Lead-lead oxide-carbon nanocomposite for energy storage cells and method of preparation
Lead/lead oxide/carbon (“Pb—O—C”) nanocomposite materials that are useful as electrode active materials for electrodes in lithium and sodium batteries are formed by grinding a mixture of a lead oxide material and a carbon material in a high energy ball mill. A Pb—O—C nanocomposite as described herein comprises Pb and lead oxide nanoparticles homogeneously dispersed in a carbon nanoparticle matrix. In the nanocomposite, other elements (e.g., transition metals, Al, Si, P, Sn, Sb, and Bi) can be alloyed with the Pb nanoparticles, incorporated as a mixed oxide with the lead oxide nanoparticles, or can be present as distinct elemental or oxide nanoparticles within the carbon nanoparticle matrix.
1. A method of preparing a nanocomposite comprising lead (Pb) nanoparticles and lead oxide nanoparticles homogeneously dispersed in a matrix of carbon nanoparticles; the method comprising: grinding a mixture comprising a lead oxide material and a carbon material together in a high-energy ball mill, under an inert atmosphere to form the carbon nanoparticles, the lead oxide nanoparticles, and reduce a portion of the lead oxide to elemental Pb nanoparticles; wherein the ball milling is continued until a homogeneous dispersion of the Pb nanoparticles and lead oxide nanoparticles in the matrix of carbon nanoparticles is formed.
2. The method of claim 1 , wherein the lead oxide material and the carbon material are initially present in the ball mill in a respective weight ratio of about 9:1 to 1:1.
3. The method of claim 1 , wherein the ball milling is continued until the Pb nanoparticles have a mean diameter of 2 to 20 nm as determined by electron microscopy.
4. The method of claim 1 , wherein the ball milling is continued until the lead oxide nanoparticles have a mean diameter of 2 to 20 nm as determined by electron microscopy.
5. The method of claim 1 , wherein the ball milling is continued until the carbon nanoparticles have a mean diameter of 10 to 200 nm as determined by electron microscopy.
6. The method of claim 1 , wherein the lead oxide nanoparticles have a Pb:O atomic ratio of 1:1 to 1:2.
7. The method of claim 1 , wherein the Pb and lead oxide are present in the nanocomposite in a respective molar ratio of 1:0.1 to 0.1:1.
8. The method of claim 1 , wherein lead oxide is present on the surface of at least some of the Pb nanoparticles.
9. The method of claim 1 , wherein lead oxide material comprises at least one material selected from the group consisting of PbO, PbO 2 , and Pb 3 O 4 .
10. The method of claim 1 , wherein carbon material comprises at least one material selected from the group consisting of carbon black, hard carbon, and graphite.
11. The method of claim 1 , further comprising heating the so-formed homogeneous dispersion of the Pb nanoparticles and lead oxide nanoparticles in the matrix of carbon nanoparticles in air at a temperature of 30 to 200° C. so as to oxidize the surface of the Pb nanoparticles to form lead oxide-coated Pb nanoparticles.
12. A method of preparing a nanocomposite comprising lead (Pb) nanoparticles and lead oxide nanoparticles homogeneously dispersed in a matrix of carbon nanoparticles; the method comprising: grinding a mixture comprising a lead oxide material and a carbon material together in a high-energy ball mill, under an inert atmosphere to form the carbon nanoparticles, the lead oxide nanoparticles, and reduce a portion of the lead oxide to elemental Pb nanoparticles; wherein the ball milling is continued until a homogeneous dispersion of the Pb nanoparticles and lead oxide nanoparticles in the matrix of carbon nanoparticles is formed, wherein the mixture of the lead oxide material and the carbon material further comprises at least one additional element selected from the group consisting of a transition metal, Al, Si, P, Sn, Sb, and Bi.
13. The method of claim 12 , wherein the at least one additional element is (a) incorporated within the Pb nanoparticles, (b) incorporated as an oxide within the of lead oxide nanoparticles, (c) dispersed within the matrix of carbon nanoparticles as elemental nanoparticles, (d) dispersed within the matrix of carbon nanoparticles as oxide nanoparticles, or (e) a combination of two or more of (a), (b), (c), and (d).
14. The method of claim 12 , wherein the at least one additional element is selected from the group consisting of Mn, Ni, Fe, Sb, and Sn.
15. The method of claim 12 , wherein the at least one additional element comprises a combination of Sb and Sn, or a combination of Sb and Ni.
16. The method of claim 12 , wherein the at least one additional element is present in the nanocomposite at a concentration of 50% to 100% expressed as a percentage of the Pb in the nanocomposite.
17. The method of claim 12 , wherein lead oxide material comprises at least one material selected from the group consisting of PbO, PbO 2 , and Pb 3 O 4 .
18. The method of claim 12 , wherein carbon material comprises at least one material selected from the group consisting of carbon black, hard carbon, and graphite.
19. The method of claim 12 , wherein the ball milling is continued until the carbon nanoparticles have a mean diameter of 10 to 200 nm, the Pb nanoparticles have a mean diameter of 2 to 20 nm, and the lead oxide nanoparticles have a mean diameter of 2 to 20 nm, as determined by electron microscopy.
20. The method of claim 12 , further comprising heating the so-formed homogeneous dispersion of the Pb nanoparticles and lead oxide nanoparticles in the matrix of carbon nanoparticles in air at a temperature of 30 to 200° C. so as to oxidize the surface of the Pb nanoparticles to form lead oxide-coated Pb nanoparticles.