A hierarchical 3D carbon nanostructure for high areal capacity and flexible lithium ion batteries

A unique hierarchical three dimensional (3D) flexible current collector, in which the vertically aligned carbon nanotube (VACNT) array grown directly on carbon cloth (CC), has been developed for flexible lithium ion batteries (LIBs). This novel architecture offers a high surface area, high electronic conductivity and robust structural stability for electrochemical active materials loading. When combined with high capacity Si, the VACNT-Si/CC electrode exhibits high areal capacity together with excellent Li storage performance. Specifically, the electrode could deliver a high reversible areal capacity up to 3.33 mAh/cm2 (the corresponding specific capacity contribution from Si is as high as 2266 mAh/g) and excellent cycle performance (a capacity retention rate of 94.4% up to 200 cycles) and excellent rate capability (55.3% of the original capacity retained even when the current increased to 25 times of the original).