Super P Carbon Modified Lithium Anode for High-Performance Li−O2 Batteries

Graphical Right off the batt : A Li@Super P composite anode with a high specific surface area is fabricated through a low-cost brushing method, which effectively decreases the interface impedance and overpotential of Li depositing/stripping. The anode can also mitigate the detrimental shuttling effect of I 3 − generated from LiI during the charging process. The combination of the protected Li anode and LiI mediator delivers superior Li−O 2 battery performance. Rechargeable Li−O 2 batteries represent a highly attractive battery technology, owing to a high theoretical energy density of 3500 Wh kg −1 , but they suffer from large charging polarization and lithium anode degradation on cycling. Herein, we report a Li−O 2 battery system with reduced polarization and a long lifespan, which is realized by using a novel Li@Super P composite anode integrated with lithium iodide in ether-based electrolyte. Coating a Super P carbon layer, with an optimal thickness of approximately 30 μm, onto the lithium anode results in a lowered interface impedance and a decreased Li depositing/stripping overpotential (<15 mV) over 300 cycles at 0.3 mA cm −2 . The Li−O 2 batteries assembled with the Li@Super P anode and LiI additive could mitigate the detrimental shuttling effect of I 3 − and deliver a high reversible capacity of 1000 mAh g −1 with a median charge voltage lower than 3.3 V after 50 cycles. This study provides a simple yet effective way to protect the lithium anode and design high-performance Li−O 2 batteries.