Fabrication of hierarchical porous MnCo₂O₄ and CoMn₂O₄ microspheres composed of polyhedral nanoparticles as promising anodes for long-life LIBs

Abstract

Uniform hierarchical porous MnCo2O4 and CoMn2O4 microspheres (3-6 µm) were fabricated through solvothermal process followed by a post annealing treatment. Fascinatingly, these porous MnCo2O4 and CoMn2O4 microspheres are composed of numerous polyhedral nanoparticles with diameters in the range of 200-500 nm. The porous structure is believed beneficial for improving the lithium-storage performance of the products, which can effectively buffer the volume expansion during Li + insertion/extraction process and shorten the Li + diffusion lengths. Polyhedral structure can enhance the electrolyte/electrode contact area and increase the Li + insertion/extraction sites. When used as anode materials for lithiumion batteries, the porous MnCo2O4 and CoMn2O4 microspheres exhibited excellent long-life cycling performance at high rate density. At current density of 1000 mA g -1 , the MnCo2O4 and CoMn2O4 exhibite initial capacity of 1034 and 1107 mAh g -1 and the capacity maintain at 740 and 420 mAh g -1 after 1000 cycles. Furthermore, the growth mechanism of porous microspheres is proposed based on many contrast experiments. The relationship between morphology evolution and annealing time is particular investigated in detail. It is find that the annealing time plays an important role to get products with different morphologies. Through controlled annealing time, porous microspheres, yolk-shell microspheres and solid microspheres could be selectively obtained.

Three-dimensional NiCo2O4 nanowire arrays: preparation and storage behavior for flexible lithium-ion and sodium-ion batteries with improved electrochemical performance

“…Based on the previous reports, the entire electrochemical process for the both electrodes can be expressed as follows: [12][13][14][15][16][17] …”

In Situ Synthesis of Mn3O4 Nanoparticles on Hollow Carbon Nanofiber as High‐Performance Lithium‐Ion Battery Anode

“…To meet the rapidly increasing demand for higher power density and energy density, advanced alternatives with higher capacity as anode materials is required. Notably, transition‐metal oxide materials have displayed promising potential because of their higher reversible capacities . Among them, Mn 3 O 4 has high theoretical capacity (2.5 times that of graphite), natural abundance, nontoxicity, and low cost; thus making it a promising anode material for high‐performance LIBs .…”

A hexangular ring–core NiCo2O4 porous nanosheet/NiO nanoparticle composite as an advanced anode material for LIBs and catalyst for CO oxidation applications

“…[4] Meanwhile, Co 3 O 4 has been one of the most promising catalysts for CO oxidation in room temperature even at low temperature. [5] However, Co 3 O 4 cannot be perfect candidate as anode material or catalyst for CO oxidation due to its toxicity and high cost, therefore，it is necessary to explore cheaper and eco-friendly alternative metals replace Co 3 O 4 partially, such as NiCo 2 O 4 , [6] CuCo 2 O 4 [7] and MnCo 2 O 4 [8] materials, which are all isostructural to Co 3 O 4 .…”