Fluorinated graphene nanoribbons from unzipped single-walled carbon nanotubes for ultrahigh energy density lithium-fluorinated carbon batteries

Abstract

Lithium-fluorinated carbon (Li-CF x) batteries have become one of the most widely applied power sources for high energy density applications because of the advantages provided by the CF x cathode. Moreover, the large gap between the practical and theoretical potentials alongside the stoichiometric limit of commercial graphite fluorides indicates the potential for further energy improvement. Herein, monolayer fluorinated graphene nanoribbons (F-GNRs) were fabricated by unzipping single-walled carbon nanotubes (SWCNTs) using pure F 2 gas at high temperature, which delivered an unprecedented energy density of 2738.45 W h kg −1 due to the combined effect of a high fluorination degree and discharge plateau, realized by the abundant edges and destroyed periodic structure, respectively. Furthermore, at a high fluorination temperature, the theoretical calculation confirmed a zigzag pathway of fluorine atoms that were adsorbed outside of the SWCNTs and hence initiated the spontaneous process of unzipping SWCNTs to form the monolayer F-GNRs. The controllable fluorination of SWCNTs provided a feasible approach for preparing CF x compounds for different applications, especially for ultrahigh-energy-density cathodes.

Germanium‐based monoelemental and binary two‐dimensional materials: Theoretical and experimental investigations and promising applications

“…Rechargeable batteries are extremely effective devices for energy storage and utilization, and 2D materials are the ideal candidates for battery electrodes because of their unique nanostructures, ultrahigh specific surface areas, and high planar electronic conductivities 140,464,465 . Numerous studies have proven that 2D materials can usually store large amounts of alkali metal ions, resulting in high storage capacities 466–468 . The large and adjustable interlamellar spacing of 2D nanosheets can enhance the transmission of ions and electrons and significantly alleviate the volume expansion during the discharge and charge process 11,12,469,470 .…”

“…140,464,465 Numerous studies have proven that 2D materials can usually store large amounts of alkali metal ions, resulting in high storage capacities. [466][467][468] The large and adjustable interlamellar spacing of 2D nanosheets can enhance the transmission of ions and electrons and significantly alleviate the volume expansion during the discharge and charge process. 11,12,469,470 The high specific surface area endows them with a large number of effective active sites, thereby accelerating the electrochemical reaction process.…”

Pushing capacities and energy densities beyond theoretical limits of lithium primary batteries using active CFx nanocapsules with x > 1

“…[9][10][11] However, the complex chemistry and inactivation of CF x in certain molecular forms limit its full exploration; therefore, an in-depth understanding of the CF x mechanism of action and corresponding chemical modifications is required to make CF x the only choice for lithium primary batteries. [12][13][14][15] In this aspect, a series of fluorinated carbonaceous materials are being investigated in different geometries, such as fluorinated nanotubes, 16,17 fluorinated carbon nano-discs (CND), 18 fluorographene, 19,20 and fluorinated graphite. 21,22 Among these, the fluorographene and fluorinated CND displayed excellent performance by delivering a capacity of 1180 mA h g −1 and an energy density of 2338 W h kg −1 at 10 mA g −1 , because the reinforcement effect of the central discs and the presence of the LiF shell allowed the diffusion of lithium ions through the sheet edges or from the surface cracks.…”

Co-Existence of Iron Oxide Nanoparticles and Manganese Oxide Nanorods as Decoration of Hollow Carbon Spheres for Boosting Electrochemical Performance of Li-Ion Battery

“…Although the performance of lithium-ion batteries continues to improve, their energy density, cycle lifetime and productivity remain insufficient for large-scale applications in consumer electronics, and transportation and storage of renewable energy. Much effort has been made to create new electrode materials or to design unique electrode architecture to address the everincreasing demand for batteries with higher energy density and longer cycle life [3][4][5][6][7]. The electrodes must maintain their integrity across multiple discharge-recharge cycles, which is one of the challenges in their design.…”