Anode materials for lithium ion batteries and methods of making and using same
An electrochemically active material includes a silicon alloy material having the formula: Si w M 1 x C y O z , where w, x, y, and z represent atomic % values and w+x+y+z=1; M 1 comprises a transition metal; w>0; x>0; y≥0; and z≥0. The electrochemically active material also includes a metal-based material having the formula: M 2 a O b A c, where a, b, and c represent atomic % values and a+b+c=1; M 2 comprises a metal; A is an anion; a>0; b≥0; and c≥0.
1. An electrochemically negative active material capable of incorporation into an anode, the electrochemically negative active material comprising:
a silicon alloy material comprising an active phase having the formula:
Si w M 1 x C y O z ,
where w, x, y, and z represent atomic % values and w+x+y+z=1;
M 1 comprises Sn, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mg, Al, W, Mo, B, or P; w >0;
x >0; y >0; and z >0; and
a metal-based material having the formula:
M 2 a O b A c,
where a, b, and c represent atomic % values and a+b+c=100%;
M 2 comprises Si, Ti, Mg, Mn, Co, Ni, Cu or Zn;
A is an anion;
a >0; b >0; and c >0, provided that at least one of b and c is not zero; and
wherein the silicon alloy material and the metal-based material contact one another.
2. The electrochemically negative active material according to claim 1 , wherein A is an anion comprising a hydroxide, nitrate, carbonate, sulfate, phosphate, acetate, fluoride, chloride, bromide, iodide, PO 3 , or P 2 O 7 .
3. The electrochemically negative active material according to claim 1 , wherein the electrochemically negative active material comprises the silicon alloy material in an amount of between 50 and 99 wt. %, based on the total weight of the electrochemically active material.
4. The electrochemically negative active material according to claim 3 , wherein the electrochemically negative active material comprises the metal-based material in an amount of between 0.1 and 20 wt. %, based on the total weight of the electrochemically active material.
5. The electrochemically negative active material according to claim 3 , wherein the Scherrer grain size of the active phase of the silicon alloy material is no greater than 50 nanometers.
6. The electrochemically negative active material according to claim 1 , wherein the silicon alloy material is present as particles, and wherein the metal-based material is present as a coating disposed on the particles.
7. A negative electrode composition comprising:
the electrochemically active material according to claim 1 ; and
a binder.
8. A negative electrode composition according to claim 7 , further comprising graphite.
9. A negative electrode comprising:
the negative electrode composition according to claim 7 ; and
a current collector.
10. An electrochemical cell comprising:
the negative electrode of claim 9 ;
a positive electrode comprising a positive electrode composition comprising lithium; and
an electrolyte comprising lithium.
11. An electronic device comprising the electrochemical cell according to claim 10 .
12. A method of making an electrochemical cell, the method comprising:
providing a positive electrode comprising a positive electrode composition comprising lithium;
providing a negative electrode according to claim 9 ;
providing an electrolyte comprising lithium; and
incorporating the positive electrode, negative electrode, and the electrolyte into an electrochemical cell.