The Role of Silicate Enrichment on the Discharge Duration of Silicon-Air Batteries

Silicon-air batteries are candidates for next generation batteries from non-critical raw materials. However, current silicon-air batteries with alkaline electrolytes suffer from premature termination of the discharge process. To understand this process, we investigated the correlation of dissolved silicon in the electrolyte and the discharge duration until passivation. The air- and Si-electrode could be excluded as the source of the voltage drop, while the concentration of silicates in the electrolyte was identified as the decisive factor. A low silicate concentration in the electrolyte was found to be crucial for a sustained discharge of silicon-air batteries with alkaline electrolytes and full consumption of the silicon electrode used in these conditions was shown.