Key Applications of Lithium Hydride (LiH) in Anode Materials

The application of lithium hydride (LiH) in anode materials is mainly related to its solid electrolyte interface (SEI) formation and stability in lithium metal batteries. The following are some key points outlining the application and research progress of lithium hydride in anode materials:

1. The main component of the SEI film: Lithium hydride is the main substance of the SEI film on the surface of lithium metal, which has a significant impact on the lithium plating characteristics and cycle life of the metallic lithium anode. The structure and composition of the SEI film are critical to battery performance, in which lithium hydride plays a key role.

2. Lithium ion transport mechanism: Lithium hydride plays an important role in improving the cycle stability of lithium metal anodes. Graphene-supported lithium hydride nanoparticles are prepared by performing mixed rolling and heating reaction treatments on lithium metal and magnesium hydride (MgH2), which helps achieve rapid lithium ion transport.

3. Safety of lithium metal batteries: The accumulation of lithium hydride is considered to be one of the key factors in the failure of lithium anode powder. Suppressing the formation of lithium hydride and hydrogen gas is crucial for lithium anode protection, which may be achieved by constructing an artificial SEI film composed of materials with a higher H2 adsorption capacity than Li.

4. Prelithiation technology: The prelithiation strategy compensates for the loss of active lithium in the anode material during the first charging process by introducing additional active lithium ions, and lithium hydride can serve as an effective lithium source. Through prelithiation technology, a roll-to-roll device is used to continuously electrodeposit a lithium metal layer as a prelithiation lithium source, and the continuous and low-cost preparation of prelithiation negative electrodes has been successfully achieved.

5. New mechanism of lithium metal battery interface: There are two kinds of dendrites in the lithium metal negative electrode, one of which contains lithium hydride, which may be an important reason for the reduction of battery capacity.

6. Modification of anode materials: The low electronegativity of lithium hydride may help achieve rapid, uniform and stable lithium deposition, which is of great significance for improving the performance of anode materials and the cycle stability of batteries.

In summary, the application of lithium hydride in anode materials mainly focuses on improving the stability of the SEI film, increasing the transmission efficiency of lithium ions, and serving as a lithium source in pre-lithiation technology. It provides an important theoretical and experimental basis for improving the performance and safety of lithium metal batteries.