Highly Reduced Graphene Assembly Film as Current Collector for Lithium Ion Batteries
Yuwei Zhao, Jinlong Yang, Jingjing Ma, Qian Wu, Wei Qian, Zhe Wang, Haining Zhang, Daping He, Shichun Mu
Abstract
With the development of lithium ion batteries (LIBs), further increasing the energy densities of batteries is urgent. Graphene, with excellent chemical stability, high conductivity, and light weight, is an ideal material to improve the battery energy density by replacing traditional metal current collectors. Accordingly, we report a large-size (120 mm × 120 mm) graphene assembled film (GAF) with high crystallinity, electrical conductivity ((2.30 ± 0.06) × 105 S m–1) and ultralight weight (3.18 mg cm–2). The electrode/GAF interface has better wetting and lower contact resistance. When all the metal (Al/Cu) current collectors are replaced by GAF, the energy density of the full cell electrode can increase by 32.9% (with an areal density of 4 mAh cm–2). Moreover, the electrode with GAF current collectors shows improvements in cycling stability, rate capability, and capacity. Undoubtedly, these results suggest that GAF has broad prospects as a high-energy-density lithium ion current collector.