Fabrication and Characterization of Plasma Sprayed TiO2 and Li4Ti5O12 Materials as All Active Material Lithium-Ion Battery Electrodes

Abstract

Two strategies to increase battery energy density at the cell level are to increase electrode thickness and to reduce the amount of inactive electrode constituents. All active material (AAM) electrodes provide a route to achieve both of those aims toward high areal capacity electrodes. AAM electrodes are often fabricated using hydraulic compression processes followed by thermal treatment; however, additive manufacturing routes could provide opportunities for more time-efficient and geometry-flexible electrode fabrication. One possible route for additive manufacturing of AAM electrodes would be to employ plasma spray as a direct additive manufacturing technology, and AAM electrode fabrication using plasma spray will be the focus of the work herein. TiO2 and Li4Ti5O12 (LTO) powders were deposited onto stainless steel substrates via plasma spray processing to produce AAM battery electrodes, and evaluated with regards to material and electrochemical properties. The TiO2 electrodes delivered low electrochemical capacity, <12 mAh g−1, which was attributed to limitations of the initial feed powder. LTO plasma sprayed AAM electrodes had much higher capacity and were comparable in total capacity at a low rate of discharge to composite electrodes fabricated using the same raw powder feed material. LTO material and electrochemical properties were sensitive to the plasma spray conditions, suggesting that tuning the material microstructure and electrochemical properties is possible by controlling the plasma spray deposition parameters.