LiMn2O4 microspheres: Synthesis, characterization and use as a cathode in lithium ion batteries

Abstract

Solid and hollow microspheres of LiMn 2 O 4 have been synthesized by lithiating MnCO 3 solid microspheres and MnO 2 hollow microspheres, respectively. The LiMn 2 O 4 solid microspheres and hollow microspheres had a similar size of about 1.5 μm, and the shell thickness of the hollow microspheres was only 100 nm. When used as a cathode material in lithium ion batteries, the hollow microspheres exhibited better rate capability than the solid microspheres. However, the tap density of the LiMn 2 O 4 solid microspheres (1.0 g/cm 3 ) was about four times that of the hollow microspheres (0.27 g/cm 3 ). The results show that controlling the particle size of LiMn 2 O 4 is very important in terms of its practical application as a cathode material, and LiMn 2 O 4 with moderate particle size may afford acceptable values of both rate capability and tap density.

High Tap Density Co and Ni Containing P2‐Na0.66MnO2 Buckyballs: A Promising High Voltage Cathode for Stable Sodium‐Ion Batteries

“…The tap densities of samples recorded in the present work are remarkably highest values (more than 2 to 3 times higher) yet reported for sodium‐based layered cathode methods . As previously discussed by many researchers, the tap density of the cathode materials is intimately related to the energy density of energy storage devices . It is well known that a high tap density of solid microspheres results an enhanced volumetric specific capacity.…”

“…Therefore, NMC‐200 buckyballs would not be the best material in terms of the discharge capacity and rate performance. On the other hand, Na‐NMC‐180 with an well‐organized particle size and a homogeneous distribution (between 4 and 5 µm) presents an improved tap density and an enhanced volumetric energy density . In addition, a smooth and clear surface of Na‐NMC‐180 buckyballs is expected to ease the electrolyte penetration into the bulk.…”

“…Although downsizing the final product is considered to be an effective way to promote the storage behaviors of most electrode materials, it significantly affects the tap density thereby decreasing the volumetric energy density of the half‐cell . Instead, fabricating microsized spherical particles with an uniform size distribution can certainly generate the close packed arrays, which remarkably improve the tap density than that of the irregular shaped particles . Moreover, cathode materials with the uniform spherical particles are also promising for making better electrodes for their excellent fluidity and dispersity.…”

“…Consequently, the development of spherically P2‐type layered cathode materials with a uniform particle size distribution is highly obligatory, imposing a great impact on the rate capability of SIBs. Although several spherical cathode materials had been reported to exhibit high rate performance for LIB, the preparation and application of such morphology for SIB is not yet explored well …”

Recent Developments on and Prospects for Electrode Materials with Hierarchical Structures for Lithium‐Ion Batteries

“…LiMn 2 O 4 features a cubic symmetry with Fd3 m space group. [61][62][63][64][65][66] Cho and co-workers fabricated 5 wt% LiNi 0.5 Mn 0.5 O 2 -coated LiMn 2 O 4 via a spray-drying process, and the heterostructured LiMn 2 O 4 delivered a discharge capacity of 123 mAh g −1 with capacity retention of 85% at 60 °C after 100 cycles. The edge-sharing MnO 6 octahedra in LiMn 2 O 4 form a continuous 3D cubic array, leading to a robust spinel framework.…”