1 research outputs found
Sustainable Interfaces between Si Anodes and Garnet Electrolytes for Room-Temperature Solid-State Batteries
Solid-state
batteries (SSBs) have seen a resurgence of research
interests in recent years for their potential to offer high energy
density and excellent safety far beyond current commercialized lithium-ion
batteries. The compatibility of Si anodes and Ta-doped Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub> (Li<sub>6.4</sub>La<sub>3</sub>Zr<sub>1.4</sub>Ta<sub>0.6</sub>O<sub>12</sub>, LLZTO) solid
electrolytes and the stability of the Si anode have been investigated.
It is found that Si layer anodes thinner than 180 nm can maintain
good contact with the LLZTO plate electrolytes, leading the Li/LLZTO/Si
cells to exhibit excellent cycling performance with a capacity retention
over 85% after 100 cycles. As the Si layer thickness is increased
to larger than 300 nm, the capacity retention of Li/LLZTO/Si cells
becomes 77% after 100 cycles. When the thickness is close to 900 nm,
the cells can cycle only for a limited number of times because of
the destructive volume change at the interfaces. Because of the sustainable
Si/LLZTO interfaces with the Si layer anodes with a thickness of 180
nm, full cells with the LiFePO<sub>4</sub> cathodes show discharge
capacities of 120 mA h g<sup>–1</sup> for LiFePO<sub>4</sub> and 2200 mA h g<sup>–1</sup> for the Si anodes at room temperature.
They cycle 100 times with a capacity retention of 72%. These results
indicate that the combination between the Si anodes and the garnet
electrolytes is a promising strategy for constructing high-performance
SSBs