On the activation and charge transfer kinetics of evaporated silicon electrode/electrolyte interfaces

Silicon is a promising negative electrode material candidate for lithium-ion thin-film batteries because of its very high theoretical storage capacity. Assuming full conversion of Si into Li15Si4, a theoretical capacity of 3579 mAh g−1 or 8303 mAh cm−3 is expected. However, the interaction between silicon thin-film electrodes and various electrolytes (both liquid and solid) is, up until now, not well understood. The interface between the electrode and electrolyte plays a crucial role in the Li-(de)insertion reaction as here the actual charge transfer reaction takes places. To this end, some important issues on the activation of the electrode/electrolyte interface will be addressed in this paper. Moreover, new results on the temperature dependence of the charge transfer kinetics of evaporated silicon thin-film electrodes combined with four different liquid and solid electrolytes will be presented.