Hollow Nanoporous Multishelled NiCo₂O₄ Spheres for Lithium-Ion Batteries

Abstract

Lithium-ion batteries (LIBs) have fallen short of expectation in terms of energy density compared to conventional lithium-ion batteries, and the theoretical energy density of the anode material plays a crucial role. Materials with high equilibrium effective specific surface area and mass transport could be promising to solve the dilemma. Herein, we develop a tactic to synthesize carbonaceous microspheres (CMSs, 13 μm) utilizing cobalt acetate tetrahydrate as the catalyst. Six-shelled NiCo2O4 hollow multishelled structures (6S-NiCo2O4-HoMSs) have been realized for the first time based on the alkali-treated CMS (ATCMS) template with nanoporous structures. Precisely, low-dimensional nanostructures enable more electroactive sites, smaller local current density, and shorter diffusion paths for both ions and electrons. The particular hollow multishelled structure serves to buffer the volume expansion, reduce the stress and strain to permit more uniform lithium deposition, and improve the cycle stability of the battery.

Spherical, flower-like MnCo2O4with a hollow structure as the cathode for efficient Li-CO2batteries

“…38 Co 2p spectra showed characteristic peaks centered at 779.5 eV and 794.5 eV, which corresponded to Co 2p 3/2 and Co 2p 1/2 , respectively. 39 Moreover, the Co 2p XPS spectrum could be deconvoluted into peaks centered at 779.5, 794.5, 780.6 and 795.8 eV, indicating that Co 3+ and Co 2+ were present in the sample (Fig. 5c).…”

Augmented and sustained oxygen reduction reaction activity of NiCo2O4 by the incorporation of Ag

“…5(D) exhibited four fitted peaks, which correspond to the metal-oxygen bond (O1), oxygen in the OH À group (O2), oxygen coordination defects (O3), and physisorbed/chemisorbed hydroxyl groups present at/within the interface of the catalyst (O4). 50 The Ag 3d peak deconvolution resulted in two peaks centered at 368.3 eV and 374.3 eV arising from the metallic silver, suggesting the formation of Ag nanoparticles. 51 The amount of Ag in the Ag-NiCo 2 O 4 and Ag/C catalysts was obtained from the ICP-MS analysis as 0.190% and 1.059%, respectively.…”

Intergrating Hollow Multishelled Structure and High Entropy Engineering toward Enhanced Mechano‐Electrochemical Properties in Lithium Battery

“…Rechargeable lithium batteries have been regarded as an important part of the clean energy network for achieving carbon neutrality. [1][2][3] To meet the growing demand for remarkable achievements, given the challenging synthesis strategies, most of such material designs have been focused only on mono-to ternary TMOs such as Co 3 O 4 , [12] NiCo 2 O 4 , [13] and NiCoMnO 4 . [14] Their practical application remains largely hampered by the poor reversibility of the reconversion process, the coarseness/aggregation of nanocrystals, and the low intrinsic conductivity.…”

“…Multiple shells are intersupported to provide better mechanical stability and to boost rate performance by shortening the effective diffusion distance of electrons/ions. [ 10,11 ] Despite the remarkable achievements, given the challenging synthesis strategies, most of such material designs have been focused only on mono‐ to ternary TMOs such as Co 3 O 4 , [ 12 ] NiCo 2 O 4 , [ 13 ] and NiCoMnO 4 . [ 14 ] Their practical application remains largely hampered by the poor reversibility of the reconversion process, the coarseness/aggregation of nanocrystals, and the low intrinsic conductivity.…”