Synthesis of Ni-Rich Layered-Oxide Nanomaterials with Enhanced Li-Ion Diffusion Pathways as High-Rate Cathodes for Li-Ion Batteries

Abstract

Ni-rich LiNi0.6Co0.2Mn0.2O2 nanomaterials with a high percentage of exposed {010} facets have been prepared by surfactant-assisted hydrothermal synthesis followed by solid-state reaction. Characterization by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) confirmed that the particles have enhanced the growth of nanocrystal planes in favor of Li-ion diffusion. Electrochemical tests show these cathode materials endow a large Li-ion diffusion coefficient, which leads to a superior rate capability and cyclability, suggesting these cathode materials are highly beneficial for practical application in Li-ion batteries.

A Review of Degradation Mechanisms and Recent Achievements for Ni‐Rich Cathode‐Based Li‐Ion Batteries

“…Microstructural modification toward Ni‐rich cathodes also includes studies on fabricating particles with other unique morphologies. [ 128 ] For example, Wang and co‐workers presented a 3D flower‐like hierarchical NCM622 cathode material by making use of a self‐assembling synthesis process, as exemplified in Figure 23d. [ 127 ] TEM measurements confirm that the side‐wall of the primary particle is the active (010) plane, contributing to the faster ionic transport kinetics.…”

“…Also, in some cases, the particles with novel morphology may lead to a higher degree of transition metal ion dissolution and lower tap density because of a higher specific surface area. [ 128 ]…”

Reduction of Capacity Fading in High-Voltage NMC Batteries with the Addition of Reduced Graphene Oxide

“…This disordered orientation promotes intergrain stresses at the grain boundaries and invokes deterioration with volume expansions/contractions that are experienced during the lithiation/delithiation processes. This facilitates the development of NMC811 particle cracking, which ultimately leads to inferior electrochemical performance [ 27 , 28 ]. Thus, from the cycle stability test results, we deduce that the addition of rGO retards the degradation (i.e., cracking and deformation), which occurs in NMC811 under high-voltage operation.…”

Ni-Rich Layered Oxide with Preferred Orientation (110) Plane as a Stable Cathode Material for High-Energy Lithium-Ion Batteries

“…Additonally, EDS mapping signals of Ni, Co, Mn, and all elements ( Figure 2 g) verify that all elements are uniformly distributed. It is worth noting that the thickness difference between the NCM622 and precursor nanosheet is associated with the merging of the multilayer boards during the high-temperature reaction [ 41 ]. The unique hierarchical structure is not only effectively forms good penetration of electrolytes, but also markedly increases the transport pathway for Li-ion diffusion during the delithiation/lithiation processes.…”

“…Wu and co-workers verified that it was beneficial to enhance the electrochemical performance by synthesizing fusiform hierarchical particles with exposing (110) plane [ 40 ]. Moreover, the work of Notten’s research examined that it was beneficial to enhance the rate performance by exposing the more active {010} facets, which could afford the fast Li + ion transmission rate [ 41 ]. Take all the above factors into account, synthesizing nanostructured materials with preferential orientation crystal planes will dramatically improve the poor kinetics, moderate the voltage drops and achieve superior charge/discharge performance.…”