Doubling Reversible Capacities in Epitaxial Li 4 Ti 5

Title

Doubling Reversible Capacities in Epitaxial Li 4 Ti 5 O 12 Thin Film Anodes for Microbatteries

 Author

Cunha, Daniel M. (University of Twente)
Hendriks, Theodoor A. (University of Twente)
Vasileiadis, A. (TU Delft RST/Storage of Electrochemical Energy) ORCID 0000-0001-9761-7936
Vos, Chris M. (University of Twente)
Verhallen, T.W. (TU Delft RST/Storage of Electrochemical Energy) ORCID 0000-0002-8473-4321
Singh, Deepak P. (University of Twente)
Wagemaker, M. (TU Delft RST/Storage of Electrochemical Energy) ORCID 0000-0003-3851-1044
Huijben, Mark (University of Twente)

Date

2019

 Abstract

Despite the lower gravimetric capacity, Li 4 Ti 5 O 12 is an important alternative to graphite anodes, owing to its excellent high temperature stability, high rate capability, and negligible volume change. Although surfaces with lithium compositions exceeding Li 7 Ti 5 O 12 were observed previously during the first charge-discharge cycles, no stable reversible capacities were achieved during prolonged cycling. Here, structural engineering has been applied to enhance the electrochemical performance of epitaxial Li 4 Ti 5 O 12 thin films as compared to polycrystalline samples. Variation in the crystal orientation of the Li 4 Ti 5 O 12 thin films led to distinct differences in surface morphology with pyramidal, rooftop, or flat nanostructures for respectively (100), (110), and (111) orientations. High discharge capacities of 280-310 mAh·g -1 were achieved due to significant surface contributions in lithium storage. The lithiation mechanism of bulk Li 4 Ti 5 O 12 thin films was analyzed by a phase-field model, which indicated the lithiation wave to be moving faster along the grain boundaries before moving inward to the bulk of the grains. The (100)-oriented Li 4 Ti 5 O 12 films exhibited the highest capacities, the best rate performance up to 30C, and good cyclability, demonstrating enhanced cycle life and doubling of reversible capacities in contrast to previous polycrystalline studies.


Subject

battery anode
crystal orientation
epitaxial thin film
Li Ti O
surface capacity

 To reference this document use:

http://resolver.tudelft.nl/uuid:2f47dc48-41df-4edc-b152-ea7904fdf111

 DOI

https://doi.org/10.1021/acsaem.9b00217

 ISSN

2574-0962

 Source

ACS Applied Energy Materials, 2 (5), 3410-3418

 Part of collection

Institutional Repository

 Document type

journal article

 Rights

© 2019 Daniel M. Cunha, Theodoor A. Hendriks, A. Vasileiadis, Chris M. Vos, T.W. Verhallen, Deepak P. Singh, M. Wagemaker, Mark Huijben
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