An Anode Material for Lithium‐Ion Batteries Based on Oxygen‐Deficient Perovskite Sr₂Fe₂O_6−δ

Abstract

The application of oxygen-deficient perovskites as anode for lithium-ion batteries has been explored through case study of Sr 2 Fe 2 O 6 À δ . The structure of this material was studied through Rietveld refinements with X-ray diffraction data, while X-ray photoelectron spectroscopy and iodometric titration were utilized to determine the oxidation state of the transition metal and the degree of oxygen-deficiency. As anode, Sr 2 Fe 2 O 6 À δ delivers discharge capacity of 393 mAh g À 1 at a current of 25 mA g À 1 after 50 cycles. This capacity is higher than the theoretical capacity of graphite anode, 372 mAh g À 1 . It is also higher than that of the calcium-analogue reported before. At different current densities from 25-500 mA g À 1 , the chargedischarge cycles remain highly reversible, indicating the great potential of Sr 2 Fe 2 O 6 À δ for application as anode for lithium-ion batteries. The mechanism of lithium intercalation and deintercalation has been discussed.

Thermal Conductivity of CaSrFe2O6-δ

“…Perovskite oxides have garnered considerable attention in recent years due to their versatile properties, which make them promising candidates for a variety of technological applications, including thermoelectric devices [1], catalysis [2], and energy storage systems [3]. Among these oxides, CaSrFe2O6-δ stands out as an oxygen-deficient perovskite with a brownmillerite structure and intriguing electronic and structural features that render it an interesting subject for investigation [4].…”

The Crystal Structure Study of CaSrFe<sub>0.75</sub>Co<sub>0.75</sub>Mn<sub>0.5</sub>O<sub>6−<i>δ</i></sub> by Neutron Diffraction

“…[4] [5] Due to these properties, perovskite oxides find applications in various fields, including electronics, catalysis, and energy storage. Perovskite oxides are recently the focus of research because of their potential applications in technology such as solid oxide fuel cells, [6] metal-air batteries, [7] Lithium battery, [8] electrocatalysis, [9] thermal insulation, [10] sensors, [11] and photovoltaics. [12] Oxygen plays an important role for the material to demonstrate a functional property, leading to exhibit excellent catalytic behavior in many tran-sition-metal oxides.…”

Specific Heat Capacity of A<sub>2</sub>FeCoO<sub>6-<i>δ</i></sub> (A = Ca or Sr)

“…They are oxygen-deficient perovskites. Because of their unique properties, oxygen-deficient perovskite oxides can be used in a variety of devices including gas diffusion membranes, [1] oxygen separation ceramic membranes [2], solid oxide fuel cells (SOFCs), [3] electrodes, [4] sen-sors, [5] superconductors, and colossal magnetoresistance. [6] Oxygen-deficient perovskites are the oxides with lanthanides or alkali metals in their A site and 3d and 4d-transition metal in their B site in the general formula ABO 3−x or A 2 B 2 O 6−δ .…”