Lithium-air batteries possess a high theoretical energy density among the current battery technologies, and are expected to become the driving power for electric vehicles. However, the practical application of lithium air batteries is handicapped by their poor cycle life, high over-charge potential and low energy efficiency. Numerous studies have performed to improve the kinetics of the electrochemical reaction. Making a good oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalyst system is under intense scrutiny. In this work, we report a rational design of air electrode, which derives from biomass and presents a three-dimensional porous carbon architecture with high specific surface and large volume expansion coefficient. Combining with a soluble catalyst, this oxygen electrode presents an ultrahigh areal specific capacity of 7.95 mAh/cm2 and a long cycling life up to 1000 cycles with suppressed polarization (about 0.46 V). The greatly improved overall performance is due to the synergetic effect of the novel designed oxygen electrode capable of mediating the redox mediators to trigger the ORR and OER process.

锂空气电池在当前的电池技术中具有较高的理论能量密度，并且有望成为电动汽车的驱动力。然而，锂空气电池的实际应用因其循环寿命差，过充电电位高和能量效率低而受到限制。已经进行了许多研究来改善电化学反应的动力学。制作良好的氧还原反应（ORR）和氧释放反应（OER）催化剂体系受到严格审查。在这项工作中，我们报告了空气电极的合理设计，该电极源自生物质，并提出了具有高比表面积和大体积膨胀系数的三维多孔碳结构。结合可溶性催化剂，该氧电极具有7.95 mAh / cm2的超高面积比容量，长达1000个循环的长循环寿命，且极化得到抑制（约0.46 V）。整体性能的极大提高归因于新颖设计的氧电极的协同作用，该氧电极能够介导氧化还原介体以触发ORR和OER过程。