Fluorinated graphene/sulfur hybrid cathode for high energy and high power density lithium primary batteries

Abstract

It is a great challenge to obtain high performance carbon fluoride (CF x ) cathodes with high specific capacity and good rate performance due to the electronic conductivity of CF x being known to decrease with an increase in the specific capacity. Herein, we propose a novel fluorinated graphene (FG)/sulfur hybrid cathode to enhance both the energy density and power density of lithium/carbon fluoride (Li/CF x ) batteries. Impressive enhancements of the specific capacity, discharge voltage, and rate capability are demonstrated with the novel FG/sulfur hybrid cathode. In comparison with the pristine FG cathode, the hybrid cathode exhibits higher electrochemical activity, lower overpotential, and faster ion transfer over the main discharge range. Furthermore, when the melt-diffusion method is used to prepare the hybrid cathode, the uncommon monoclinic sulfur is presented under ambient temperature. A significant synergistic effect which reduces the reaction resistance effectively is demonstrated with the presence of monoclinic sulfur, leading to the highest energy density of 2341 W h kg À1 and a power density up to 13 621 W kg À1 at 8.0 A g À1 . Our results are expected to introduce a new generation of high energy and high power density lithium primary cells, based on a simple and effective strategy employing FG/S hybrid cathodes.

Facile Carbon Fluoride/Sulfur Hybrid Cathode for High‐Rate Lithium Batteries

“…In addition, a reduction peak below about 1.9 V can be observed for all three materials, resulting from the decomposition of LiNO 3 and other side reactions with the electrolyte. [8,19] During the following cycling segments, an oxidation peak onset around 2.3 V and two reduction peaks at 2.3 V and 2.0 V are observed for both samples, which are characteristic CV response of sulfur. It confirms the rechargeable ability of the CF x /S hybrid cathode.…”

“…Previously, outstanding primary discharge performances of the CF x /S cathode have been verified involving a prototype of fluorinated graphene/sulfur composite . While the discharge mechanism and the feasibility for the CF x /S material performing as a rechargeable cathode are still remain uncertain.…”

“…Previously, outstanding primary discharge performances of the CF x /S cathode have been verified involving a prototype of fluorinated graphene/sulfur composite. [8] While the discharge mechanism and the feasibility for the CF x /S material performing as a rechargeable cathode are still remain uncertain. In present study, three typical carbon fluorides, fluorinated graphene (FGR), fluorinated graphite flake (FGF), and fluorinated carbon fiber (FCF) with different morphology and fluorine content (see Table 1) are applied to fabricate CF x /S hybrid cathodes facilely through the melt-diffusion method.…”

Facile Synthesis of Solvent Sensitive Fluorinated Graphene Nanoscrolls and Application as a Cathode Material for Lithium Ion Batteries

“…In the recent year, different attempts, for example, MnO2 doped Li/C1Fx [9] , multiple-walled carbon nanotubes modified Li/C1Fx [14] , polyaniline coated Li/C1Fx [15] , conductive polymer coated Li/C1Fx [16] and modification to fluorinated graphene [17] etc., were commonly used as electrode material to improve the rate performance of fluorinated carbon materials in lithium batteries. Among which, significant attention had paid to the electrode material of fluorinated graphene [18] , which was derived from C1Fx. The electrochemical performance of the derived fluorinated graphene was significantly better than the C1Fx candidate.…”

A brief review for fluorinated carbon: synthesis, properties and applications

“…However, the low specific capacity is delivered due to an extremely small F/C ratio when the ionic C-F bond is developed only [24]. In the case of ultra-high F/C ratio, the rate performance is deteriorated because of the large number of covalent bonds resulting in a poor conductivity [25]. Thus, optimizing the composition of C-F bonds and F/C ratios is an efficient approach to obtain fluorinated carbon with high performance.…”