Abstract: General precise electrochemical battery model of Lithium-ion battery，Quasi-two-dimensional model，has two major numerical problems: excessive state quantities and high computational complexity，making it difficult to be applied in real time conditions． Aiming at the problems of quasi-two-dimensional model，a one-dimensional model is proposed． And the Laplace transform is used to transform the model into the frequency domain． The radial diffusion of solid-state lithium-ions is represented as a non-dimensional admittance form，which solves the problem of excessive state quantity by reducing the dimension． For the transcendental equation，the Padé approximation is used to reduce the computational complexity． The proposed model's complicity is analyzed and the model was verified by different discharging currents． The concentration distribution and terminal voltage of the proposed model and the exact model are compared． The experimental results show that a voltage error is within 40 mV，reducing the computational complexityunder and ensuring the accuracy of the model．

Key words: simplified 1D model;Padé, approximation,  electric vehicle, Lithium-ion battery, electrochemical model