Effect of Si-Based Anode Lithiation on Charging Characteristics of All-Solid-State Lithium-Ion Battery

Abstract

The description of the design, manufacturing technology, and test results of thin-film solid-state lithium-ion batteries with a nanocomposite negative electrode Si@O@Al is given herein. This electrochemical system features the hike on the charging curve plateau, which is interpreted as the change from I–V of the Ti-Si@O@Al contact. The latter is due to the change in the type of silicon conductivity during lithiation, as a result of which the ohmic metal-semiconductor contact proves to be biased in the reverse direction, and the charging current is maintained by minority charge carriers. It is shown that the current-conducting component Si@O@Al is formed by a solid solution a-Si(Al), which has a p-type conductivity. The change in the type of conductivity occurs as a result of silicon compensation through lithiation. It was found that Si@O@Al is nonlinear conductor, which can be considered as a percolation cluster formed by amorphous silicon nanoparticles and molecular clusters of silicon dioxide. The height of the Schottky barrier of the Ti|a-Si(Al) contact and the electron affinity of the a-Si(Al) solid solution were estimated.