Synthesis and Characterization of CuFe₂O₄ Nano/Submicron Wire–Carbon Nanotube Composites as Binder-free Anodes for Li-Ion Batteries

Journal Article · Tue Feb 20 00:00:00 EST 2018 · ACS Applied Materials and Interfaces

DOI:https://doi.org/10.1021/acsami.8b00244· OSTI ID:1438327

Wang, Lei ^[1]; Bock, David C. ^[2]; Li, Jing ^[1]; Stach, Eric A. ^[3]; Marschilok, Amy C. ^[4]; Takeuchi, Kenneth J. ^[1]; Takeuchi, Esther S. ^[4]

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1. State Univ. of New York at Stony Brook, Stony Brook, NY (United States)
2. Brookhaven National Lab. (BNL), Upton, NY (United States)
3. Brookhaven National Lab. (BNL), Upton, NY (United States); Univ. of Pennsylvania, Philadelphia, PA (United States)
4. State Univ. of New York at Stony Brook, Stony Brook, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)

Here, a series of one-dimensional CuFe₂O₄ nano/sub-micron wires possessing different diameters, crystal phases, and crystal sizes have been successfully generated using a facile template-assisted co precipitation reaction at room temperature, followed by a short post-annealing process. The diameter and the crystal structure of the resulting CuFe₂O4 (CFO) wires were judiciously tuned by varying the pore size of the template and the post-annealing temperature, respectively. Carbon nanotubes (CNTs) were incorporated to generate CFO-CNT binder-free anodes, and multiple characterization techniques were employed with the goal of delineating the relationships between electrochemical behavior and the properties of both the CFO wires (crystal phase, wire diameter, crystal size) and the electrode architecture (binder-free vs. conventionally prepared approaches). The study reveals several notable findings. First, the crystal phase (cubic or tetragonal) did not influence the electrochemical behavior in this CFO system. Second, regarding crystallite size and wire diameter, CFO wires with larger crystallite sizes exhibit improved cycling stability, while wires possessing smaller diameters exhibiting higher capacities. Finally, the electrochemical behavior is strongly influenced by the electrode architecture, with CFO-CNT binder-free electrodes demonstrating significantly higher capacities and cycling stability compared to conventionally prepared coatings. The mechanism(s) associated with the high capacities under low current density but limited electrochemical reversibility of CFO electrodes under high current density were probed via x-ray absorption spectroscopy (XAS) mapping with sub-micron spatial resolution for the first time. Results suggest that the capacity of the binder-free electrodes under high rate is limited by the irreversible formation of Cu⁰, as well as limited reduction of Fe³⁺, to Fe²⁺ not Fe⁰. The results (1) shed fundamental insight into the reversibility of CuFe₂O₄ materials cycled at high current density and (2) demonstrate that a synergistic effort to control both active material morphology and electrode architecture is an effective strategy for optimizing electrochemical behavior.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States); Energy Frontier Research Centers (EFRC) (United States). Center for Mesoscale Transport Properties (m2M)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: SC0012704
• OSTI ID: 1438327
• Report Number(s): BNL--205692-2018-JAAM
• Journal Information: ACS Applied Materials and Interfaces, Journal Name: ACS Applied Materials and Interfaces Journal Issue: 10 Vol. 10; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
Li-ion batteries
X-ray absorption spectroscopy
X-ray microfluorescence mapping
binder-free electrode
copper ferrite
nano/submicron wires