Li-cycling properties of nano-crystalline (Ni1 − x Zn x )Fe2O4 (0 ≤ x ≤ 1)

Abstract

Sol-gel auto-combustion method is adopted to prepare solid solutions of nano-crystalline spinel oxides, (Ni 1−x Zn x )Fe 2 O 4 (0≤x≤1).The phases are characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy, selected area electron diffraction, and Brunauer-Emmett-Teller surface area. The cubic lattice parameters, calculated by Rietveld refinement of XRD data by taking in to account the cationic distribution and affinity of Zn ions to tetrahedral sites, show almost Vegard's law behavior. Galvanostatic cycling of the heat-treated electrodes of various compositions are carried in the voltage range 0.005-3 V vs. Li at 50 mAg −1 up to 50 cycles. Phases with high Zn content x≥0.6 showed initial two-phase Li-intercalation in to the structure. Second-cycle discharge capacities above 1,000 mAh g −1 are observed for all x. However, drastic capacity fading occurs in all cases up to 10-15 cycles. The capacity fading between 10 and 50 cycles is found to be greater than 52% for x≤0.4 and for x00.8. For x00.6 and x01, the respective values are 40% and 18% and a capacity of 570 and 835 mAh g −1 is retained after 50 cycles. Cyclic voltammetry and ex situ transmission electron microscopy data elucidate the Li-cycling mechanism involving conversion reaction and Li-Zn alloying-dealloying reactions.

Mixed Oxides, (Ni1–xZnx)Fe2O4 (x = 0, 0.25, 0.5, 0.75, 1): Molten Salt Synthesis, Characterization and Its Lithium-Storage Performance for Lithium Ion Batteries

“…CVs of cathodic and anodic curves after 50 cycles (S.I. 2 a-e) showed minor differences in the peak potentials.The main peak potentials observed are similar to those obtained in literature studies21 .…”

Facile Synthesis of NiFe2O4/Reduced Graphene Oxide Hybrid with Enhanced Electrochemical Lithium Storage Performance

“…The good cycling stability of NFO/rGO can be ascribed to the following factors: (1) rGO can tightly immobilize the active particles even though pulverization occurs; (2) the high Li-ion/electronic conductivity of rGO makes it possible for rapid electrochemical reactions at high current densities; (3) both the free space and rGO in the hybrid provide buffering effect for the volume changes. The electrochemical performance of our NiFe 2 O 4 /rGO is better than those of NiFe 2 O 4 samples which usually exhibited rapid capacity fade without carbon support [34,35] , and is comparable with or superior to those using carbon matrix considering the applied current density [29,37] . Note that although CNTs addition could significantly improve the electrochemical performance of NiFe 2 O 4 , the synthesis of NiFe 2 O 4 /CNTs involved the use of costly precursors and a relatively complicated procedure [39] .…”

Anodic electrochemical performances of MgCo 2 O 4 synthesized by oxalate decomposition method and electrospinning technique for Li-ion battery application

“…Form the second cycle onwards the CV curves are almost the same when compared to the CV curves of MgCo 2 O 4 by oxalate method, showing the good electrochemical reversibility. The main peak cathodic and anodic peak potentials other spinel oxides [4,6,9,10,43,44] and broad peaks (Fig. 7a) in the CV is due to differences in the crystallinity of MgCo 2 O 4 material.…”