Electrochemically active materials and methods of preparing the same
Methods of preparing an electrochemically active material can include providing electrochemically active particles, coating the particles with a binder, and exposing the particles to a source of metal. The methods can also include forming metal salt on the surface of the particles from the source of metal and heating the metal salt to form metal oxide coated particles.
1. An electrochemically active material for use in creating an anode, comprising:
electrochemically active particles;
a binder; and
a metal oxide formed on the surface of the electrochemically active particles, wherein the metal oxide comprises a conformal cerium oxide layer over the electrochemically active particles, wherein the metal oxide is without cerium oxide aggregates;
wherein the binder comprises a surfactant comprising one or more of sodium dodecylsulfonate, sodium dodecylbenzenesulfonate, sodium dialkylsulfosuccinate, alkylbenzene sulfonates, alcohol ether sulfates, secondary alkane sulfonates, and cetyltrimethylammonium bromide (CTAB); and
wherein the electrochemically active particles comprise silicon particles at greater than about 50% to about 99% by weight which are substantially pure silicon.
2. The electrochemically active material of claim 1 , wherein the silicon particles have a median particle size (D50) greater than about 1 μm to about 50 μm.
3. The electrochemically active material of claim 1 , wherein the binder comprises a polymer having a molecular weight in the range of about 20,000 g/mol to about 40,000 g/mol.
4. The electrochemically active material of claim 3 , wherein the polymer has an ethylene backbone.
5. The electrochemically active material of claim 1 , further comprising adding metal oxide particles with the metal oxide coated silicon particles.
6. The electrochemically active material of claim 5 , wherein the metal oxide particles have a median particle size (D50) in the range of about 20 nm to about 2 μm.
7. The electrochemically active material of claim 5 , wherein the metal oxide particles comprises at least one of TiO 2 , Al 2 O 3 , MoO 2 , CuO, ZnO, SnO 2 , Nb 2 O 5 , RuO 2 , IrO 2 , TiNb 2 O 7 , Zn x Fe y O z , wherein 1<x,y,z<4, and M-Li x O, wherein M is a transition metal and 0.1≤x≤2.
8. The electrochemically active material of claim 1 , wherein the metal oxide comprises CeO x , wherein 1≤x≤2.
9. The electrochemically active material of claim 8 , wherein the source of metal for the metal oxide comprises a cerium-doped material.
10. The electrochemically active material of claim 9 , wherein the cerium-doped material comprises at least one of cerium (IV) oxide-yttria doped material, cerium-doped copper, cerium doped cobalt oxide, and cerium-doped indium oxide.