A Comprehensive Understanding on How Ultrathin Coating Layers on Active Particles Enhance Battery Performance Significantly

Thursday, 1 June 2017: 10:40
Grand Salon D - Section 21 (Hilton New Orleans Riverside)
S. Sarkar, R. L. Patel (Missouri University of Science and Technology, Rolla), X. Liang, and J. Park (Missouri University of Science and Technology)
The Atomic Layer Deposition (ALD) coating strategy on active materials of Li-ion battery is known as an effective way than other coating techniques to enhance battery performance, but there is still substantial uncertainty about how these coating layers are the origin of the enhanced performance. A comprehensive model is developed based on experimental measurements and theoretical analysis to study how different coating strategies affect the mechanical and electrochemical responses of a battery system. Although it appears that a thicker coating helps to provide higher capacity and cycle life improvement, but a too-thick layer may act as a migration barriers and facilitate much slower lithium transport, resulting in capacity decrease. Further, the developed model quantitatively predicts the capacity retention of coated particles by mitigating the transition metal ion dissolution, which is one critical capacity fade mechanism of the metal oxide cathode materials. This quantitative study reveals the trade-off mechanism of ALD coating between the species transport (capacity) and protection (lifetime), which could be an important guidance for thin-coating based strategies for battery performance enhancement.