MULTIMODAL SILICON-CARBON COMPOSITE MATERIAL, AN ANODE COMPRISING THE SAME AND A METHOD TO MANUFACTURE OF THE SAID COMPOSITE MATERIAL

1 . A silicon-carbon composite mixture comprising:

a) a first silicon-carbon composite material comprising:

i. a porous carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 6 μm to 20 μm;

b) a second silicon-carbon composite material comprising:

i. a second carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 1 μm to 6 μm; and

c) 10% to 90% by mass of the first silicon-carbon composite material and 10% to 90% by mass of the second silicon-carbon composite material.

2 . The silicon-carbon composite mixture of claim 1 , wherein the mixture further comprises one or more additional silicon-carbon composite wherein each of the one or more additional silicon-carbon composites comprises a unique Dv50.

3 . The silicon-carbon composite mixture of claim 1 or 2 , wherein the silicon-carbon composite mixture has a surface area of less than 30 m 2 /g.

4 . The silicon-carbon composite mixture of claim 1, 2 or 3 , wherein E is greater than 0.01, wherein E is defined as 1−(density for composite mixture)/(mass averaged density for individual fractions), wherein density is the electrode density as measured in an electrode composed of 70 wt % composite, 20 wt % graphite, and 2 wt % Super C65, and 8% PAA.

5 . The silicon-carbon composite mixture of claim 4 , wherein for the determination of E, measurement of electrode properties of the silicon-carbon composite mixture and the individual fractions comprising each mode are measured under otherwise identical conditions.

6 . A silicon-carbon composite mixture comprising:

a) a first silicon-carbon composite material comprising:

i. a porous carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 6 μm to 20 μm;

b) a second silicon-carbon composite material comprising:

i. a second carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 1 μm to 6 μm;

c) 10% to 90% by mass of the first silicon-carbon composite material and 10% to 90% by mass of the second silicon-carbon composite material;

d) a surface area of less than 30 m 2 /g;

e) E greater than 0.01, wherein E is defined as 1−(tap density for composite mixture)/(mass averaged tap density for individual fractions); and

f) for the determination of E, measurement of tap density of the silicon-carbon composite mixture and the individual fractions comprising each mode are measured under otherwise identical conditions.

7 . A silicon-carbon composite mixture comprising:

a) a first silicon-carbon composite material comprising:

i. a porous carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 6 μm to 20 μm;

b) a second silicon-carbon composite material comprising:

i. a second carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 1 μm to 6 μm;

c) 10% to 90% by mass of the first silicon-carbon composite material and 10% to 90% by mass of the second silicon-carbon composite material;

d) a surface area of less than 30 m 2 /g; and

e) E greater than 0.01, wherein E is defined as 1−(conductivity for composite material)/(mass averaged conductivity for individual fractions).

8 . The silicon-carbon composite mixture of any one of claims 1-7 , wherein E is greater than 0.05.

9 . The silicon-carbon composite mixture of any one of claims 1-7 , wherein E is greater than 0.1.

10 . A method to manufacture a silicon-carbon composite mixture comprising the steps:

a) providing a porous carbon scaffold;

b) comminution the porous carbon scaffold to produce at least two particulate fractions, comprising:

i. a first porous carbon composite material comprising a plurality of particles with Dv50=6 μm to 20 μm;

ii. a second porous carbon composite material comprising a particle size distribution with Dv50=1 μm to 6 μm; and

c) impregnation of silicon into the pores of the at least two particulate fractions of porous carbon composite materials by chemical vapor infiltration to produce a first silicon-carbon composite and a second silicon-carbon composite; and

d) blending of the first silicon-carbon composite and the second silicon-carbon composite material.

11 . The silicon-carbon composite mixture of any one of claims 1-10 , wherein the mixture comprises the first fraction of the first silicon-carbon composite with a proportion of 60% to 90% by weight and the second silicon-carbon composite with a proportion of 10% to 40% by weight.

12 . The silicon-carbon composite mixture of any one of claim 1-11 , wherein the mixture comprises the first fraction of the first silicon-carbon composite with a proportion of 70% to 90% by weight and the second silicon-carbon composite with a proportion of 10% to 30% by weight.

13 . A method to manufacture a silicon-carbon composite mixture comprising the steps:

a) providing a porous carbon scaffold;

b) comminution the porous carbon scaffold to produce at least two particulate fractions, comprising:

i. a first porous carbon composite material comprising a plurality of particles with Dv50=6 μm to 20 μm;

ii. a second porous carbon composite material comprising a particle size distribution with Dv50=1 μm to 6 μm; and

c) impregnation of silicon into the pores of the at least two particulate fractions of porous carbon composite materials by chemical vapor infiltration;

d) applying a coating onto the surface of the at least two particulate fractions of the porous silicon-carbon composite by chemical vapor deposition; and

e) blending of the first particulate silicon-carbon composite material and the second particulate silicon-carbon composite material.

14 . An anode electrode, comprising a silicon-carbon composite mixture comprising:

a) a first silicon-carbon composite material comprising:

i. a porous carbon scaffold comprising micropores and mesopores; and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 6 μm to 20 μm;

b) a second silicon-carbon composite material comprising:

i. a second carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 1 μm to 6 μm; and

c) 10% to 90% by mass of the first silicon-carbon composite material; and 10% to 90% by mass of the second silicon-carbon composite material.

15 . The anode electrode of claim 14 , wherein the surface area of the silicon-carbon composite mixture is less than 30 m 2 /g.

16 . The anode electrode of claim 14 or 15 , wherein the anode electrode has a density comprising E greater than 0.01, wherein E is defined as 1−(density for composite mixture)/(mass averaged density for individual fractions), wherein density is the electrode density as measured in an electrode composed of 70 wt % composite, 20 wt % graphite, and 2 wt % Super C65, and 8% PAA.

17 . The anode electrode of claim 16 , wherein for the determination of E, measurement of electrode properties of the silicon-carbon composite mixture and the individual fractions comprising each mode are measured under otherwise identical conditions.

18 . The anode electrode of claim 14 or 15 , wherein the anode electrode has a density comprising E greater than 0.01, wherein E is defined as 1−(tap density for composite mixture)/(mass averaged tap density for individual fractions), wherein density is the electrode density as measured in an electrode composed of 70 wt % composite, 20 wt % graphite, and 2 wt % Super C65, and 8% PAA.

19 . The anode electrode of claim 18 , wherein for the determination of E, measurement of electrode properties of the silicon-carbon composite mixture and the individual fractions comprising each mode are measured under otherwise identical conditions.

20 . The anode electrode of any one of claims 16-19 , wherein E is greater than 0.05.

21 . The anode electrode of any one of claims 16-19 , wherein E is greater than 0.1.

22 . The anode electrode according to any one of claims 14-21 , wherein the silicon-carbon composite mixture comprises at least one further carbon and/or at least one binder.

23 . The anode electrode according to claim 22 , wherein the at least one further carbon and/or the at least one binder is dissolved in an aqueous medium.

24 . The anode electrode according to any one of claims 14-23 , wherein the silicon-carbon composite mixture is composed such that the silicon-carbon composite mixture has an electron density ranging from 1.05 g/cm 3 to 1.5 g/cm 3 , or from 1.1 g/cm 3 and 1.3 g/cm 3 .

25 . The anode electrode according to any one of claims 14-24 , wherein the silicon-carbon composite mixture has an electrical conductivity ranging from 0.3 S/cm to 2 S/cm, or from 0.5 S/cm and 1.2 S/cm.

26 . The anode electrode according to any one of claims 14-25 , wherein the carbon is a hard carbon material, a graphitic carbon, or a metal oxide.

27 . The anode electrode according to any one of claims 14-26 , wherein the at least one binder is configured to bind the porous carbon and the silicon content of the first silicon-carbon composite, the porous carbon and the silicon-carbon portion of the second silicon-carbon composite and/or the first silicon-carbon composite and the second silicon-carbon composite.

28 . The anode electrode according to any one of claims 14-27 , wherein the silicon-carbon composite mixture comprises at least one additional binder.

29 . The anode electrode according to any one of claim 22, 23, 27, or 28 , wherein the at least one binder or additional binder is a styrene-butadiene gum/carboxymethylcellulose (CMC/SBR) mixture, a polyacrylic acid (PAA) and/or a lithium polyacrylic (LiPAA) or a sodium polyacrylic (NaPAA).

30 . A method of manufacturing an anode electrode according to any one of claims 14-29 , comprising the steps:

a) mixing the silicon-carbon composite mixture with at least one carbon, to create a mixture;

b) combining the mixture and a binder solution in a twin screw extruder, thereby forming an electrode paste;

c) applying the electrode paste to a conductor thereby producing at least one electrode; and

d) drying the at least one electrode at a temperature of 100° C. to 140° C.

31 . An electrochemical storage device, especially formed as a lithium-ion-battery, comprising:

a) at least one anode electrode, according to any one of claims 14-29 ;

b) at least one electrode, formed as a cathode, comprising a transition metal oxide;

c) a separator disposed between the cathode and the anode; and

d) an electrolyte comprising lithium ions.

32 . Usage of a silicon-carbon composite mixture in an anode electrode, the silicon-carbon composite material comprising:

a) a first silicon-carbon composite material comprising:

i. a porous carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 6 μm to 20 μm;

b) a second silicon-carbon composite material comprising:

i. a second carbon scaffold comprising micropores and mesopores and a total pore volume no less than 0.5 cm 3 /g;

ii. a silicon content from 30% to 70%;

iii. a plurality of particles comprising a Dv50 of 1 μm to 6 μm; and

c) 10% to 90% by mass of the first silicon-carbon composite material and 10% to 90% by mass of the second silicon-carbon composite material.

33 . The use according to claim 32 , wherein the surface area of the silicon-carbon composite mixture is less than 30 m 2 /g.

34 . The use according to claim 32 or 33 , wherein the anode electrode has a density comprising E greater than 0.01, wherein E is defined as 1−(density for composite mixture)/(mass averaged density for individual fractions), wherein density is the electrode density as measured in an electrode composed of 70 wt % composite, 20 wt % graphite, and 2 wt % Super C65, and 8% PAA.

35 . The use according to claim 34 , wherein for the determination of E for the silicon-carbon composite mixture and the individual fractions comprising each mode are measured under otherwise identical conditions.

36 . The use according to claim 34 or 35 , wherein E is greater than 0.05.

37 . The use according to claim 34 or 35 , wherein E is greater than 0.1.

38 . Usage of an anode electrode according to anyone of the claims 14-29 in an electrochemical storage device.