Chromatographic Techniques in the Research Area of Lithium Ion Batteries: Current State-of-the-Art

Abstract

Lithium ion batteries (LIBs) are widely used in numerous application areas, including portable consumer electronics, medicine, grid storage, electric vehicles and hybrid electric vehicles. One major challenge during operation and storage is the degradation of the cell constituents, which is called aging. This phenomenon drastically reduces both storage lifetime and cycle lifetime. Due to numerous aging effects, originating from both the individual LIB cell constituents as well as their interactions, a wide variety of instruments and methods are necessary for aging investigations. In particular, chromatographic methods are frequently applied for the analysis of the typically used liquid non-aqueous battery electrolytes based on organic solvents or ionic liquids. Moreover, chromatographic methods have also been recently used to investigate the composition of electrode materials. In this review, we will give an overview of the current state of chromatographic methods in the context of LIB cell research.

Clarification of Decomposition Pathways in a State‐of‐the‐Art Lithium Ion Battery Electrolyte through 13C‐Labeling of Electrolyte Components

“…Besides electrochemical decomposition, thermal stress at elevated temperatures (60–80 °C) is another reason for a ring opening polymerization of ethylene carbonate (EC) and a comparable variety of species . Overall, the identified soluble compound classes in electrolytes covered (i) oligo carbonates, (ii) carbonate ether co‐oligomers, (iii) glycols, (iv) O(F)Ps, (v) phosphate‐carbonate‐intermixtures and (vi) oligo phosphates, resulting in various different species …”

Clarification of Decomposition Pathways in a State‐of‐the‐Art Lithium Ion Battery Electrolyte through 13C‐Labeling of Electrolyte Components

“…[28,29] Besides electrochemical decomposition, thermal stress at elevated temperatures (60-80 8 8C) is another reason for aring opening polymerization of ethylene carbonate (EC) and acomparable variety of species. [25,[30][31][32][33] Overall, the identified soluble compound classes in electrolytes covered (i)o ligo carbonates,(ii)carbonate ether co-oligomers,(iii)glycols,(iv) O(F)Ps,(v) phosphate-carbonate-intermixtures and (vi)oligo phosphates,r esulting in various different species. [25,28,29,34,35] Particularly,the decomposition route to oligo phosphates via "intermediary A" was difficult to define.Recently,W ang, Xu, Eichhorn and co-workers corrected the previous assumption of lithium ethyl di-carbonate (LEDC) as am ain SEI component to the analogous monocarbonate species.…”

Optimisation of Formation and Conditioning Protocols for Lithium‐Ion Electric Vehicle Batteries

“…There are many research papers on SEI formation, and several excellent reviews. [1,[10][11][12][13] Generally, the emphasis is on SEI layer composition and morphology, typically as a function of electrolyte type and electrode surface structure. There has been previous work that correlates the SEI formation conditions to the subsequent cell performance.…”

“…The SEI layer is extremely complicated, and various spectroscopic studies have identified many components. [12][13][14] The SEI is usually considered to be a heterogeneous mosaic of different organic, organo-metallic and inorganic phases. Different products are formed as the anode voltage decreases.…”