正极缓慢的氧还原/析氧反应动力学限制了锂空气电池(LABs)的实际应用。开发了Te、N共掺杂MXene锚定单原子Cu(Cu_SA-Te/N-MXene)用于LABs的正极催化剂。分散的少层MXene纳米片增大了存储放电产物所需的空间,分散的Cu单原子可以有效催化放电产物的形成和分解,从而大大提高氧化还原动力学。结果表明,Cu_SA-Te/N-MXene正极表现出超高放电容量(500 mA/g电流密度下放电容量达到16 694 mAh/g)、较低的充电过电压(限定容量为1 000 mAh/g,500 mA/g电流密度下充电过电压为0.48 V)和出色的循环稳定性(500 mA/g电流密度下稳定循环425圈)。

The sluggish kinetics of the oxygen reduction/oxygen evolution reactions at the cathode limits the practical application of non-aqueous lithium-air batteries (LABs).Herein,Cu single-atom anchored on Te-N co-doped MXene (Cu_SA-Te/N-MXene) is developed as a catalyst for LABs.Dispersed few-layer MXene nanosheets increase the space required for storage of discharging products,while the dispersed Cu single atoms can effectively catalyze the formation and decomposition of discharging products,thereby significantly accelerating the electrochemical kinetics of redox processes.It is indicated that Cu_SA-Te/N-MXene cathode shows a discharge capacity as high as 16 694 mAh·g^-1 at a current density of 500 mA·g^-1,a charge overvoltage as low as 0.48 V at a current density of 500 mA·g^-1 as well as a limited capacity of 1 000 mAh·g^-1,and an excellent cycling stability that represents 425 stable cycles at a current density of 500 mA·g^-1.

王中华(1998-),男,硕士生,研究方向为新能源电池材料,wangzhonghua011@163.com;张业龙(1988-),男,博士,副教授,主要研究方向为锂空气电池,zhangyelong2008@126.com。