior to the lithium iron phosphate batteries,but as the temperature increase attenuation rate is,the temperature rise rate higher than that of lithium iron phosphate batteries,the security performance of the high temperature is low.High temperature battery safety performance and low attenuation degree needs to be improved.