Anode compositions for rechargeable batteries and methods of making same

1. An anode composition comprising:

an electrochemically active material comprising silicon; and

a cement;

wherein the electrochemically active material and the cement form secondary composite particles, the secondary composite particles comprising the electrochemically active material and the cement.

2. The anode composition of claim 1 , wherein the cement comprises an acid-base cement.

3. The anode composition according to claim 1 , wherein the electrochemically active material comprises an insulating phase.

4. The anode composition according to claim 1 , wherein the electrochemically active material comprises a conducting phase.

5. The anode composition according to claim 1 , wherein the silicon is present in a form selected from the following: elemental silicon, a metal silicide, a silicon carbide, a silicon nitride, a silicon boride, a silicon oxide, or combinations thereof.

6. The anode composition according to claim 1 , wherein the electrochemically active material comprises elemental silicon.

7. The anode composition according to claim 1 , wherein the electrochemically active material has a formula (I):

Si a Sn b M c C d Q e O f E g   (I)

where a, b, c, d, e, f and g represent atomic percent values and (i) a>0; (ii) b≥0, (iii) c≥0, (iv) d≥0; (v) e≥0; (vi) f≥0; (vii) g≥0; (viii) M is one or more metals selected from the group consisting of manganese, molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, or combinations thereof; (ix) Q is one or more elements selected from the group consisting of sodium, lithium, potassium, magnesium, calcium, titanium, boron, aluminum, a rare earth metal, or combinations thereof; and (x) E is one or more elements selected from the group consisting of boron and nitrogen.

8. The anode composition according to claim 1 , wherein the electrochemically active material has a formula (II):

Si x Sn q M y C z   (II)

where q, x, y, and z represent atomic percent values and (i) (q+x)>(2y+z); (ii) x>0; (iii) q≥0, (iv) z≥0; (v) y≥0; and (vi) M is one or more metals selected from manganese,

molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, or combinations thereof.

9. The anode composition according to claim 8 , wherein the Si, Sn, M, and C elements are arranged in the form of a multi-phase microstructure comprising: (i) an amorphous phase comprising silicon; (ii) a nanocrystalline phase comprising a metal silicide; (iii) a phase comprising silicon carbide when z>0; and (iv) an amorphous phase comprising Sn when q>0.

10. The anode composition according to claim 2 , wherein the composite particles have an average size of between 5-50 μm.

11. The anode composition according to claim 2 , wherein the composite particles have an average surface area of between 0.1-10 m 2 /g.

12. The anode composition according to claim 2 , wherein the amount of cement in the particles is between 5-40 wt. %, based upon the total weight of the composite particles.

13. A rechargeable battery comprising:

a cathode;

an electrolyte; and

an anode comprising the anode composition according to claim 1 .

14. An electronic device comprising a rechargeable battery according to claim 13 .

15. A method of making an anode composition, the method comprising:

combining (i) precursor materials of an electrochemically active material comprising silicon; and (ii) a base source to form a mixture;

milling the mixture to form a milled mixture;

combining the milled mixture and an acid source to form a second mixture; and

subjecting the second mixture to a heat treatment to form an acid-base cement monolith.

16. The method of making an anode composition according to claim 15 , wherein the acid source comprises an aqueous solution of a polymeric acid.

17. The method of making an anode composition according to claim 16 , wherein the polymeric acid comprises poly(acrylic acid).

18. A method of making a rechargeable battery, the method comprising:

providing a cathode;

providing an anode, wherein the anode comprises the anode composition according to claim 1 ; and

incorporating the cathode and anode into a battery comprising an electrolyte.

19. A negative electrode composition comprising:

the anode composition according to claim 1 ;

graphite; and

a binder.

20. The rechargeable battery of claim 13 , wherein the rechargeable battery comprises a lithium-ion battery.