NANOSTRUCTURED MATERIALS FOR BATTERY APPLICATIONS
The present invention relates to nanostructured materials (including nanowires) for use in batteries. Exemplary materials include carbon-comprising, Si-based nanostructures, nanostructured materials disposed on carbon-based substrates, and nanostructures comprising nanoscale scaffolds. The present invention also provides methods of preparing battery electrodes, and batteries, using the nanostructured materials.
1 . A method of making a battery slurry additive comprising:
disposing a plurality of Si-based nanoscale scaffolds on particles of a carbon-based powder substrate comprising carbon black or graphite and forming a porous network,
wherein the particles of the carbon-based powder substrate are between 5 microns and 50 microns,
wherein the plurality of Si-based nanoscale scaffolds have a core-shell structure, and
wherein said porous network comprises mesopores and macropores.
2 . The method as claimed in claim 1 , wherein the Si-based nanoscale scaffolds comprise at least 50% silicon.
3 . The method as claimed in claim 1 , wherein the Si-based nanoscale scaffolds comprise at least 95% silicon.
4 . The method as claimed in claim 1 , wherein the core of the Si-based nanoscale scaffolds comprises crystalline silicon.
5 . The method as claimed in claim 1 , wherein the shell of the Si-based nanoscale scaffolds comprises amorphous silicon or carbon.
6 . The method as claimed in claim 1 , wherein the Si-based nanoscale scaffolds comprise nanowires, nanorods, nanoparticles or nanofilms.
7 . The method as claimed in claim 1 , wherein the Si-based nanoscale scaffolds comprise nanowires with at least one cross-section dimension less than 100 nm.
8 . The method as claimed in claim 1 , wherein the Si-based nanoscale scaffolds comprise nanoparticles with all dimensions less than 50 nm.
9 . The method as claimed in claim 1 , wherein the carbon-based powder substrate comprises at least about 90% carbon by mass.
10 . The method as claimed in claim 1 , wherein the carbon-based powder substrate comprises at least about 95% carbon by mass.
11 . The method as claimed in claim 1 , where the porous network is substantially free of micropores.
12 . The method as claimed in claim 1 , further comprising disposing a conductive polymer coating on the Si-based nanoscale scaffolds.
13 . The method as claimed in claim 1 , further comprising disposing a conductive polymer binder on the Si-based nanoscale scaffolds.
14 . The method as claimed in claim 12 , wherein the conductive polymer comprises one or more of poly(vinylidene fluoride) (PVDF), polypyrrole, polythiophene, polyethylene oxide, polyacrylonitrile, poly(ethylene succinate), polypropylene, poly(β-propiolactone), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), and sulfonated fluoropolymers.
15 . The method as claimed in claim 1 , further comprising forming an artificial solid electrolyte interphase (SEI) layer on the Si-based nanoscale scaffolds.
16 . The method as claimed in claim 1 , further comprising pre-lithiating the Si-based nanoscale scaffolds.
17 . The method as claimed in claim 1 , wherein the core comprises crystalline silicon and the shell comprises amorphous silicon.
18 . The method as claimed in claim 1 , wherein disposing the plurality of Si-based scaffolds on particles of the carbon-based substrate comprises growing the Si-based scaffolds directly on surfaces of the particles of the carbon-based powder substrate.
19 . The method as claimed in claim 1 , wherein disposing the plurality of Si-based scaffolds on particles of the carbon-based substrate comprises growing, from nucleation sites on the particle surfaces, Si-based nanowires rooted to the carbon-based powder substrate.
20 . The method as claimed in claim 1 , wherein disposing the plurality of Si-based scaffolds on particles of the carbon-based substrate comprises growing the Si-based nanoscale scaffolds in situ such that the scaffolds intertwine, interweave, or overlap to form the porous network.
21 . The method as claimed in claim 1 , wherein disposing the plurality of Si-based scaffolds on particles of the carbon-based substrate comprises introducing a silicon-comprising vapor and depositing elemental silicon on the carbon particle surfaces to grow the scaffolds.
22 . The method as claimed in claim 1 , wherein disposing the plurality of Si-based scaffolds on particles of the carbon-based substrate comprises seeding the particle surfaces with a metal-comprising catalyst and growing the Si-based nanoscale scaffolds therefrom.
23 . The method as claimed in claim 1 , wherein disposing the plurality of Si-based scaffolds on particles of the carbon-based substrate comprises attaching the Si-based scaffolds to the surface of the carbon-based substrate.
24 . The method as claimed in claim 23 , wherein the attaching comprises attaching previously formed Si-based scaffolds to the surface of the carbon-based substrate.
25 . The method as claimed in claim 1 , wherein the nanowires intertwine, interweave or overlap to form the porous network.
26 . The method as claimed in claim 1 , further comprising:
disposing a conductive polymer on the plurality of Si-based nanoscale scaffolds.
27 . The method of claim 26 , wherein the conductive polymer comprises a carbon-comprising polymer, and wherein the method further comprises:
heating the conductive polymer in a presence of an inert gas at a temperature between 160° C. and 1000° C. for a duration of about 30 minutes to 5 hours to form a carbon coating.
28 . A battery slurry additive formed by the method as claimed in claim 1 .
29 . A battery anode electrode for lithium-ion batteries, comprising:
(1) a battery slurry additive formed by the method as claimed in claim 1 ; and
(2) a carbon-based material comprising graphite; and
(3) a binder,
wherein the battery anode electrode comprises 1 weight % to 80 weight % of said additive.
30 . The battery anode electrode as claimed in claim 29 , wherein the battery anode electrode comprises 5 weight % to 20 weight % of said Si-based nanoscale scaffolds.
31 . The battery anode electrode as claimed in claim 29 , wherein the battery anode electrode comprises 5 weight % to 30 weight % of said Si-based nanoscale scaffolds.
32 . The battery anode electrode as claimed in claim 29 , wherein the battery anode electrode comprises 5 weight % to 20 weight % of said additive.
33 . A battery anode electrode for lithium-ion batteries, comprising:
(1) a battery slurry additive formed by the method as claimed in claim 1 ; and
(2) a carbon-based material comprising graphite; and
(3) a binder,
wherein the battery anode electrode comprises 5 weight % to 20 weight % of said Si-based nanoscale scaffolds.
34 . A battery comprising an anode electrode as claimed in claim 29 , a cathode electrode, a separator, and an electrolyte.
35 . A battery comprising an anode electrode as claimed in claim 33 , a cathode electrode, a separator, and an electrolyte.