A method for enhancing the efficiency of a liquid fuel is described. The method involves the addition of cobalt hydroxystannate nanoparticles to the liquid fuel to produce an enhanced liquid fuel. The cobalt hydroxystannate nanoparticles may be present at a concentration of 50-200 ppm, and may increase the calorific value of the fuel by a factor of 25-52 times.

A method for enhancing the efficiency of a liquid fuel is described. The method involves the addition of cobalt hydroxystannate nanoparticles to the liquid fuel to produce an enhanced liquid fuel. The cobalt hydroxystannate nanoparticles may be present at a concentration of 50-200 ppm, and may increase the calorific value of the fuel by a factor of 25-52 times.

Mixed-metal oxides and lithiated mixed-metal oxides are disclosed that involve compounds according to, respectively, Ni.sub.xMn.sub.yCo.sub.zMe.sub.O.sub. and Li.sub.1+Ni.sub.xMn.sub.yCo.sub.zMe.sub.O.sub.. In these compounds, Me is selected from B, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Ag, In, and combinations thereof; 0x1; 0y1; 0z<1; x+y+z>0; 00.5; and x+y+>0. For the mixed-metal oxides, 15. For the lithiated mixed-metal oxides, 0.11.0 and 1.93. The mixed-metal oxides and the lithiated mixed-metal oxides include particles having an average density greater than or equal to 90% of an ideal crystalline density.

Mixed-metal oxides and lithiated mixed-metal oxides are disclosed that involve compounds according to, respectively, Ni.sub.xMn.sub.yCo.sub.zMe.sub.O.sub. and Li.sub.1+Ni.sub.xMn.sub.yCo.sub.zMe.sub.O.sub.. In these compounds, Me is selected from B, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Ag, In, and combinations thereof; 0x1; 0y1; 0z<1; x+y+z>0; 00.5; and x+y+>0. For the mixed-metal oxides, 15. For the lithiated mixed-metal oxides, 0.11.0 and 1.93. The mixed-metal oxides and the lithiated mixed-metal oxides include particles having an average density greater than or equal to 90% of an ideal crystalline density.

Embodiments of a method for synthesizing water-soluble metal oxide nanoparticles are disclosed. In one embodiment, the method includes heating a first reaction mixture at a predetermined temperature for a predetermined time duration with continuous stirring to obtain a second reaction mixture that comprises water-soluble metal oxide nanoparticles of a first size. The first reaction mixture includes a reactant and a polyol. The method further includes adding a first predetermined amount of the reactant to the second reaction mixture to obtain a third reaction mixture. The method further includes heating the third reaction mixture at the predetermined temperature for the predetermined time duration with continuous stirring to obtain a fourth reaction mixture comprising water-soluble metal oxide nanoparticles of a second size. The reactant is Fe(acac).sub.3 and the polyol is diethylene glycol (DEG) for synthesizing water-soluble iron oxide nanoparticles.

The present invention provides a positive electrode active material precursor for a secondary battery which includes primary particles of Co.sub.3O.sub.4 or Co0OH, wherein the primary particle contains a doping element in an amount of 3,000 ppm or more, and has an average particle diameter (D.sub.50) of 15 pm or more, and a positive electrode active material for a secondary battery which includes particles of a lithium cobalt-based oxide, wherein the primary particle contains a doping element in an amount of 2,500 ppm or more, and has an average particle diameter (D.sub.50) of 15 m or more.

The present invention provides a positive electrode active material precursor for a secondary battery which includes primary particles of Co.sub.3O.sub.4 or Co0OH, wherein the primary particle contains a doping element in an amount of 3,000 ppm or more, and has an average particle diameter (D.sub.50) of 15 pm or more, and a positive electrode active material for a secondary battery which includes particles of a lithium cobalt-based oxide, wherein the primary particle contains a doping element in an amount of 2,500 ppm or more, and has an average particle diameter (D.sub.50) of 15 m or more.

The present application relates to a precursor of lithium cobalt oxide and preparation method thereof and a composite of lithium cobalt oxide prepared from the precursor of the lithium cobalt oxide. Specifically, the present application relates to the precursor of lithium cobalt oxide having a surface coating structure obtained by performing surface coating on the precursor of the lithium cobalt oxide with a metal oxide, and synthesizing a cathode material of the composite of the lithium cobalt oxide used by an electrochemical device using such precursor. The cathode material of the composite of the lithium cobalt oxide synthesized by such a precursor and the electrochemical device containing such cathode material have better structural stability, better cycle stability and better storage and safety performances during high voltage.

Provided are a cobalt oxide (Co.sub.3O.sub.4) for a lithium secondary battery, having an average particle diameter (D50) of about 14 m to about 19 m and a tap density of about 2.1 g/cc to about 2.9 g/cc, a method of preparing the cobalt oxide, a lithium cobalt oxide for a lithium secondary battery prepared from the cobalt oxide, and a lithium secondary battery including a cathode including the lithium cobalt oxide.

Provided is a process for producing prelithiated particles of an anode active material for a lithium battery. The process comprises: (a) providing a lithiating chamber having at least one inlet and at least one outlet; (b) feeding a plurality of particles of an anode active material, lithium metal particles, and an electrolyte solution (containing a lithium salt dissolved in a liquid solvent) into the lithiating chamber through at least one inlet, concurrently or sequentially, to form a reacting mixture; (c) moving this reacting mixture toward the outlet at a rate sufficient for inserting a desired amount of lithium into the anode active material particles to form a slurry of prelithiated particles dispersed in the electrolyte solution; and (d) discharging the slurry out of the lithiating chamber through the at least one outlet.