Meso-scale characterization of lithium distribution in lithium-ion batteries using ion beam analysis techniques

Abstract

h i g h l i g h t sElemental characterization of LiNi 0.8 Co 0.15 Al 0.05 O 2 and LiFePO 4 electrodes. Li distribution characterization in the mesoscopic scale by IBA techniques. IBA techniques allow estimating active particle density contributing to Li intercalation. We relate the Li distribution inhomogeneity and battery performance. We show advantages of ion beam analysis techniques for electrode characterization. a b s t r a c tThe performance of a Li-ion battery (LIB) is mainly governed by the diffusion capabilities of lithium in the electrodes. Thus, for LIB improvement it is essential to characterize the lithium distribution. Most of the traditionally used techniques for lithium characterization give information about the local scale or in the macroscopic scale. However, the lithium behavior at the local scale is not mirrored at the macroscopic scale. Therefore, the lithium characterization in the mesoscopic scale would be of help to understand and to connect the mechanisms taking place in the two spatial scales. In this paper, we show a general description of the capabilities and limitations of ion beam analysis techniques to study the distributions of lithium and other elements present in the electrodes in the mesoscopic scale. The potential of the 7 Li(p,a 0 ) 4 He nuclear reaction to non-invasively examine the lithium distribution as a function of depth is illustrated. The lithium spatial distribution is characterized using particle induced g-ray (m-PIGE) spectroscopy. This technique allows estimating the density of the active particles in the electrode effectively contributing to the Li intercalation and/or de-intercalation. The advantages of the use of ion beam analysis techniques in comparison to more traditional techniques for electrode characterization are discussed.

Complementary Ion Beam Analysis and Raman Studies for Investigation of the Carbon Coating Impact on Li Insertion/Deinsertion Process at LiFePO4/C Electrodes

“…22,23 The probing depth for carbon with this technique is approximately 30 nm. 24 Fig. 4 displays the Raman spectra of both C-LiFePO 4 powders in the range 800-2000 cm −1 .…”

“…Nuclear microprobe has been depicted in previous works as a powerful tool capable of simultaneously and directly tracking all the elements composing a C-LiFePO 4 based electrodes as a function of its state of charge (SOC). 17,18 It especially allows visualizing the whole amount of Li contained in the electrode as well as localizing these atoms in the electrode film Consequently, a direct observation of Li-based products forming the SEI is possible. In order to link the observed products with structural properties, thickness and porosity of the different carbon coatings, these latter were investigated by Raman spectroscopy and High-Resolution Transmission Electron Microscopy (HRTEM).…”

A two layer electrode structure for improved Li Ion diffusion and volumetric capacity in Li Ion batteries

“…However, LIBs suffer from a relatively low power density of 0.2-3 kW kg −1 compared with 2-10 kW kg −1 for supercapacitors [4], which restricts LIB penetration into EVs and large-scale stationary power storage [5]. One of the LIB power constraints is due to restricted Li ion diffusion through the electrodes so that Li ion concentrations tend to be highest close to the separator immersed in a liquid electrolyte, and lowest further from the separator and adjacent to the current collector, especially under high charge/discharge rates [6], as recently shown by nuclear reaction ion beam analysis [7]. The depletion of Li ions towards the current collector leads to an inhibited contribution to energy capacity from the active material in this region, and reduced power performance [8].…”

Operando analysis of lithium profiles in Li-ion batteries using nuclear microanalysis

“…[10,11] Recently, Gonzalez-Arrabal et al showed that the lithium distribution in lithium-ion battery is dependent of electrode thickness. [12,13]…”