High Performance LiMn₂O₄ Cathode Materials Grown with Epitaxial Layered Nanostructure for Li-Ion Batteries

Abstract

Tremendous research works have been done to develop better cathode materials for a large scale battery to be used for electric vehicles (EVs). Spinel LiMn2O4 has been considered as the most promising cathode among the many candidates due to its advantages of high thermal stability, low cost, abundance, and environmental affinity. However, it still suffers from the surface dissolution of manganese in the electrolyte at elevated temperature, especially above 60 °C, which leads to a severe capacity fading. To overcome this barrier, we here report an imaginative material design; a novel heterostructure LiMn2O4 with epitaxially grown layered (R3̅m) surface phase. No defect was observed at the interface between the host spinel and layered surface phase, which provides an efficient path for the ionic and electronic mobility. In addition, the layered surface phase protects the host spinel from being directly exposed to the highly active electrolyte at 60 °C. The unique characteristics of the heterostructure LiMn2O4 phase exhibited a discharge capacity of 123 mAh g(-1) and retained 85% of its initial capacity at the elevated temperature (60 °C) after 100 cycles.

High‐Performance Heterostructured Cathodes for Lithium‐Ion Batteries with a Ni‐Rich Layered Oxide Core and a Li‐Rich Layered Oxide Shell

“…Recently, many studies have reported that the rate performance of active materials depends highly on their surface stability because the surface instability continuously leads to the formation of side reactions with the electrolyte and structural reorganizations, in turn resulting in a severe degradation of lithium‐ion and electronic mobilities 6, 13, 30. Therefore, although it is well known that the surface Li 1.2 Ni 0.2 Mn 0.6 O 2 phase has a lower lithium‐ion and electronic conductivity than the bare LiNi 0.7 Co 0.15 Mn 0.15 O 2 phase, the coated sample shows better rate capability.…”

Temperature-dependent oxygen behavior of LixNi0.5Mn1.5O4 cathode material for lithium battery

“…[7][8][9] The 4 V LiMn 2 O 4 -modified composition LiNi x Mn 2-x O 4 materials have raised interest due to the high operating voltage of ∼4.7 eV for a dense energy cathode material. [10][11][12][13][14] Among different Ni/Mn contents in LiNi x Mn 2-x O 4 , various studies such as synthetic method, [15][16][17][18] thermal stability, [19][20][21][22] effects of ordered and disordered local structures, 23 cation ordering, 24 particle size, 25,26 and composition change [27][28][29] have been reported on LiNi 0.5 Mn 1.5 O 4 .…”

One-dimensional nanostructured design of Li1+x(Mn1/3Ni1/3Fe1/3)O2 as a dual cathode for lithium-ion and sodium-ion batteries

“…They could also be possible candidates for applications such as EVs and electrical grids. [11][12][13][14][15] LiNiO 2 and LiMnO 2 are considered to be promising cathode candidates for LIBs due to their inexpensiveness and higher possible capacities of 160 mA h g À1 and 120-190 mA h g À1 , respectively, but they suffer from various issues associated with the cost of their preparation techniques, the problems to do with the preparation of materials without cation mixing, structural degradation during the cycling process, and thermal instability. 8,9 LiCoO 2 is a viable cathode material with a theoretical capacity of 272 mA h g À1 and a limited reversible capacity of 140 mA h g À1 corresponding to 0.5 Li per LiCoO 2 in the voltage range of 3-4.2 V. Nevertheless, LiCoO 2 suffers from the high cost of Co, along with its toxic nature and lack of environmental friendliness.…”