Rechargeable silicon battery for storing renewable energy
silicon battery, photovoltaics, energy, technology, 2022
Researchers from the Technion Institute of Technology – Israel have designed a rechargeable silicon (Si) battery for constant storage applications which can be reversibly discharged to 1,1 V and charged to 1,5 V.
The philosophy of the silicon battery
The device combines a reversible Si anode with halide cathodes and uses hybrid electrolytes to allow the cells to be recharged. In the proposed system configuration, the silicon dissolves during the battery discharge process and during charging, elemental Si is deposited. Hybrid electrolytes, which were adapted with halides such as bromine and iodine, reversibly support Si electrolysis and electrodeposition processes in the same cell formation.
"During the discharge process, the electrolysis of Si occurs at the anode and the dissolved halides are reduced at the cathode," the scientists said. "The charging process involves electrodeposition of Si and oxidation of halides."
They assembled all the cell components in an Ar-filled glovebox and prepared the silicon electrodes from 4′′ n-type silicon wafers. They also let the cells rest for three hours to detect possible leakage and used platinum foil as counter electrodes.
After several cycles, the silicon battery achieved a coulombic efficiency of about 80%. While it showed gradual cell degradation. The cell showed limited power capabilities of 0,1 mA cm –2,” the scientists said. “The presence of appreciable fluorine species is crucial for both surface activation and battery operation. And their depletion is directly linked to the degradation of cell performance."
The academics presented the new silicon battery concept in the study "Rechargeable Silicon Redox Batteries". Which was recently published in Advanced Energy Materials.
“The feasibility of the new silicon battery design paves the way for Appliances higher specific energy targeting the low power application segments. These findings undoubtedly warrant further research and optimization of electrolytes,” they said.
