Comparison of xenon and gallium sources on the detection and mapping of lithium in Li‐containing materials by using ToF‐SIMS combined FIB‐SEM

Abstract

Li can find itself a wide range of applications since it is the lightest metal. However, Li detection by microscopy-based techniques is problematic because of the highly susceptible nature during electron beam irradiation. ToF-SIMS is a versatile technique to detect Li but the detection of light materials is also problematic due to the large ion contaminated zone and low sputtering yield. By combining ToF-SIMS with a recently launched Xe ion source FIB-SEM, which has small ion contamination and high sputtering yield features, can produce more realistic data at near surface and below the surface region especially for the detection of lightweight materials such as Li. In this study, Li detection and mapping capabilities of ToF-SIMS attached to the FIB-SEM with Ga and Xe ion sources were discussed for Al incorporated Li 7 La 3 Zr 2 O 12 solid electrolyte sample that contains Li and Al rich regions at triple junctions. In spite of smoother milling from Ga source, Xe performs more precisely in Li mapping. Low ion contaminated zone, high sputtering yield and low straggling obtained from Monte Carlo simulations are the main advantages of Xe ion sources. The Li detection efficiency for Xe is higher than Ga source discriminating the LiAlO 2 phase placed at the triple junctions of grains and La 2 Zr 2 O 7 regions placed at the outer side of LLZO neighbouring the LiAlO 2 phase.

Recent advances in in situ and operando characterization techniques for Li7La3Zr2O12-based solid-state lithium batteries

“…28 When combined with FIB technique to investigate interior compositions, a xenon ion source should be used as it provides low ionic contamination, high sputtering yield, low scattering and greater precision for Li mapping compared to a Ga ion source. 232 However, milling of the surface obtained using a xenon ion source is not as smooth as seen when using a Ga ion source. Moreover, in situ ToF-SIMS technique that can measure under an electrochemical response is not yet available.…”

Degradation Diagnostics from the Subsurface of Lithium‐Ion Battery Electrodes

“…[20][21][22] In order to achieve the chemical survey, mass spectrometry technologies have stepped into the spotlight. [16,[23][24][25][26][27][28][29][30] Mass spectrometry is one of the widely accepted techniques to detect light elements including lithium. Among the commonly used mass spectrometry techniques, the secondary-ion mass spectrometry (SIMS) technique can preserve the spatial information of samples due to the direct ionization processes to generate analyte ions, while other techniques need two steps in time or space to evaporate (atomize) and ionize separately.…”

“…This has been proved by both experimental observations (Figure S1b) and theoretical simulations (Figure S1c) from our recently published paper. [44] In this study, commercial lithium nickel manganese cobalt oxide (NMC532, LiNi 0.5 Mn 0.3 Co 0.2 O 2 )/graphite, conductive carbon black, and polyvinylidene fluoride (PVDF) with a mass ratio of 90:5:5 were adopted for the cathode/anode electrodes preparation (See details of battery assembly and cycling performance in the Experimental Section and Figure S2). Electrode materials with a depth of more than 50 lm were sputtered away from the top by a Xe + plasma FIB (PFIB) milling technique (Figure 1a).…”

“…This has been proved by both experimental observations (Figure ) and theoretical simulations (Figure c) from our recently published paper. [ 44 ]…”