Modified electrochemical performance of high potential cathode using a sand-like carbonate electrolyte

The electrochemical performance of LiNi 0.5 Mn 1.5 O 4 is investigated in a sand-like carbonate electrolyte containing 4   wt.% lithium metasilicate (Li 2 SiO 3 ). The capacity fading rate of the LiNi 0.5 Mn 1.5 O 4 electrode working in the sand-like electrolyte (2-5   V) is reduced to 0.171 mAh g −1 per cycle, quite smaller than the value of 0.613 mAh g −1 per cycle in the electrolyte without Li 2 SiO 3 . The capacity of 159.5 mAh g −1 is delivered at 0.5   C after 118 cycles while it is only 99.4 mAh g −1 for the Li 2 SiO 3 -free counterpart. Cyclic voltammetry, scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopic measurements are conducted to explore the modification mechanism. It is found that the anodic stability of the sand-like electrolyte is improved compared to the base electrolyte. The Li 2 SiO 3 precipitates on the electrode surface make contribution to the performance enhancement of the cathode at high potential.