Investigation of Cr₂O₃as Anode Materials for Lithium-Ion Batteries by Electrochemical Impedance Spectroscopy

Abstract

As a promising anode material for Li-ion batteries, pristine Cr 2 O 3 powder shows poor cycling performance due to its low electrical conductivity, the unstable of SEI film and large volume change during cycling. To better understand these problems, anode material Cr 2 O 3 /C composite is prepared by high-temperature solid-state reaction, the lithiation mechanisms of the commercial Cr 2 O 3 and Cr 2 O 3 /C composite electrodes have been investigated by electrochemical impedance spectroscopy (EIS), respectively. It is found that at the thermodynamic equilibrium voltage for the conversion reaction, the Nyquist plots of the commercial Cr 2 O 3 and Cr 2 O 3 /C electrodes both consist of three semicircles and an inclined line, and the three semicircles are ascribed to the Li ion migration through the surface film, the electronic properties of the material, and a charge transfer step, respectively. Furthermore, an equivalent circuit including elements related to the electronic and ionic transport as well as the charge transfer process is put forward to simulate the experimental EIS data. Variations of kinetic parameters for lithiation of Cr 2 O 3 as a function of potential in the initial discharge process are discussed in detail, and the reasonable explanation is given.

Cr2O3/carbon nanosheet composite with enhanced performance for lithium ion batteries

“…16,17 Many strategies have been used to solve these problems, including the preparation of nanomaterials, mesoporous materials, and carbon composites. [18][19][20][21][22] Among these strategies, carbon composites has been widely studied since carbon could not only cushion the stress from volume change of active materials and maintain the structure integrity of electrode during cycles, but also prevent the agglomeration metal oxide nanoparticles. Ya Fu et al 23 have prepared Cr 2 O 3 /carbon nanocomposites by directly carbonizing the glycine-CrCl 3 gel precursor and the prepared Cr 2 O 3 nanoparticles were embedded in carbon sheets which exhibit superior cycling and rate performances than pure Cr 2 O 3 as lithium-ion battery anode materials.…”

Investigation on the Voltage Hysteresis of Mn3O4 for Lithium-Ion Battery Applications

“…The capacitance components of the double layer and the Li 2 O/Mn composite are represented by the constant phase elements (CPEs) of CPE ct and CPE com , respectively. CPE diff is used to describe the capacitance of complex diffusion and reaction for LFL. − …”

Low temperature oxidation synthesis of carbon encapsulated Cr2O3 nanocrystals and its lithium storage performance

“…S3). In comparison to the commercial bare Cr 2 O 3 , 19 the Cr 2 O 3 @C anode exhibits a good cyclic retention at 0.1 mA cm À2 (119 mA g À1 ) and retains a reversible capacity of 397 mAh g À1 after 50 cycles. At higher current densities, a reversible capacity of 389, 313, 229, 222 and 193 mAh g À1 after 50 cycles is achieved at 0.2, 0.5, 1.0, 1.5 and 2.0 mA cm À2 (1748 mA g À1 ), respectively.…”