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• Self-discharge kinetics behavior of Li-Si anode is investigated by theoretical model and experiment. • Effective diffusion coefficients of soluble lithium in porous electrode are determined to verify the availability of model. • Effects of temperature, discharge current and electrode thickness on self-discharge kinetics behavior are discussed. • The three factors are coupled in the form of arrhenius equation by multivariate nonlinear regression. Self-discharge has significant influence on the service life of thermal batteries. The kinetics process of self-discharge depends on both the structure evolution and intrinsic property of electrodes. Herein, the kinetics model to quantify the self-discharge degree of the Li-Si anode is constructed according to the structure of thermal cells. Typical operation and preparation parameters, i.e. temperature, discharge current and electrode thickness, are evaluated based on the specially designed combined-discharge scheme. Then the effective diffusion coefficients (D eff) of soluble lithium (Li0) that are affected by the three variables are calculated and fitted. The calculation results consequently confirm self-discharge process of the Li-Si anode can be described by the derived equations exactly, and then the process is demonstrated to be diffusion-controlled. Further, D eff increase at the higher temperature and larger discharge current, while decrease with the increased electrode thickness, which is analyzed by scanning electron microscope and X-ray microcomputed tomography. The entire effects on D eff can be coupled in one fitting expression based on Arrhenius equation, and the apparent activation energies decrease under the larger discharge current and smaller electrode thickness. Finally, the additional experiments were conducted to verify the accuracy of the fitting expression. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a photoanode of compact TiO2 film with a small specific surface area has been developed to discuss the effects of interlayer in the dye/modification material alternating assembly structure. The compact film photoanode could avoid the complexity and various influence factors of porous film as light scattering and different diffusion rates of electrolyte in the pores. It is beneficial to discuss the effects of alternating assembly structure. From the discussion based on compact TiO2 film, it was indicated that the suitable material used for the interlayer of alternating assembly structure should show relatively strong alkalinity and higher energy level than the Lowest Unoccupied Molecular Orbital (LUMO) of dye molecules. The former is easier for the absorption of a second layer of dyes, and the latter ensured the generated electrons of the second layer of dye can inject into the conduction band of TiO2. Using the obtained suitable material as interlayer of alternating assembly structure enhanced the conversion efficiency of DSCs remarkably. [Copyright &y& Elsevier]