A high-performance composite positive electrode based on graphene and Li (Ni_1/3Co_1/3Mn_1/3)O₂

Abstract

The cathode electrodes in commercial Li-ion cells are usually coated on aluminum foils, while the anode part is coated on copper current collector. However, these metallic foils of the electrodes are relatively heavy counterparts when compared with the total cell weight. To overcome this issue, we comparatively studied LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC); NMC/graphene positive electrodes reinforced with graphene were produced in the form of freestanding electrodes by a facile sol-gel and vacuum filtration method. To confirm our results obtained with the half-cells, graphite@NMC@graphene full-cells were also produced and a specific capacity of 220 mAh g −1 after 250 cycles. Extraordinary electrochemical cycling, high conductivity, and enhanced rate properties are obtained by anchoring the NMC particles between the graphene layers. The results have also indicated that the freestanding graphene-based electrodes could be a useful tool for high-capacity lithium-ion batteries.

Metal Coated Polypropylene Separator with Enhanced Surface Wettability for High Capacity Lithium Metal Batteries

“…The Mn 4+ ions are inactive within the LNMC lattice, as a consequence it results in stabilizing the lattice. In the CV cycle a homologous integral area was observed, suggesting that the Li intercalation and intercalation was highly reversible 10 . Figure 7(a,b) show the charge-discharge curves of LNMC cells without and with Nb-PP separator in a stable voltage range of 2.5 V to 4.5 V. The corresponding specific capacities and efficiencies with cycle number are presented in Fig.…”

“…It exhibits the similar crystal structure as that of LiCoO 2 (rhombohedral, R3m symmetry, with MO 6 octahedral sharing the edges (“M” = Co, Ni, and Mn) and Li ions (Li + ) in the structure occupy the respective octahedral sites.) 9,10 . Ni, Mn, and Co ions exist with valances of +2, +4, and +3, respectively and the Ni 2+ /Ni 4+ and Co 3+ /Co 4+ redox couples are electrochemically active during the insertion/removal of Li + , whilst the Mn 4+ ions remain inactive 11–15 .…”

“…Ni, Mn, and Co ions exist with valances of +2, +4, and +3, respectively and the Ni 2+ /Ni 4+ and Co 3+ /Co 4+ redox couples are electrochemically active during the insertion/removal of Li + , whilst the Mn 4+ ions remain inactive 11–15 . As a consequence, the Mn dissolution and associated Jahn−Teller distortion can be greatly eluded, which in turn results in a more stabilized structure during the electrochemical processes 10,16 . The LiNi 1/3 Mn 1/3 Co 1/3 O 2 cathode offers a practical achievable specific capacity of above 160 mA h g −1 when cycled in 2.5 V to 4.5 V voltage range.…”

A novel high specific capacity lithium-ion capacitor battery with Li+ -doped Ni0.64 Al0.64 Mn0.56 O2 prepared by coprecipitation method as cathode active material

“…The most important thing is that it can effectively and easily improve the specific capacity especially under the condition of high-current discharge without changing the morphology of the original cathode active material of the lithium-ion battery. 24,25 In addition, this metal oxide can carry a greater discharge current so that the structure of cathode material is protected from damage. Therefore, this type of capacitor battery can possess a longer-cycle life.…”

“…In this paper, we synthesized a novel Li + ‐doped Ni 0.64 Al 0.64 Mn 0.56 O 2 cathode material by coprecipitation method, and it just required mixing with commercialized LiNi 1/3 Co 1/3 Mn 1/3 O 2 in altered proportions for cathode materials of capacitor batteries. The most important thing is that it can effectively and easily improve the specific capacity especially under the condition of high‐current discharge without changing the morphology of the original cathode active material of the lithium‐ion battery . In addition, this metal oxide can carry a greater discharge current so that the structure of cathode material is protected from damage.…”