prelithiated

Prelithiation is a process used in lithium-ion battery manufacturing in which additional lithium is introduced to the negative electrode before full cell assembly. The aim is to compensate for lithium that is irreversibly consumed during the first charge, often in the formation of the solid electrolyte interphase and other side reactions, thereby improving the initial coulombic efficiency and the usable energy of the cell.

Methods of prelithiation vary. Chemical prelithiation uses a lithium source, such as metallic lithium or lithium-containing compounds, to transfer lithium to the anode material in a controlled manner. Electrochemical prelithiation employs a dedicated setup or a half-cell configuration to drive lithium into the electrode before completing the full cell. Mechanical prelithiation can involve physical contact or milling processes that incorporate lithium into the electrode material during processing. Each method seeks to establish a stable, preloaded lithium inventory without compromising material integrity.

Prelithiation is particularly relevant for high-capacity anodes that suffer large first-cycle losses, such as silicon-based materials, silicon alloys, and some conversion-type or alloying anodes. By providing extra lithium upfront, prelithiation can improve the practical energy density and reduce the need for excess lithium in the cathode or electrolyte.

Challenges associated with prelithiation include controlling the extent and uniformity of lithium incorporation, ensuring compatibility with subsequent electrode cyclability and electrolyte stability, and managing safety concerns associated with handling reactive lithium. Economic and manufacturing considerations, such as process complexity and scalability, also influence the adoption of prelithiation techniques in commercial cells.