Improvement of the Electrochemical Performance of LiNi0.8Co0.1Mn0.1O2 via Atomic Layer Deposition of Lithium-Rich Zirconium Phosphate Coatings

Sri Harsha Akella; Sarah Taragin; Yang Wang; Hagit Aviv; Alexander C Kozen; Melina Zysler; Longlong Wang; Daniel Sharon; Sang Bok Lee; Malachi Noked

doi:10.1021/acsami.1c16373

Improvement of the Electrochemical Performance of LiNi_0.8Co_0.1Mn_0.1O₂ via Atomic Layer Deposition of Lithium-Rich Zirconium Phosphate Coatings

ACS Appl Mater Interfaces. 2021 Dec 29;13(51):61733-61741. doi: 10.1021/acsami.1c16373. Epub 2021 Dec 14.

Authors

Sri Harsha Akella^{1

2}, Sarah Taragin^{1

2}, Yang Wang³, Hagit Aviv^{1

2}, Alexander C Kozen⁴, Melina Zysler^{1

2}, Longlong Wang^{1

2}, Daniel Sharon⁵, Sang Bok Lee³, Malachi Noked^{1

2}

Affiliations

¹ Department of Chemistry, Bar-Ilan University, Ramat Gan 529002, Israel.
² Bar-Ilan Institute of Nanotechnology and Advanced Materials, Ramat Gan 529002, Israel.
³ Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20740 United States.
⁴ Department of Materials Science & Engineering, University of Maryland, College Park, Maryland 20740 United States.
⁵ The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.

PMID: 34904822
DOI: 10.1021/acsami.1c16373

Abstract

Owing to its high energy density, LiNi_0.8Co_0.1Mn_0.1O₂ (NMC811) is a cathode material of prime interest for electric vehicle battery manufacturers. However, NMC811 suffers from several irreversible parasitic reactions that lead to severe capacity fading and impedance buildup during prolonged cycling. Thin surface protection films coated on the cathode material mitigate degradative chemomechanical reactions at the electrode-electrolyte interphase, which helps to increase cycling stability. However, these coatings may impede the diffusion of lithium ions, and therefore, limit the performance of the cathode material at a high C-rate. Herein, we report on the synthesis of zirconium phosphate (Zr_xPO_y) and lithium-containing zirconium phosphate (Li_xZr_yPO_z) coatings as artificial cathode-electrolyte interphases (ACEIs) on NMC811 using the atomic layer deposition technique. Upon prolonged cycling, the Zr_xPO_y- and Li_xZr_yPO_z-coated NMC811 samples show 36.4 and 49.4% enhanced capacity retention, respectively, compared with the uncoated NMC811. Moreover, the addition of Li ions to the Li_xZr_yPO_z coating enhances the rate performance and initial discharge capacity in comparison to the Zr_xPO_y-coated and uncoated samples. Using online electrochemical mass spectroscopy, we show that the coated ACEIs largely suppress the degradative parasitic side reactions observed with the uncoated NMC811 sample. Our study demonstrates that providing extra lithium to the ACEI layer improves the cycling stability of the NMC811 cathode material without sacrificing its rate capability performance.

Keywords: LiNi0.8Co0.1Mn0.1O2 (NCM811); atomic layer deposition (ALD); high rate performance; metal phosphate; suppressed parasitic reactions; surface passivation.