Surface Engineering of Fluorinated Graphene Nanosheets Enables Ultrafast Lithium/Sodium/Potassium Primary Batteries

Abstract

Fluorinated carbon (CFx) is considered as a promising cathode material for lithium/sodium/potassium primary batteries with superior theoretical energy density. However, achieving high energy and power densities simultaneously remains a considerable challenge due to the strong covalency of the C‐F bond in the highly fluorinated CFx. Herein, an efficient surface engineering strategy combining surface defluorination and nitrogen doping enables fluorinated graphene nanosheets (DFG‐N) to possess controllable conductive nanolayers and reasonably regulated C‐F bonds. The DFG‐N delivers an unprecedented dual performance for lithium primary batteries with a power density of 77456 W kg−1 and an energy density of 1067 Wh kg−1 at an ultrafast rate of 50 C, which is the highest level reported to date. The DFG‐N also achieved a record power density of 15256 and 17881 W kg−1 at 10 C for sodium and potassium primary batteries, respectively. The characterization results and density functional theory calculations demonstrate that the excellent performance of DFG‐N is attributed to surface engineering strategies that remarkably improve electronic and ionic conductivity without sacrificing the high fluorine content. This work provides a compelling strategy for developing advanced ultrafast primary batteries that combine ultrahigh energy density and power density.This article is protected by copyright. All rights reserved

Ultrathin, Mechanically Robust Quasi-Solid Composite Electrolyte for Solid-State Lithium Metal Batteries

“…Furthermore, the inset in Figure b illustrates the interfacial coherence between the SEO-QSCE and the metallic lithium electrode. The initial impedance spectra of the interface display semicircular patterns in the high-frequency regions, which is an indicator of the charge-transfer impedance ( R ct ) . Remarkably, the value of R ct for the SEO-QSCE before and after polarization is measured at 51 and 50 Ω, respectively.…”

“…The initial impedance spectra of the interface display semicircular patterns in the high-frequency regions, which is an indicator of the chargetransfer impedance (R ct ). 50 Remarkably, the value of R ct for the SEO-QSCE before and after polarization is measured at 51 and 50 Ω, respectively. The calculated area resistance between SEO-QSCE and the Li sheet is 39.3 Ω cm 2 .…”

Defect Strategy in Solid‐State Lithium Batteries

“…[24] In recent years, it has been found that adding defects in the electrodes can improve conductivity, cycle stability, and rate performance. [38] Chang and coworkers [39] used first-principles method to study the insertion and diffusion behavior of lithium ion in TiO 2 with and without oxygen deficiencies. The narrowing of the bandgap and the shift of the Fermi level indicate that the electronic conductivity increases after the introduction of oxygen vacancies.…”

Topological Engineering Electrodes with Ultrafast Oxygen Transport for Super‐Power Sodium‐Oxygen Batteries

“…Constructing a true GDE is relatively straightforward in aqueous electrolytes, where hydrophobic components like polytetrafluoroethylene can be used to create a solid-gas-electrolyte three-phase interface. [34][35][36] However, in non-aqueous electrolytes, the lack of solvent-phobic components makes it challenging to construct a true GDE. Consequently, the porous electrodes in non-aqueous-based metal-air batteries are often flooded with electrolytes and deprived of efficient pathways for gas mass transport, resulting in low current densities.…”