Ultrafine lithium cobalt oxide powder derived from a water-in-oil emulsion process

Evaluation of the intrinsic kinetic activity of nanoparticle ensembles under steady-state conditions

“…Advantages of the RME method include the ability to control the NP size by adjusting the microemulsion water-surfactant molar ratio, the monodispersity of the NPs formed, and the generality of NP synthesis (e.g. metals and alloys [43,44,[88][89][90][91][92][93], metal oxides [94][95][96], and organic polymers [97]). …”

Microemulsion preparation and electrochemical characteristics of LiNi1/3Co1/3Mn1/3O2 powders

“…4 illustrates the charge and discharge characteristics in the first cycle of RE-derived LiNi 1/3 Co 1/3 Mn 1/3 O 2 calcined at 800 • C for 3 h. The electrochemical properties of the sample were measured between 2.5 and 4.5 V at a constant current density of 40 mA g −1 at (a) room temperature and (b) 55 • C. The initial discharge capacities at room temperature and 55 • C were measured to be 187.2 and 195.5 mAh g −1 , respectively. The irreversible capacities for the cell tested at room temperature and 55 • C were also calculated to be 5.6% (11.2 mAh g −1 ) and 4.4% (9 mAh g −1 ), much smaller than the values for LiNi 1/3 Co 1/3 Mn 1/3 O 2 powders prepared via the conventional solid-state process [9,19]. The above phenomenon can be mainly attributed to decreased cation mixing [25].…”

“…Therefore, a microemulsion route was adopted to synthesize LiNi 1/3 Co 1/3 Mn 1/3 O 2 powders in this study. The reverse microemulsion process has been developed by our group to synthesize cathode materials for lithium-ion batteries [19][20][21]. This method has the excellences in controlling particle size and morphology, decreasing nucleation, and lowering reaction temperature for the prepared powders.…”

Cathodes for lithium ion batteries: the benefits of using nanostructured materials

“…Solid state reactions to afford LiCoO 2 may start from many different precursors, such as, Li 2 35 Owing to insufficient mixing, low reactivity of the starting materials and calcinations at 850-900 o C for several hours, LiCoO 2 produced by solid state reactions usually has non-homogeneity, irregular morphology and a broad particle size distribution, which characteristics influence significantly on the electrochemical properties of the product. Taking into account these advantages, alternative methodologies for the solidstate preparations are been proposed in order to synthesize lithium cobalt oxides at micrometer scale, such as solgel, [104][105][106][107][108][109] water-in-oil emulsion process, 110 emulsion drying method, 111 and electrostatic spray deposition. [112][113][114] Although these methods require a much lower calcination time and shorter calcination temperature, the synthesis of particles with size under 100 nm is very hard due to their tendency to agglomerate; therefore, the search for new synthetic methodologies or even the modification of the old ones is still necessary.…”