Pre-Lithiating SiO Anodes for Lithium-Ion Batteries by a Simple, Effective, and Controllable Strategy Using Stabilized Lithium Metal Powder

Silicon monoxide (SiO) materials have received focus as lithium-ion battery anode materials. SiO undergoes smaller volume changes during the charge (delithiation) and discharge (lithiation) processes compared with pure silicon. However, its low initial Coulombic efficiency (ICE) restricts its practical application, resulting from the formation of solid–electrolyte interphase (SEI) layer by irreversible reactions between the active materials, lithium ions, and fluoride in the electrolyte during the first discharge (lithiation) process. Pre-lithiation is recognized to be the most immediate and effective way to increase the ICE and reduce the loss of lithium. Researchers are currently trying to find simple methods to control the degree of pre-lithiation. Here, a simple and effective pre-lithiation strategy to improve the SiO anodes is presented using stabilized lithium metal powder (SLMP), styrene butadiene rubber (SBR), and toluene, which can be abbreviated as SST, as a relatively stable pre-lithiation reagent. The degree of pre-lithiation was used to adjust the ICE to 60–120%, because the ICE had a nearly linear relationship with the amount of SST. Meanwhile, the efficiency of SLMP utilization was also calculated.