Recent advances in perovskite oxide electrocatalysts for Li–O₂ batteries

Abstract

Lithium-oxygen batteries (LOBs) have been anticipated as promising energy-storage devices; however, their practical application is plagued by low energy efficiency, small capacity, and the short cycle life. When applied as...

Tuning the Oxygen Reduction Reactivity of Layered Perovskites Using the Jahn–Teller Effect

“…Previous analysis of cobaltate and manganate perovskites have shown that local changes in bond lengths, a feature that often affects XRD patterns by broadening Bragg peaks, permits growth of such symmetry-forbidden peaks in Raman spectra by disrupting lattice symmetry. − The observed changes in Raman spectra and unit cell dimensions can be understood as a replacement of Ni(III), a d 7 ion, with Co(III), a d 6 ion. This substitution contracts the c axis by removing electron density from antibonding orbitals, which is known to affect both OER and ORR according to the Sabatier principle by altering B–O bond strength. ,, The substitution also replaces an ion expected to exhibit strong Jahn–Teller expansion of B–O ax bonds with one that would prefer no expansion (Figure A), which will alter the strain distribution in the lattice. These structural changes can be confidently attributed to alteration of bonding rather than oxygen defects because oxygen stoichiometry has been shown to be insensitive to y in La 2– x Sr x Ni 1– y Co y O 4 .…”

“…This substitution contracts the c axis by removing electron density from antibonding orbitals, which is known to affect both OER and ORR according to the Sabatier principle by altering B−O bond strength. 1,43,44 The substitution also replaces an ion expected to exhibit strong Jahn−Teller expansion of B−O ax bonds with one that would prefer no expansion (Figure 6A), which will alter the strain distribution in the lattice. These structural changes can be confidently attributed to alteration of bonding rather than oxygen defects because oxygen stoichiometry has been shown to be insensitive to y in La 2−x Sr x Ni 1−y Co y O 4 .…”

Modulation Strategies and Activity Descriptors of Spinel Electrocatalysts for Lithium−Oxygen Batteries

“…However, film‐like Li 2 O 2 tends to completely cover the cathodic surface, unfavorable to the continued growth of discharge products, resulting in poor LOBs discharge capacity. In contrast, the toroidal Li 2 O 2 possesses less contact area with the cathodic surface but larger voids, thus the corresponding LOBs exhibit larger discharge capacity but higher overpotential [72–74] . As a result, a rational design of high‐efficiency cathode catalysts is essential to control the reversible formation of discharge products.…”

“…In contrast, the toroidal Li 2 O 2 possesses less contact area with the cathodic surface but larger voids, thus the corresponding LOBs exhibit larger discharge capacity but higher overpotential. [72][73][74] As a result, a rational design of high-efficiency cathode catalysts is essential to control the reversible formation of discharge products.…”

A facile coprecipitation approach for synthesizing LaNi0.5Co0.5O3 as the cathode for a molten-salt lithium–oxygen battery

“…20 The LaNiO 3 perovskite is one of the most widely investigated catalytic materials for various electrochemical applications. 23 Porous LaNiO 3 nanocubes were first employed as the cathode catalyst in a LOB in 2014. 24 With this catalyst, the charge overpotential was reduced by up to 0.35 V at 0.08 mA cm −2 .…”