Comparative Analysis of Aqueous Binders for High-Energy Li-Rich NMC as a Lithium-Ion Cathode and the Impact of Adding Phosphoric Acid

Arefeh Kazzazi; Dominic Bresser; Agnese Birrozzi; Jan von Zamory; Maral Hekmatfar; Stefano Passerini

doi:10.1021/acsami.8b03657

Comparative Analysis of Aqueous Binders for High-Energy Li-Rich NMC as a Lithium-Ion Cathode and the Impact of Adding Phosphoric Acid

ACS Appl Mater Interfaces. 2018 May 23;10(20):17214-17222. doi: 10.1021/acsami.8b03657. Epub 2018 May 8.

Authors

Arefeh Kazzazi^{1

2}, Dominic Bresser^{1

2}, Agnese Birrozzi^{1

2}, Jan von Zamory^{1

2}, Maral Hekmatfar^{1

2}, Stefano Passerini^{1

2}

Affiliations

¹ Helmholtz Institute Ulm (HIU) , Helmholtzstrasse 11 , 89081 Ulm , Germany.
² Karlsruhe Institute of Technology (KIT) , P.O. Box 3640, 76021 Karlsruhe , Germany.

PMID: 29701454
DOI: 10.1021/acsami.8b03657

Abstract

Even though electrochemically inactive, the binding agent in lithium-ion electrodes substantially contributes to the performance metrics such as the achievable capacity, rate capability, and cycling stability. Herein, we present an in-depth comparative analysis of three different aqueous binding agents, allowing for the replacement of the toxic N-methyl-2-pyrrolidone as the processing solvent, for high-energy Li_1.2Ni_0.16Mn_0.56Co_0.08O₂ (Li-rich NMC or LR-NMC) as a potential next-generation cathode material. The impact of the binding agents, sodium carboxymethyl cellulose, sodium alginate, and commercial TRD202A (TRD), and the related chemical reactions occurring during the electrode coating process on the electrode morphology and cycling performance is investigated. In particular, the role of phosphoric acid in avoiding the aluminum current collector corrosion and stabilizing the LR-NMC/electrolyte interface as well as its chemical interaction with the binder is investigated, providing an explanation for the observed differences in the electrochemical performance.

Keywords: Li-rich NMC; aqueous electrode processing; battery; binder; lithium-ion cathode; phosphoric acid.