NANOTEK INSTRUMENTS INC — Department of Defense SBIR Phase I: AF192-038

Description

This proposal seeks to develop a high-efficiency and long-cycle-life graphene-silicon anode by an innovative pre-lithiation strategy. Graphene possesses ultra-high mechanical strength and high electrical conductivity, thereby limiting the anode expansion during charging and also improving the utilization of the semi-conductive silicon material. To address the key issue inhibiting widespread applications, the efficiency and cycle life of Si/SiO anode with higher capacity (> 600 mAh/g) is still unsatisfactory. Here, we introduce an effective way to further pre-lithiated graphene-silicon anode by investigating various methods (chemical/electrochemical/vapor deposition pre-lithiation on electrodes or active material powder). Therefore, additional lithium not only compensates first cycle capacity loss due to SEI (solid-electrolyte-interface) formation at the anode but also stabilizes cycling capacity degradation loss due to repeated SEI growth. Several goals are expected by the completion of Phase I: (a) manufacturing pre-lithiated graphene-silicon anodes that can deliver > 1,200 mAh/g (SiOx based) with FCE over 80% and/or > 2,000 mAh/g (nano-Si based) with FCE over 92%, (b) demonstrating a long-cycle-life graphene-silicon composite anode with a cycle life of > 300 cycles. This project will be a pioneer work leading to the wide commercial use of high-energy-density lithium-ion batteries (> 300-400 Wh/kg) enabled by the pre-lithiated graphene-silicon anode.