Improving Stability of Li-Ion Batteries by Means of Transition Metal Ions Trapping Separators. Issue 6 (1st January 2016)

• Record Type: Journal Article
• Authors: Banerjee, Anjan; Ziv, Baruch; Shilina, Yuliya; Luski, Shalom; Aurbach, Doron; Halalay, Ion C.
• Is Part Of: Journal of the Electrochemical Society. Volume 163:Issue 6(2016)
• Page Start: A1083
• Page End: A1094
• Publication Date: 2016-01-01
• Subjects: capacity fading -- Chelating agents -- Li-ion batteries -- Lithium manganese oxide -- Manganese ions dissolution -- Separators; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0081607jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Transition metal ions dissolution from positive electrodes initiates a well-known degradation mechanism in Li-ion cells, which limits their operational life. Preventing its consequences should be considered as a breakthrough in the field. We show herein that trapping Mn ions by ion-chelating polymers placed in the inter-electrode space of cells with lithium manganate spinel and Li or graphite electrodes, and greatly improves their high temperature cycling performance. Mn cations trapping separators were fabricated in-house using a commercial resin consisting of iminodiacetic acid disodium salt functional groups on a styrene divinylbenzene polymeric matrix, either by their inclusion into a separator through a phase-inversion method or by coating onto a plain commercial separator. We determined and compared the surface and cross-section morphologies, electrolyte-uptake, porosity, ionic-conductivity, and electrochemical-stability of these separators with those of a baseline separator. LMO-Li cells containing phase-inversion separators had ∼15x less Mn on the Li-electrode than cells with the baseline separator, after 100 cycles at 55°C. LMO-graphite cells with phase-inversion separators had ∼6x less Mn on the graphite-electrode, after 100 cycles at 55°C than cells with the baseline-separator. Capacity losses after cycling at 55°C were 30% and 55%, respectively, for the cells with phase-inversion and baseline separators.