Fast Li-Ion Insertion into Nanosized LiMn₂O₄ without Domain Boundaries

Abstract

The effect of crystallite size on Li-ion insertion in electrode materials is of great interest recently because of the need for nanoelectrodes in higher-power Li-ion rechargeable batteries. We present a systematic study of the effect of size on the electrochemical properties of LiMn(2)O(4). Accurate size control of nanocrystalline LiMn(2)O(4), which is realized by a hydrothermal method, significantly alters the phase diagram as well as Li-ion insertion voltage. Nanocrystalline LiMn(2)O(4) with extremely small crystallite size of 15 nm cannot accommodate domain boundaries between Li-rich and Li-poor phases due to interface energy, and therefore lithiation proceeds via solid solution state without domain boundaries, enabling fast Li-ion insertion during the entire discharge process.

Aromatic porous-honeycomb electrodes for a sodium-organic energy storage device

“…3a,b) and 2.3 V versus Na/Na þ (n-doping process, Fig. 3c,d) after achieving each quasi-equilibrium state 46 in order to probe the physical and/or chemical phenomena at the interface between the BPOE and the electrolyte solution. A frequency range of 10 mHz-10 kHz with an amplitude of 10 mV was applied in all EIS measurements.…”

Evaluating the performance of nanostructured materials as lithium-ion battery electrodes

“…The boundary-less mechanism facilitated capacities of greater than 160 mA h g -1 at rates as high as 10 C, far exceeding those of bulk and larger sized (43 nm) particles [275]. Such size-effects could therefore account for the enhanced rate capability displayed by small diameter LiMn2O4 nanorods [270][271][272], and nanowires [265][266][267], which possess both high power and enhanced cycling ability.…”

“…Coupled with relatively low production costs and appreciable electrochemical performance at high discharge rates and elevated temperatures, LiMn2O4 is touted as a potential driver of future EV/HEV battery packs, notably against favourable LiFePO4 candidates [264]. Recent nanostructured morphologies of note include nanowires [265][266][267], nanorods [268][269][270][271][272], nanotubes [273], nanoparticles [269,[274][275][276] and ordered meso/porous electrodes [277,278]. Okubo et al [275] have demonstrated an important size-effect occurring in LiMn2O4 particles, confirming that bulk particle sizes are unable to achieve complete lithiation (up to Li2Mn2O4), due to their lower surface area.…”

Methods for promoting electrochemical properties of LiNil/3Col/3Mnl/3O2 for lithium-ion batteries

“…Layered NCM was first prepared by a solid state reaction at 1000°C in air in 2001 [8]. NCM shows a rechargeable capacity of 150 mAh/g in 3.5-4.2 V or 200 mAh/g in 3.5-5.0 V. Research shows that the NCM has the α-NaFeO 2 structure, which is the characteristic of the layered LiCoO 2 and LiNiO 2 structures and shows larger capacity of more than 150 mAh/g in the voltage range of 2.5-4.2 V with excellent cycle ability and no transformation to spinel phase during electrochemical cycling [9][10][11]. The DSC measurements shows the thermal behavior of NCM is milder than that of LiCoO 2 or LiNiO 2 [12].…”