Scalable Preparation of Freestanding Flexible Si Nanoparticles-Carbon Nanotubes Composite Paper Anodes for Lithium Ion Batteries and Their Prelithiation by Stabilized Lithium Metal Powder

Freestanding flexible light-weight silicon nanoparticles-carbon nanotubes (SiNPs-CNTs) composite paper anodes for lithium ion batteries (LIBs) have been prepared by ultrasonication and pressure filtration without adoption of conductive additive, binder or current collector. Electrochemical testing has shown that the SiNPs-CNTs composite electrode material achieves first cycle specific discharge and charge capacities of 2298 and 1492 mAh/g, respectively. To address the first cycle irreversibility, stabilized lithium metal powder (SLMP) has been utilized to prelithiate our composite anodes. Compared to cell without SLMP, the cell with an SLMP loading of SLMP/anode mass ratio of 0.26 has the first cycle irreversible capacity loss reduced from 806 to 28 mAh/g and the first cycle coulombic efficiency increased from 65 to 98%. The relationship between different SLMP loading and the cell performance has been established to optimize the construction of Si-based cells. Use of the SiNPs-CNTs anodes incorporating SLMP as the source of lithium opens the door to a broad range of non-lithium-providing cathode materials and enables the creation of future high capacity and high energy LIBs.