Cold sintering process for fabrication of a high volumetric capacity Li₄Ti₅O₁₂ anode

The cold sintering process (CSP) is useful for densifying lithium ion battery composite electrodes to achieve higher volumetric capacity density. Lithium titanate is one of the most promising anode materials to replace graphite in conventional anodes, as it enhances safety in large scale applications. A densified binder-free LTO based anode was fabricated by the cold sintering process. The composite anode was first formed by tape casting with a binder and then was heat treated to remove the binder. The binder-free composite was humidified with water to provide a transient liquid phase and then moved onto a current collector. The wetted composite was cold sintered at 120 °C under a uniaxial pressure of 500 MPa and directly deposited on a current collector. The density of the LTO/CNF composite anode was 2.82 g/cm³ (87% relative density). The volumetric capacity densities of the cold sintered anodes were found to be ~380 mAh/cm³.