Tuning B₄C crystal growth with polyol-modified gel precursors and assessing needle-like B₄C for energy storage

This article introduces an innovative approach to tailor the morphology of boron carbide (B₄C) particles by adjusting the polyols in polymeric precursors. This modification enables the control of the C/B₂O₃ ratio of the precursor and the formation of H₃BO₃ crystals on its surface. These H₃BO₃ crystals play a crucial role in inducing the growth of nano boron carbide particles with a high aspect ratio. Scanning electron microscopy (SEM) images depict that precursors lacking the ethylene glycol component yield polyhedral-equiaxed B₄C particles. Conversely, the use of precursors containing 50 mol% ethylene glycol and the lowest C/B₂O₃ ratio leads to the formation of B₄C particles with a needle-like morphology. Moreover, the influence of particle morphology on the electrochemical properties of boron carbide was investigated, and the potential of boron carbide in energy storage devices was delved into, with the needle-like boron carbide particles showed superior performance a specific capacitance of 139.7 F/g at 1 A/g and also showcased a long-term stability of 66 % after 5000 cycles.