Investigation of carbon fiber anode materials for collector-free lithium-ion batteries[Study on modification methods to improve Li-ion storage capacity of carbon black]

Lithium-ion batteries (LIBs) play a key role in grid-scale energy storage, making the development of LIBs with higher gravimetric energy density a necessity. Reducing the mass of the inactive collector component or even removing the collector altogether is important for improving energy density. This work proposes a 3D network electrode constructed based on the linear structure of carbon fiber (CF), which is directly used as an anode material without using a copper foil collector, and compared with the existing graphite anode material. The results show that CF has better rate performance, and the specific capacity of CF at high loading (1.3 mg/cm2) increases to a different degree along with the initial cycle. The comprehensive performance of the full battery assembled with CF electrode as the anode and LiFePO4 as the cathode shows that its overall energy density is higher than that of the graphite/LiFePO4 battery. The energy densities of CF/LiFePO4 and Graphite/LiFePO4 after 10 cycles at 0.1A/g current density were 198.7 Wh/kg and 132.7 Wh/kg, respectively. The energy density and power density of CF/LiFePO4 at other current densities are also greater than those of Graphite/LiFePO4.