Structure and Electrochemistry of Copper Fluoride Nanocomposites Utilizing Mixed Conducting Matrices

Abstract

Near-theoretical utilization of high-energy-density CuF 2 positive electrode materials for lithium batteries was enabled through the use of nanocomposites consisting of 2-30 nm domains of CuF 2 within a mixed ionic + electronic conducting matrix of a metal oxide. Small but significant crystallographic changes to the core crystal of the CuF 2 were found to occur in all oxide-based matrices. These modifications to the core crystal and the surrounding matrix were investigated through a host of characterization methods, including XRD, XPS, and XAS. This new approach to the enablement of the anhydrous CuF 2 is distinctly superior in performance to that of macro CuF 2 or CuF 2 nanocomposites utilizing carbon as a matrix, the latter of which is also introduced herein for the first time.

Beyond Intercalation‐Based Li‐Ion Batteries: The State of the Art and Challenges of Electrode Materials Reacting Through Conversion Reactions

“…Such nanocomposites enable close-to-theoretical capacities, most of which is delivered at high voltages (close to 3 V). [ 271 ] Although these fi ndings are of certain interest in view of application in primary cells, reversibility of the reactions is not discussed. The reduction reaction has been recently studied by solid state NMR and XRD [ 272 ] and found to simply consist of direct formation of Cu and LiF without intermediate phases.…”

Structure and electrochemical performance of FeF3/V2O5 composite cathode material for lithium-ion battery

“…The MCM approach focuses mainly on effective transport of both ions and electrons to the metal fluoride nanodomain. It has been found that introduction of V 2 O 5 to the electro-active material can markedly enhance the electrochemical performance of the composite cathode [17,18]. Additionally, the density of V 2 O 5 is much higher than that of carbon, and the addition of V 2 O 5 is in favor of enhancing the specific energy density of cathode material.…”

Anodes – Materials for negative electrodes in electrochemical energy technology

“…A review of the use of conversion materials with particular attention to metal oxides has been provided [96]. Copper fluoride CuF 2 nanocomposites within a mixed conduction matrix have shown almost stoichiometric conversion [97].…”