| Popis: |
In the world’s transition to a sustainable society, it is urgent to develop an electrochemical energy storage system that can simultaneously satisfy several social requirements, including high energy density, low cost, environmental friendliness, and elemental abundance. In this context, many researchers have attempted to realize an ideal battery, combined with SiOx (high-capacity and earth-abundant) anode and LiNi0.5Mn1.5O4 (high-voltage & Co-free) cathode. However, its stable operation is yet to be achieved because the reaction potentials of SiOx and LiNi0.5Mn1.5O4 are located outside the thermodynamic potential window of the traditional electrolytes. In addition, the huge volume change of SiOx easily deforms the belatedly formed passivation film. Herein, we report a long-awaited extremely stable SiOx|LiNi0.5Mn1.5O4 battery with an upper cut-off voltage of 4.9 V is successfully achieved by optimizing its overall energetic landscape. The design rationales include (i) upshifting the reaction potential of the SiOx anode closer to the reduction limit of the electrolyte, (ii) formation of a robust anion-derived passivation film on the SiOx anode surface at a higher potential prior to its huge expansion, (iii) tuning the redox potential of LiNi0.5Mn1.5O4 into the electrolyte stable window, and (iv) suppression of oxidative degradation, including Al corrosion and transition metal dissolution. |
