WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
CREST, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan.
Sci Rep. 2016 Sep 19;6:33466. doi: 10.1038/srep33466.
High-energy-density rechargeable Li-O2 batteries are one of few candidates that can meet the demands of electric drive vehicles and other high-energy applications because of the ultra-high theoretical specific energy. However, the practical realization of the high rechargeable capacity is usually limited by the conflicted requirements for porous cathodes in high porosity to store the solid reaction products Li2O2 and large accessible surface area for easy formation and decomposition of Li2O2. Here we designed a hierarchical and bicontinuous nanoporous structure by introducing secondary nanopores into the ligaments of coarsened nanoporous gold by two-step dealloying. The hierarchical and bicontinuous nanoporous gold cathode provides high porosity, large accessible surface area and sufficient mass transport path for high capacity and long cycling lifetime of Li-O2 batteries.
高能量密度可再充电 Li-O2 电池是少数几种能够满足电动汽车和其他高能量应用需求的候选电池之一，因为它具有超高的理论比能量。然而，高可再充电容量的实际实现通常受到多孔阴极的高孔隙率以储存固体反应产物 Li2O2 和大的可及表面积以方便 Li2O2 的形成和分解之间的矛盾要求的限制。在这里，我们通过两步脱合金将次级纳米孔引入粗化纳米多孔金的连接键中，设计了一种分级和双连续的纳米多孔结构。分级和双连续的纳米多孔金阴极提供了高孔隙率、大的可及表面积和充足的传质路径，从而实现了高容量和长循环寿命的 Li-O2 电池。
