Embedded Growth of Li₂O₂ Achieved by a Rational Designed Three‐Dimensional Fe₂O₃@CNS‐CNTs Sandwich Structure for Improving the Performance of Li–O₂ Batteries

Abstract

Realizing confined Li2O2 growth and enhanced decomposition kinetics is still a challenge for lithium–oxygen (Li–O2) batteries, which influences its electrochemical performances. Herein, a three‐dimensional (3D) porous sandwich cathode architecture constructed through the self‐assembly of the in situ growing Fe2O3 nanorods on graphitic carbon nitride nanosheets (CNS) together with carbon nanotubes (CNTs) (Fe2O3@CNS‐CNTs) is presented. The formation of Fe–N structure can offer the active sites for the oxygen reduction reaction (ORR) and Fe2O3 nanorods provide the nucleation sites for the growth of Li2O2. Due to the 3D sandwich structure, the Li2O2 nanosheets can be deposited in the inner space of the 3D structure with an embedded mode, which confines the size and distribution of Li2O2. This work offers more possibilities for the realization of the controllable Li2O2 deposition, holding great promise in enlightening the hybrid cathode design for Li–O2 batteries.

Interfacial Engineering of Co3O4/Fe2O3 Nano‐Heterostructure Toward Superior Li‐O2 Batteries

“…As for the high-resolution Fe 2p spectra shown in Figure 2e, the two peaks at ≈713 and ≈724 eV for the Fe 2 O 3 and Co 3 O 4 /Fe 2 O 3 are attributed to the Fe 2p 3/2 and Fe 2p 1/2 signal, respectively, while the peak at 718.6 eV corresponds to the satellite peak. [27,28] There are three deconvoluted peaks at the 529.8, 531.3, and 532.6 eV in the O 1s XPS spectra of Fe 2 O 3 , Co 3 O 4 , and Co 3 O 4 /Fe 2 O 3 catalysts, corresponding to the lattice oxygen, oxygen vacancy, and surface adsorption oxygen, respectively (Figure 2f). [29,30] Besides, more oxygen vacancy is also indicated in Co 3 O 4 /Fe 2 O 3 based on the peak area, in accordance with the results from the Co 2p XPS spectra (Figure 2d).…”