Two-Dimensional NiO@C-N Nanosheets Composite as a Superior Low-Temperature Anode Material for Advanced Lithium-/Sodium-Ion Batteries

Most of the anodes used in lithium-/sodium-ion batteries (LIBs/SIBs) have poor low-temperature (LT) performances, which severely limit their applications under LT environment. Herein, two-dimensional nickel oxide nanosheet encapsulated in N-doped carbon coated layer (abbreviated as NiO@C-N NSs) is successfully prepared and investigated for the first time as a LT anode for LIBs/SIBs. As a result, the prepared NiO@C-N NSs electrode delivers a high room temperature (RT) Li-storage capacity (1036 mA h g(-1)at 0.05 A g(-1)) and excellent LT Li-storage performance (428 mA h g(-1)at 0.05 A g(-1)at -40 degrees C). Furthermore, the prepared NiO@C-N NSs also exhibits a superior RT Na-storage capacity of 529 mA h g(-1)at 0.05 A g(-1)and superior LT Na-storage performance. Through electrochemical impedance spectroscopy analysis, we find that the LT Li-/Na-storage performances of NiO@C-N NSs electrodes are mainly dominated by theR(SEI)of SEI membrane formation at the electrode/electrolyte interface. Moreover, the LT Li-/Na-storage properties of NiO@C-N NSs can be effectively improved by using commercial LT electrolyte with low viscosity and low melting point.