Sb nanocrystals or Sb-alloy nanocrystals for fast charge/discharge Li- and Na-ion battery anodes
A method for the production of SbM x nanoparticles is described that comprises the steps of reducing an antimony salt and optionally an alloying metal with a hydride in an anhydrous polar solvent, separating the solid product formed from the solution, preferably via centrifugation, and washing the product with water. M is an element selected from the group consisting of Sn, Ni, Cu, In, Al, Ge, Pb, Bi, Fe, Co, Ga, and 0≤x<2.
1. A method for the production of SbM x nanoparticles, wherein
M is an element selected from the group consisting of Sn, Ni, Cu, In, Al, Ge, Pb, Bi, Fe, Co, Ga, and
0≤ x< 2,
the method comprising:
preparing a solution containing an antimony salt and one or more metal salts in an anhydrous polar solvent and at least one solution of hydride in an anhydrous polar solvent, heating the solution containing the one or more metal salts to a reaction temperature, then injecting the solution of hydride into the solution containing the one or more metal salts to generate a reaction mixture and start a reduction reaction, wherein said antimony salt and said one or more metal salts are reduced with said hydride and form a solid product;
cooling said reaction mixture to room temperature immediately after the formation of the solid product; and
separating the solid product formed from the solution reaction mixture, and washing the product with water.
2. The method of claim 1 , wherein the solid product formed from the reaction mixture is separated via centrifugation.
3. The method of claim 1 , wherein M is Sn.
4. The method of claim 1 , wherein M is Sn and x is 1.
5. The method of claim 1 , wherein the reduction reaction is performed after elevating the reaction temperature by heating.
6. The method of claim 5 , wherein the reduction reaction is performed at a temperature of 60±10° C.
7. The method of claim 1 , wherein the hydride is selected from the group consisting of NaBH 4 , lithium hydride, sodium hydride, potassium hydride, magnesium hydride, calcium hydride, tributyltinhydride, diisobutyl aluminum hydride, lithium aluminum hydride, lithium triethylborohydride and mixtures thereof.
8. The method of claim 7 , wherein the hydride is NaBH 4 .
9. The method of claim 1 , wherein the anhydrous polar solvent is selected from the group consisting of 1-methyl-2-pyrrolidone (NW), hexamethylphosphoramide, 1,3-dimethyl-2-imidazolidinone,1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, dimethylsulfoxide, sulfolane, glyme, diglyme, triethylene glycol dimethylether, and mixtures thereof.
10. The method of claim 9 , wherein the anhydrous polar solvent is NMP.
11. The method of claim 1 , wherein the antimony salt is selected from the group consisting of antimony chloride, antimony fluoride, antimony bromide, antimony iodide, antimony oxide or antimony sulfide, antimony sulfate, antimony acetate, potassium antimony tartrate hydrate, triphenylantimony, antimony ethoxide and mixtures thereof.
12. The method of claim 11 , wherein the antimony salt is antimony chloride.
13. The method of claim 1 , wherein the one or more metal salts include at least one salt selected from the group consisting of tin chloride (SnCl 2 ), tin fluoride, tin bromide, tin iodide, tin oxide, tin sulfide, sodium stannate trihydrate, tetrabutyltin, chlorides of Ni, Cu, in, Al, Ge, Pb, Bi, Fe, Co, Ga and mixtures thereof.
14. The method of claim 13 , wherein the one or more metal salts includes a mixture of tin salts.
15. The method of claim 13 , wherein the one or more metal salts includes tin chloride.
16. The method of claim 1 , wherein the reduction reaction is performed in inert gas.
17. The method of claim 16 , wherein the reduction reaction is performed in argon.
18. The method of claim 1 , wherein the reduction reaction is performed in air.
19. The method of claim 1 , wherein the reaction mixture is cooled to room temperature immediately after injecting the solution of hydride.
20. The method of claim 1 , wherein the product is dried in a vacuum oven at room temperature, optionally with a previous additional washing with a low boiling water miscible solvent.
21. The method of claim 20 , wherein the low boiling water miscible solvent is acetone.
22. A method for producing an anode comprising performing the method of claim 1 for producing SbM x nanoparticles, mixing the such obtained SbM x nanoparticles, carbon black, carboxy methyl cellulose (CMC) and demineralized water, coating the aqueous slurry obtained on a current collector and drying.
23. The method according to claim 1 , wherein the anhydrous polar solvent is not dimethyl formamide.