Enhancement of V2O5 Li-ion cathode stability by Ni/Co doped Li-borate-based glass.

In this research, we investigate the stability of a Li-ion cathode created by mixing a borate based glass which has been doped with Ni/Co and vanadium pentoxide (V2O5). V2O5 has a high specific capacity in battery systems because of its layered structure and variety of oxidation states. However, due to the flimsy structure, the capacity stability of V2O5 is fairly low. In this case, we seek to overcome the problem by mixing Ni/Co-doped borate based glass. The voltage-capacity graph demonstrates that the form of the glass mix was changed from a stairway shape to a straight line while the capacity was not much decreased. The crystallography study using X-ray diffractograms looked at whether the cycling test had changed the crystal structure of V2O5. The X-ray Absorption Near Edge Structure (XANES) results also reveal that V2O5's oxidation state changed from V5+ to V4+. The glass mix can retain more of the V5+ state, indicating that glass mixture helps to release the Li-ions trapped in the structure. The findings of this study might contribute to the rapid advancement of renewable energy and electric vehicle technology.

Enhanced Electrochemical Performance of Sugarcane Bagasse-Derived Activated Carbon via a High-Energy Ball Milling Treatment.

Activated carbon (AC) from sugarcane bagasse was prepared using dry chemical activation with KOH. It was then subjected to a high-energy ball milling (HEBM) treatment under various milling speeds (600, 1200 and 1800 rpm) to produce AC nanoparticles from micro-size particles. The AC samples after the HEBM treatment exhibited reduced particle sizes, increased mesopore volume and a rich surface oxygen content, which contribute to higher pseudocapacitance. Notably, different HEBM speeds were used to find a good electrochemical performance. As a result, the AC/BM12 material, subjected to HEBM at 1200 rpm for 30 min, exhibited the highest specific capacitance, 257 F g-1, at a current density 0.5 A g-1. This is about 2.4 times higher than that of the AC sample. Moreover, the excellence capacitance retention of this sample was 93.5% after a 3000-cycle test at a current density of 5 A g-1. Remarkably, a coin cell electrode assembly was fabricated using the AC/BM12 material in a 1 M LiPF6 electrolyte. It exhibited a specific capacitance of 110 F g-1 with a high energy density of 27.9 W h kg-1.