Carbon nanoflakes as a promising anode for sodium-ion batteries

The sharp increase in the cost of lithium resource has driven the research on sodium-ion batteries (SIBs) as sodium shares a similar electrochemical property as lithium. Carbonaceous materials are important anodes for rechargeable batteries, but the prevailing graphite only shows a limited activity towards sodium storage. Herein, we demonstrate that carbon nanoflakes serve as an efficient anode material for SIBs, exhibiting a stable capacity of 148 mAh g(-1) over 600 continuous cycles at 150 mA g(-1) and an excellent rate capability of 120 mAh g(-1) at 1500 mA g(-1). More importantly, sodium storage in carbon nanoflakes exhibits a pseudocapacitive behavior, possibly due to their larger interlayer spacing and less-ordered structure vs. crystallized carbon.