Long cycle life of CoMn₂O₄ lithium ion battery anodes with high crystallinity

Abstract

CoMn 2 O 4 nanomaterials are prepared by a low temperature precipitation route employing metal acetates and NaOH. Structural changes, induced by different annealing temperatures, are comprehensively analyzed by X-ray powder diffraction and Raman spectroscopy. With rising annealing temperature the crystal lattice of CoMn 2 O 4 undergoes changes; AO 4 tetrahedra expand due to thermally induced substitution of Co 2+ by larger Mn 2+ metal ions on the A-site of the spinel structure, while in contrast, BO 6 octahedra shrink since the B-site becomes partially occupied by smaller Co 3+ metal ions on account of the migrated Mn ions. CoMn 2 O 4 particle sizes are easily fine-tuned by applying different annealing temperatures; the particle size increases with increasing annealing temperature. During the battery operation, pulverization and reduction of particle sizes occurs regardless of the initial size of the particles, but the degree of division of the particles during the operation is dependent on the initial particle properties. Thus, contrary to the common assumption that nanostructuring of the anode material improves the battery performance, samples with the largest particle sizes exhibit excellent performance with a capacity retention of 104% after 1000 cycles (compared to the 2 nd cycle).

Raman study of Ming porcelain dark spots: Probing Mn‐rich spinels

“…Even if specific crystal orientations cannot be selected here, polarized Raman spectra provide relevant information regarding symmetry. Worthy of mention, selection rules for spectrum (d) in Figure are similar to the ones of the upper set in Figure as expected, CoMn 2 O 4 having also tetragonal spinel structure . Thus, simply recording polarized Raman spectra provides a reliable means to discriminate between jacobsite‐like and hausmannite‐like spinels.…”

“…Furthermore, spectrum (d) also exhibits some similarities with spectra reported for CoMn 2 O 4 . Indeed, CoMn 2 O 4 Raman spectrum displays a characteristic doublet peak in the 315‐ to 380‐cm −1 range and strong peak at 661 cm −1 .…”

Controlled synthesis of CoxMn3−xO4 nanoparticles with a tunable composition and size for high performance lithium-ion batteries

“…They showed that although conversion redox process led to the break and reduction of oxide crystallites during the cycles, there is an superiority to start with initially larger particles, which is conductive to the better state of division of the metal particles upon reduction and hence the enhanced capacity retention of the electrode materials. 35,48 However, they also suggest that, if the particles are too big, a lower stable capacity is obtained. Existence of an optimal particle size for an optimal battery performance has been subsequently demonstrated for ZnMn 2 Conclusions Co x Mn 3-x O 4 nanomaterials with tunable composition and size were prepared using a solvothermal method to generate a bimetal coordination-polymer (Co x Mn 3-x -BTC) as the precursor, and then followed by a post-annealing treatment.…”

“…The majority of existing work on battery performance appears to focus on the complex morphologies of the synthesized Co x Mn 3-x O 4 anode materials, in contrast with the exceedingly rare reports of crystal structures. 35 Accordingly, we undertaken a careful investigation of the effect of different calcinating temperatures on crystallinity and its consequence for subsequent the performance.…”

Probabilistic Prediction Algorithm for Cycle Life of Energy Storage in Lithium Battery

“…The research and development of power batteries with high energy density and long cycle life have become hot issues in the field of electric vehicle (EV). Based on the current research progresses and the accumulation of experience, lithium batteries with capacities above 300 Wh/kg can be realized [1,2]. However, at a specific point in time, the problem of energy storage will be inevitably encountered, i.e., the battery performance will continue to decline with the cycling and material aging until the battery is discarded [3].…”