Silicon Oxide (SiO) Anode Enabled by a Conductive Polymer Binder and Performance Enhancement by Stabilized Lithium Metal Power (SLMP)

Abstract

Silicon alloys have the highest specific capacity when used as anode material for lithium-ion batteries, however, the drastic volume change inherent in their use causes formidable challenges toward achieving stable cycling performance. Large quantities of binders and conductive additives are typically necessary to maintain good cell performance. In one embodiment of the invention, only 2% (by weight) functional conductive polymer binder without any conductive additives was successfully used with a micron-size silicon monoxide (SiO) anode material, demonstrating stable and high gravimetric capacity (>1000 mAh/g) for ˜500 cycles and more than 90% capacity retention. Prelithiation of this anode using stabilized lithium metal powder (SLMP®) improves the first cycle Coulombic efficiency of a SiO/NMC full cell from ˜48% to ˜90%. This combination enables good capacity retention of more than 80% after 100 cycles at C/3 in a lithium-ion full cell.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This U.S. Utility Application claims priority to U.S. Provisional Application Ser. No. 62 / 012,876 filed Jun. 16, 2014, which application is incorporated herein by reference as if fully set forth in their entirety.STATEMENT OF GOVERNMENTAL SUPPORT[0002]The invention described and claimed herein was made in part utilizing funds supplied by the U.S. Department of Energy under Contract No. DE-ACO2-05CH11231 between the U.S. Department of Energy and the Regents of the University of California for the management and operation of the Lawrence Berkeley National Laboratory. The government has certain rights in this invention.BACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]The present invention relates to the field of Lithium ion batteries.[0005]2. Related Art[0006]Rechargeable lithium-ion batteries hold great promise as energy storage devices to solve the temporal and geographical mismatch between the supply and demand of electrici...

AI Technical Summary

Problems solved by technology

However, the current electrode materials have limited specific charge storage capacity and cannot achieve the higher energy density, higher power density, and longer lifespan that all these important applications require.

However, it is challenging to overcome the issues associated with alloying and conversion reactions, which involve large structure and volume changes (400% volume expansion for Si) during Li+ ion insertion and extraction.

These issues can cause large hysteresis in the charge and discharge potentials, low power rate, and short cycle life, due to material instability, and poor electron and ion conduction.

However, low cost and fast throughput processes with great mass and morphology control are still desirable to reach the full potential for commercialization.

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