Preliminary assessment of glass preparation by melting cathode-active material NCM622 with boric acid

This work investigated for the first time the making of glasses with cathode-active material Li(Ni_0.6Co_0.2Mn_0.2)O₂ (NCM622) and boric acid as strategy to manage the Li-ion battery material. The raw materials were mixed in various proportions guided by xNCM622-(100 – x)B₂O₃ with x = 15, 20, 25 and 30 mol% nominal compositions and melted in ambient atmosphere at 1150 °C. The prepared materials were subsequently studied by density, optical transmission, X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, and differential scanning calorimetry (DSC) measurements. The densities increased progressively within 2.3054–2.6486 g/cm³. The transmission spectra showed increasingly the presence of the transition metals most notably Ni²⁺ and Co²⁺, indicating their reduction took place during melting. XRD supported glass formation up to 25 mol% NCM622 with some crystallization induced at 30 mol% NCM622. The FT-IR data was consistent with the occurrence of trigonal BO₃ and tetrahedral BO₄ units, wherein a decline in BO₄ units was indicated with increasing NCM622 content. The thermal characterization by DSC then showed glass stability decreased with NCM622 concentration. However, the glass transition temperatures increased only up to 25 mol% NCM622, indicating deviation thereafter for the glass-ceramic obtained with 30 mol% NCM622. The preliminary assessment carried out stimulates additional research pertaining to vitrification as an approach for the management or upcycling of lithium battery components.