Facile synthesis of anhydrous Li 2 B 12 H 12 with high purity by solvent-free method

Closo-Borate Gel Polymer Electrolyte with Remarkable Electrochemical Stability and a Wide Operating Temperature Window

A major challenge in the pursuit of higher-energy-density lithium batteries for carbon-neutral-mobility is electrolyte compatibility with a lithium metal electrode. This study demonstrates the robust and stable nature of a closo-borate based gel polymer electrolyte (GPE), which enables outstanding electrochemical stability and capacity retention upon extensive cycling. The GPE developed herein has an ionic conductivity of 7.3 × 10^-4  S cm^-2 at room temperature and stability over a wide temperature range from -35 to 80 °C with a high lithium transference number ( tLi+$t_{{\rm{Li}}}^ + $ = 0.51). Multinuclear nuclear magnetic resonance and Fourier transform infrared are used to understand the solvation environment and interaction between the GPE components. Density functional theory calculations are leveraged to gain additional insight into the coordination environment and support spectroscopic interpretations. The GPE is also established to be a suitable electrolyte for extended cycling with four different active electrode materials when paired with a lithium metal electrode. The GPE can also be incorporated into a flexible battery that is capable of being cut and still functional. The incorporation of a closo-borate into a gel polymer matrix represents a new direction for enhancing the electrochemical and physical properties of this class of materials.

In Situ Formed Li-B-H Complex with High Li-Ion Conductivity as a Potential Solid Electrolyte for Li Batteries

Li-B-H complexes facilely prepared via partial dehydrogenation of LiBH₄ are presented in this study as solid electrolytes for Li batteries. An exceptionally high Li-ion conductivity is found for the Li-B-H complex with 7.5 wt % H₂ desorption under 3 bar H₂ pressure, which reaches 2.7 × 10^-4 S cm^-1 at 35 °C, more than 4 orders higher than that of LiBH₄. In-depth characterizations show that LiH and [Li₂B₁₂H_{11+1/ n}] _n are in situ formed in the LiBH₄ matrix and the interface layer between [Li₂B₁₂H_{11+1/ n}] _n and LiBH₄ is believed to be responsible for the high Li-ion conductivity. Moreover, this Li-B-H complex also exhibits excellent electrochemical stability, which enables the stable cycling of all-solid-state batteries at room temperature.

Facile preparation and dehydrogenation of unsolvated KB3H8

A convenient route was developed to produce unsolvated KB₃H₈. This compound can release hydrogen and minor boranes by subsequent cleavage of its B–H and B–H–B bonds in the 150–250 °C temperature range. And pure K₂B₁₂H₁₂ can be prepared through KB₃H₈ pyrolysis, which is an optional approach to produce dodecaborate compounds.