Li distribution characterization in Li-ion batteries positive electrodes containing LixNi0.8Co0.15Al0.05O2 secondary particles (0.75⩽x⩽1.0)

Abstract

a b s t r a c tThe elemental distribution of as-received (non-charged) and charged Li-ion battery positive electrodes containing Li x Ni 0.8 Co 0.15 Al 0.05 O 2 (0.75 6 x 6 1.0) microparticles as active material is characterized by combining l-PIXE and l-PIGE techniques. PIGE measurements evidence that the Li distribution is inhomogeneous (existence of Li-rich and Li-depleted regions) in as-received electrodes corresponding with the distribution of secondary particles but it is homogeneous within the studied individual secondary micro-particles. The dependence of the Li distribution on electrode thickness and on charging conditions is characterized by measuring the Li distribution maps in specifically fabricated cross-sectional samples.These data show that decreasing the electrode thickness down to 35 lm and charging the batteries at slow rate give rise to more homogeneous Li depth profiles.

Interface Aspects in All‐Solid‐State Li‐Based Batteries Reviewed

“…IBA refers to a cluster of analytical techniques that use MeV ion beams to achieve depth‐resolved elemental profiling of solid materials up to a few micrometers beneath their surface. [ 247,248 ] Figure 18 a illustrates the working principle of several IBA techniques. During the measurement, an ion beam is directed at the sample, resulting in interactions between the incident ions and atoms in the target material.…”

Revealing Operando Transformation Dynamics in Individual Li-ion Electrode Crystallites Using X-Ray Microbeam Diffraction

“…In the first place charge transport of both electrons and Li-ions is expected to determine the active particle fraction (and hence the inhomogeneity of the reactions) in an electrode. The charge transport depends on many factors including the electrode configuration, porosity, thickness, amount and distribution of conductive additive and the current rate (Kerlau et al, 2007;Maire et al, 2008;Liu et al, 2010;Fleckenstein et al, 2011;Mima et al, 2012;Nishi et al, 2013;Katayama et al, 2014;Taminato et al, 2016). However, another interesting factor is the nature of the phase transition, either being solid solution, as occurring in NCM, or a first-order phase transition, such as occurring in LFP at low rates.…”

Irradiation Facilities of the Takasaki Advanced Radiation Research Institute

“…The distribution of Li in the positive electrode is measured using micro-PIGE analysis. It appears that micro-PIGE analysis can contribute to the optimization of the composition of the electrode material since it can measure Li distribution quantitatively with high spatial resolution [35].…”