Title: Improved electrochemical cycling stability of intercalation battery electrodes via control of material morphology

Abstract

Using a model tunnel manganese oxide with the todorokite crystal structure (T-MnO₂), we reveal that controlling the morphology of the active material can improve the cycling stability of intercalation battery electrodes. The T-MnO₂ structure is built from tunnels that provide spacious 1D diffusion channels for charge-carrying ions. Taking advantage of the unique ability to synthesize T-MnO₂ in the form of both highly crystalline two-dimensional (2D) nanoplatelets and one-dimensional (1D) nanowires through a facile hydrothermal growth method, we investigated the effect of nanoscale particle dimensions on reversible battery cycling. Insertion of ions into the tunnels results in anisotropic expansion of the structure, making T-MnO₂ with different morphologies an excellent model platform to understand how intercalation-induced volume change, typically leading to the deterioration of the electrode performance over extended cycling, can be controlled through synthesis of targeted morphologies. T-MnO₂ nanowires showed not only significantly improved capacity retention but also substantially higher specific capacity than the T-MnO₂ nanoplatelets. The enhanced electrochemical properties of the nanowire electrodes could be attributed to the larger surface-to-volume ratio than that of nanoplatelets, resulting in higher contact area with electrolyte for the nanowires. Moreover, due to the smaller cross-sectional area of the nanowires, volume expansion and contraction perpendicularmore » to the structural tunnels induced by reversible ion intercalation occurs in a more facile fashion. In this research we demonstrate that chemically controlling morphology and producing particles with nanostructure dimensionality replicating that of atomic structure (i.e., 1D morphology and 1D structure) makes it possible to enhance material performance.« less

Authors:

Bylesa, Bryan ^[1]; Clites, Mallory ^[1]; Cullen, David A.  ^[2];

• Search DOE PAGES for author "Cullen, David A."
• Search DOE PAGES for ORCID "0000-0002-2593-7866"

More, Karren  ^[2];

• Search DOE PAGES for author "More, Karren"
• Search DOE PAGES for ORCID "0000-0001-5223-9097"

Pomerantseva, Ekaterina ^[1]

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+ Show Author Affiliations

1. Drexel Univ., Philadelphia, PA (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:

Wed Sep 12 00:00:00 EDT 2018

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1531232

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Ionics

Additional Journal Information:

Journal Volume: 25; Journal Issue: 2; Journal ID: ISSN 0947-7047

Publisher:

Springer

Country of Publication:

United States

Language:

English

Subject:

77 NANOSCIENCE AND NANOTECHNOLOGY; Manganese oxide with todorokite structure; Two-dimensional nanoplatelets; One-dimensional nanowires; Intercalation compounds; Batteries