Composite electrodes for lithium ion battery and method of making

1 . A method for making a composite electrode for a lithium ion battery comprising the steps of:

preparing a slurry containing particles of a selected inorganic electrode material suspended in a selected solvent;

preheating a porous metallic substrate;

loading said preheated metallic substrate with said slurry;

baking said loaded substrate at a first selected temperature;

curing said baked substrate at a second selected temperature sufficient to form a desired nanocrystalline material within the pores of said substrate;

calendaring the cured composite to reduce internal porosity; and,

annealing said calendared composite at a third temperature greater than said second temperature to produce a self-supporting multiphase electrode.

2 . The method of claim 1 wherein said gel preparing step comprises the following steps:

preparing a precursor solution, comprising:

a solvent;

a source of at least one metallic ion;

at least two ligands, and,

a source of at least one species selected from the group consisting of: oxygen, sulfur, and phosphous;

heating said precursor solution to form nuclei of a first phase;

adding a second solution containing a second phase to form a first slurry comprising nuclei of said first phase capped by said second phase;

adding preformed nanoparticles of at least one additional selected phase to said first slurry; and,

sonicating the resulting mixture to form a homogeneous final slurry suitable for dispensing onto a substrate.

3 . The method of claim 2 wherein said source of at least one metallic ion comprises a soluble salt of a metal selected from the group consisting of: Co, Ni, Mn, Fe, Al, Li, Cu, and Mo.

4 . The method of claim 2 wherein said at least two ligands are selected from the group consisting of: urea, thiourea, nitric acid, sulfuric acid, triethanolamine; acetic acid, and citric acid.

5 . The method of claim 2 wherein the heating of said solution is performed at a temperature in the range of about 80 to 100° C. to form said nuclei.

6 . The method of claim 2 wherein said nuclei are about 10 nm to 5 μm in size.

7 . The method of claim 2 wherein said second solution comprises lithium polysilicate, (Li 2 O) x (SiO 2 ) y , where x/y is 1 to 10.

8 . The method of claim 2 wherein said preformed nanoparticles comprise at least one material selected from the group consisting of: Li 2 WO 4 , Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , Ohara glass®, LiAlGaPO 4 , Li 7−x La 3 (Zr 2−x Nb x )O 12 , LiLaTiO, LiLaZrO, Ti 4 O 7 (Ebonex® ceramic), carbon nanotube; carbon nanowire, carbon nano-particles, semiconductor nanowire, semiconductor nano-particles, metal nanowire, metal nano-particles and ceramic nano-particles.

9 . The method of claim 8 wherein said nanoparticles are in the range of 10 to 100 nm in size and represent about 1 to 30% by weight of the electrode material.

10 . The method of claim 2 wherein said homogeneous slurry has a viscosity from about 100 to 10,000 cP.

11 . The method of claim 1 wherein said substrate comprises metal foam selected from the group consisting of: Ni and Ni alloys, stainless steel, Cu and Cu alloys, Al and Al alloys.

12 . The method of claim 1 wherein said metallic substrate is preheated to a temperature in the range of about 50 to 150° C.

13 . The method of claim 1 wherein said loading step comprises spraying said slurry at a temperature of about 15 to 30° C. onto said 100 to 150° C. preheated substrate at a pressure of about 5 to 50 psi.

14 . The method of claim 1 wherein said baking is performed at about 100 to 200° C. for 1 to 30 minutes.

15 . The method of claim 1 wherein said calendaring is performed at about 20 to 250° C. under a pressure of about 500 to 5000 kg/cm 2 .

16 . The method of claim 1 wherein said annealing is performed at about 300 to 800° C. for 5 to 60 minutes.

17 . The method of claim 2 wherein said first phase comprises a compound selected from the group consisting of:

LiMn 2−x M1 x O 4 where M1 is selected from the group consisting of Al, Sn, Zn, and Fe, and 0≦x≦0.05;

LiCo 1−x M2 x O 2 where M2 is selected from the group consisting of Ni and Al, and 0≦x≦0.5;

LiNi 1−x M3 x O 2 where M3 is selected from the group consisting of Co and Al, and 0≦x≦0.5;

LiMn x Ni y Co z Al t O 2 where x+y+z+t=1, and 0≦(x, y, z, and t)≦1;

LiM4PO 4 , where M4 is selected from the group consisting of Fe, Co, Ni, and Mn;

CuS;

CuM5S where M5 is selected from the group consisting of Fe, Sn, Mo, and Zn;

LiFePO 4 ;

Li 4 Ti 5 O 12 ;

FeS; and,

MoS.

18 . The method of claim 1 wherein said self-supporting electrode comprises 5 to 25 vol. % metal foam and 75 to 95 vol. % of the electrode active materials and other additives.

19 . The method of claim 1 wherein said self-supporting electrode has a final density between 2 and 6 g/cm 3 and no more than 30 vol. % porosity after calendaring and annealing.

20 . The method of claim 1 wherein said composite electrode comprises a cathode material selected from the group consisting of:

CuS;

LiCoO 2 :Al;

LiMn 2−x M1 x O 4 where M1 is selected from the group consisting of Al, Sn, Zn, and Fe, and 0≦x≦0.05;

LiCo 1−x M2 x O 2 where M2 is selected from the group consisting of Ni and Al, and 0≦x≦0.5

LiNi 1−x M3 x O 2 where M3 is selected from the group consisting of Co and Al, and 0≦x≦0.5;

LiMn x Ni y Co 2 Al t O 2 where x+y+z+t=1, and 0≦(x, y, z, and t)≦1;

LiM4PO 4 , where M4 is selected from the group consisting of Fe, Co, Ni, and Mn;

CuM5S where M5 is selected from the group consisting of Fe, Sn, Mo, and Zn;

LiFePO 4 ; Li 4 Ti 5 O 12 ; FeS; and MoS,

and said method includes the additional steps of:

depositing a Li ion conductor on said cathode; and,

depositing a Li anode on said Li ion conductor, thereby forming a Li ion battery.