Impedance of a thin-film lithium-ion battery Si@O@Al|LiPON|LiCoO$_2$ at temperatures from -20$^\circ$C to +50$^\circ$C

The results on measuring the impedance of a solid-state thin-film lithium-ion battery of the Si@O@Al-LiPON-LiCoO$_2$ electrochemical system in the temperature range from -20$^\circ$C to +50$^\circ$C are presented. A structural model is proposed and the parameters of its elements, providing the best fit for the experimental Nyquist diagrams, are calculated. It is shown that the main contribution to the internal resistance is made by the LiPON–LiCoO$_2$ interface. Based on the temperature dependence of the LiPON solid electrolyte conductivity the activation energy of lithium is determined, which is in good agreement with the literature data.