Title: Optimization of nonatitanate electrodes for sodium-ion batteries

Abstract

NaTi₃O₆(OH)·2H₂O, also known as “sodium nonatitanate” (NNT) can undergo reversible sodium (de)insertion at low potentials centered around 0.3 V. The low average insertion potential and high theoretical capacity (~200 mA h g^-1 based on site considerations) suggest that it can be a promising high energy density anode material for sodium-ion batteries. However, its low practical capacity, poor capacity retention, and low initial coulombic efficiency require further material and electrode optimization. Herein, the optimization of the material properties of NNT as well as electrode engineering were used to improve these aspects of the electrochemical performance. Characterization tools including pair distribution function analysis, synchrotron X-ray diffraction, and soft and hard X-ray absorption spectroscopy were utilized to probe details of the crystal and electronic structure. Upon drying, rearrangement of the sodium ions in the interlayer space and formation of O–Na–O bridges occur. Hard and soft X-ray absorption spectroscopy show that charge transfer occurs upon discharge of the material in sodium half-cells, consistent with a reversible reductive intercalation mechanism. Furthermore, the best-performing electrodes were dehydrated at 500 °C, and the highest initial capacities of about 200 mA h g^-1 were obtained when a CMC binder was used and NNT was carbon-coated. Wrapping NNT withmore » only 1 wt% graphene also resulted in improved performance.« less

Authors:

Alvarado, Judith ^[1]; Barim, Gözde  ^[1];

• Search DOE PAGES for author "Barim, Gözde"
• Search DOE PAGES for ORCID "0000-0001-8139-925X"

Quilty, Calvin D. ^[2]; Yi, Eongyu ^[1]; Takeuchi, Kenneth J.  ^[2];

• Search DOE PAGES for author "Takeuchi, Kenneth J."
• Search DOE PAGES for ORCID "0000-0001-8129-444X"

Takeuchi, Esther S.  ^[3];

• Search DOE PAGES for author "Takeuchi, Esther S."
• Search DOE PAGES for ORCID "0000-0001-8518-1047"

Marschilok, Amy C.  ^[3];

• Search DOE PAGES for author "Marschilok, Amy C."
• Search DOE PAGES for ORCID "0000-0001-9174-0474"

Doeff, Marca M.  ^[1]

• Search DOE PAGES for author "Doeff, Marca M."
• Search DOE PAGES for ORCID "0000-0002-2148-8047"

---

+ Show Author Affiliations

1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2. Stony Brook Univ., NY (United States)
3. Stony Brook Univ., NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)

Publication Date:

Fri Sep 18 00:00:00 EDT 2020

Research Org.:

Brookhaven National Laboratory (BNL), Upton, NY (United States)

Sponsoring Org.:

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

OSTI Identifier:

1797360

Alternate Identifier(s):

OSTI ID: 1664505

Report Number(s):

BNL-221663-2021-JAAM
Journal ID: ISSN 2050-7488

Grant/Contract Number:  

SC0012704; AC02-05CH11231; SC0012673

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Materials Chemistry. A

Additional Journal Information:

Journal Volume: 8; Journal Issue: 38; Journal ID: ISSN 2050-7488

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE