Self-standing heterostructured NiC_x-NiFe-NC/biochar as a highly efficient cathode for lithium–oxygen batteries

Abstract

Lithium–oxygen batteries have attracted research attention due to their low cost and high theoretical capacity. Developing inexpensive and highly efficient cathode materials without using noble metal-based catalysts is highly desirable for practical applications in lithium–oxygen batteries. Herein, a heterostructure of NiFe and NiC x inside of N-doped carbon (NiC x -NiFe-NC) derived from bimetallic Prussian blue supported on biochar was developed as a novel self-standing cathode for lithium–oxygen batteries. The specific discharge capacity of the best sample was 27.14 mAh·cm−2 at a stable discharge voltage of 2.75 V. The hybridization between the d-orbital of Ni and s and p-orbitals of carbon in NiC x , formed at 900 °C, enhanced the electrocatalytic performance due to the synergistic effect between these components. The structure of NiC x -NiFe-NC efficiently improved the electron and ion transfer between the cathode and the electrolyte during the electrochemical processes, resulting in superior electrocatalytic properties in lithium–oxygen batteries. This study indicates that nickel carbide supported on N-doped carbon is a promising cathode material for lithium–oxygen batteries.

Ni–Co Prussian blue analogue/graphene aerogel: a green synthesis approach for high-performance electromagnetic wave absorption and radar stealth applications

“…3d, the N 1s peak of 398.5 eV belongs to the CN bond of Ni–Co PBA. 44 As for the metallic elements of Ni–Co PBA, the typical peaks of Co 2p are observed at 782.3 eV for 2p 3/2 and 797.2 eV for 2p 1/2 (Fig. 3e), and Ni 2p shows the typical peaks of 857.3 eV for 2p 3/2 , 875.0 eV for 2p 1/2 and two satellite peaks (Fig.…”

Stable polyethylene glycol/biochar composite as a cost-effective photothermal absorber for 24 hours of steam and electricity cogeneration

“…2c and revealed that the major surface functional groups were C–C, CC, and CO around 284.7, 285.2, and 286.5 eV, respectively. 17,75,76 The O1's distinct peaks are depicted in Fig. 2d, which demonstrated that its main functional groups were O–C, OC, and O–H at 531.5, 532.9, and 534 eV, respectively.…”

“…2d, which demonstrated that its main functional groups were O–C, OC, and O–H at 531.5, 532.9, and 534 eV, respectively. 17,76…”

Simple Synthesis and Characterization of Shell-Thickness-Controlled Ni/Ni3C Core-Shell Nanoparticles

“…The BE of 860.2 eV is characteristic of related satellite peaks. The slightly lower BE of 854.5 eV is assigned to partially reduced nickel species with a positive charge δ+ (Ni δ+ ), indicative of the presence of a nickel carbide phase [30][31][32][33]. As the synthesis time increases, the ratio of this peak to the 2+ peak gradually increases, indicating that the ratio of nickel carbide in the powder increases.…”