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Energy and Power ProductionElectrochemical Energy Storage

Conformal Surface Coatings to Enable High Volume Expansion Li-Ion Anode Materials

Authors: Leah A Riley; Andrew S Cavanagh; Steven M George; Yoon S Jung; Yanfa Yan; Se-Hee Lee; Anne C Dillon; NATIONAL RENEWABLE ENERGY LAB GOLDEN CO
Abstract:
An alumina surface coating is demonstrated to improve electrochemical performance of MoO3 nanoparticles as high capacity/ high-volume expansion anodes for Li-ion batteries. Thin, conformal surface coatings were grown using atomic layer deposition (ALD) that relies on self-limiting surface reactions. ALD coatings were tested on both individual nanoparticles and prefabricated electrodes containing conductive additive and binder. The coated and non-coated materials were characterized using transmission electron microscopy, energy-dispersive X-ray spectroscopy, electrochemical impedance spectroscopy and galvanostatic charge/discharge cycling. Importantly, increased stability and capacity retention was only observed when the fully fabricated electrode was coated. The alumina layer both improves the adhesion of the entire electrode, during volume expansion/contraction and protects the nanoparticle surfaces. Coating the entire electrode also allows for an important carbothermal reduction process that occurs during electrode pre-heat treatment. ALD is thus demonstrated as a novel and necessary method that may be employed to coat the tortuous network of a battery electrode.

Limitations: APPROVED FOR PUBLIC RELEASE
Description: Journal article
Pages: 8
Report Date: 12 Jul 2010
Contract Number: HR0011-06-1-0048
Report Number: A673355
Keywords relating to this report:
ATOMIC LAYER EPITAXY
COATINGS
ELECTRODES
KINETICS
LITHIUM BATTERIES
NANOPARTICLES
PHASE TRANSFORMATIONS
REPRINTS
SURFACE ANALYSIS
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