Chromium(III) oxide carbon nanocomposites lithium-ion battery anodes with enhanced energy conversion performance

Abstract

The chromium (III) oxide (Cr 2 O 3 ) nanoparticles embedded in the carbon sheets are fabricated by combining a sol-gel approach with an efficient carbonization process using glycine as carbon precursor. These Cr 2 O 3 /carbon nanocomposites serving as anode materials for lithium-ion batteries (LIBs) have been tested, exhibiting higher cycling (reversible capacity of 465.5 mAh g -1 after 150 cycles at a current density of 100 mA g -1 ) and rate performances (the discharge capacities of 448.7, 287.2, and 144.8 mAh g -1 at a current density of 200, 400, and 800 mA g -1 , respectively) than pure Cr 2 O 3 (reversible capacity of 71.2 mAh g -1 after 150 cycles at a current density of 100 mA g -1 and the discharge capacities of 174.4, 60.5, 29.5, and 13.6 mAh g -1 at a current density of 100, 200, 400, and 800 mA g -1 , respectively) due to the presence of carbon sheets, which efficiently buffer the volume change during the lithiation/delithiation and improve the electrical conductivity between Cr 2 O 3 nanoparticles.

Facile synthesis of amorphous Cr2O3/N‐doped carbon nanosheets and its excellent lithium storage property

“…Two broad peaks related to the disordered carbon (D band, 1352 cm −1 ) and graphitized carbon (G band, 1594 cm −1 ) are observed. The intensity ratio (I D /I G ) of the two peaks is 1.4 by fitting the D and G band, indicating the low graphitization degree . The result further conforms the amorphous state of the carbon in the a ‐Cr 2 O 3 /NC.…”

“…The N 1s XPS spectrum of product is presented in Figure D. The peaks around 398 eV and 400 eV illustrate the existence of ‐N= (398.0 eV) and ‐NH‐ (400.2 eV), indicating that N‐doping carbon composites are obtained in the a ‐Cr 2 O 3 /NC.…”

“…Among these methods, the preparation of Cr 2 O 3 /carbon composite has been widely investigated, in which carbon can not only improve the electroconductivity of active materials and facilitate the transportation of lithium ions and electrons, but also cushion the stress from volume expansion of active materials and prevent the aggregation and pulverization of nanoparticles . Furthermore, as reported in many literatures, N‐doping can improve electrochemical performances of metal oxides/carbon composite. Xu et al prepared N‐doped carbon‐coated TiO 2 coaxial nanofibers, which exhibit superior features with a reversible capacity of 284 mAh g −1 after 100 cycles at 0.1 A g −1 .…”

Reversible High Capacity and Reaction Mechanism of Cr2(NCN)3 Negative Electrodes for Li‐Ion Batteries

“…inset in Figure a). The minor peaks below 0.3 V are probably due to some (de)intercalation of lithium ions in/from the carbon matrix or to the reversible precipitation/dissolution of a polymeric product of the partial decomposition of the electrolyte (vide infra).…”

“…However, the low electrical conductivity, the unstable SEI film, and the large volume change during cycling have hindered its possible application as an anode material. To overcome these issues, many researchers have turned to more sophisticated and therefore expensive approaches such as surface‐modified Cr 2 O 3 and also Cr 2 O 3 /carbon composites to improve its electrochemical performance . This work shows that the electrochemical mechanism of the reaction of Cr 2 (NCN) 3 with lithium is completely different from that of its oxide analogue, and how this difference influences its performances in lithium batteries.…”