| 초록 |
Despite the unparalleled theoretical gravimetric energy, Li-O2 batteries are still under a research stage because of their insufficient cycle lives. While the reversibility in air-cathodes has been lately improved significantly by the deepened understanding on the electrode-electrolyte reaction and the integration of diverse catalysts, the stability of the Li metal interface has received relatively much less attention. The destabilization of the Li metal interface by crossover of water and O2 from the air-cathode can indeed cause as fatal degradation for the cycle life as the irreversibility of the air-cathodes. Here, it is reported that cheap poreless polyurethane (PU) separator can effectively suppress this crossover while allowing Li ions to diffuse through selectively. The PU separator also protects Li metal anodes from redox mediators. Based on the Li metal protection, a persistent capacity of 600 mAh/g is perserved for more than 200 cycles. |
