Comprehensive Characterization of Shredded Lithium-Ion Battery Recycling Material.

Herein we report on an analytical study of dry-shredded lithium-ion battery (LIB) materials with unknown composition. Samples from an industrial recycling process were analyzed concerning the elemental composition and (organic) compound speciation. Deep understanding of the base material for LIB recycling was obtained by identification and analysis of transition metal stoichiometry, current collector metals, base electrolyte and electrolyte additive residues, aging marker molecules and polymer binder fingerprints. For reversed engineering purposes, the main electrode and electrolyte chemistries were traced back to pristine materials. Furthermore, possible lifetime application and accompanied aging was evaluated based on target analysis on characteristic molecules described in literature. With this, the reported analytics provided precious information for value estimation of the undefined spent batteries and enabled tailored recycling process deliberations. The comprehensive feedstock characterization shown in this work paves the way for targeted process control in LIB recycling processes.

Implementation of orbitrap mass spectrometry for improved GC-MS target analysis in lithium ion battery electrolytes.

The implementation of orbitrap mass spectrometry for target analysis of volatile species in aged lithium-ion batteries was performed in a case study on butyl carbonates. In comparison to previously applied single quadrupole-based methods, major improvements were obtained.•Sensitivity was improved by effectively background free extracted ion chromatograms of identified marker fragment ions.•Typical isobaric interferences of typical carbonate fragment ions e.g. caused by column bleeding were identified and false positive identification avoided.•Analysis of isotope labeled electrolytes was optimized regarding mass spectrometric data reliability with mass accuracies <0.5 ppm and mass resolutions >100,000.

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

The decomposition of state-of-the-art lithium ion battery (LIB) electrolytes leads to a highly complex mixture during battery cell operation. Furthermore, thermal strain by e.g., fast charging can initiate the degradation and generate various compounds. The correlation of electrolyte decomposition products and LIB performance fading over life-time is mainly unknown. The thermal and electrochemical degradation in electrolytes comprising 1 m LiPF6 dissolved in 13 C3 -labeled ethylene carbonate (EC) and unlabeled diethyl carbonate is investigated and the corresponding reaction pathways are postulated. Furthermore, a fragmentation mechanism assumption for oligomeric compounds is depicted. Soluble decomposition products classes are examined and evaluated with liquid chromatography-high resolution mass spectrometry. This study proposes a formation scheme for oligo phosphates as well as contradictory findings regarding phosphate-carbonates, disproving monoglycolate methyl/ethyl carbonate as the central reactive species.