ELECTRODES FOR ENERGY STORAGE DEVICE COMPRISING NOVEL BINDERS
Disclosed herein is an anode comprising a current collector; an anode active layer disposed on the current collector, wherein the anode active layer comprises anode active particles, an anode electrically conducting material and an anode binder; wherein the anode binder comprises a copolymer that comprises a first repeat unit and a second repeat unit; where the first repeat unit is derived from the polymerization of a first monomer that comprises an ether linkage or comprises multiple hydroxyl groups and wherein the second repeat unit is derived from the polymerization of an ethylenically unsaturated monomer that comprises a hydrophilic pendant group.
1 . An anode comprising:
a current collector;
an anode active layer disposed on the current collector, wherein the anode active layer comprises anode active particles, an anode electrically conducting material and an anode binder; wherein the anode binder comprises a copolymer that comprises a first repeat unit and a second repeat unit; where the first repeat unit is derived from the polymerization of a first monomer that comprises an ether linkage or comprises multiple hydroxyl groups and wherein the second repeat unit is derived from the polymerization of an ethylenically unsaturated monomer that comprises a hydrophilic pendant group.
2 . The anode of claim 1 wherein the hydrophilic pendant group is a carboxylic acid group or a carboxylic acid salt group.
3 . The anode of claim 1 , wherein the anode electrically conductive elements form a percolating network.
4 . The anode of claim 1 , where the first monomer further comprises an olefin.
5 . The anode of claim 1 , wherein the anode electrically conductive elements comprise a network of high aspect ratio carbon elements.
6 . The anode of claim 1 , wherein the high aspect ratio carbon elements comprise carbon nanotubes.
7 . The anode of claim 1 , wherein the electrically conductive elements further comprise graphite or carbon black.
8 . The anode of claim 1 , wherein the anode active material comprises a lithium-silicate having the structure Li x Si y O z , where x is 1 to 15, y is 0 to 4 and z is 0 to 9.
9 . The anode of claim 8 , wherein x is 2 to 7, y is 1 or 2 and z is 1 to 5.
10 . The anode of claim 8 , wherein an energy storage device comprising the anode has an initial charge specific capacity of 1500 to 1600 mAh/g.
11 . The anode of claim 8 , having an initial coulombic efficiency of 87 to 89%.
12 . The anode of claim 8 , wherein the lithium-silicate is present in an amount of 40 to 90 wt %, based on a total weight of the anode active layer.
13 . The anode of claim 1 , wherein the anode active layer comprises graphite in an amount of 5 to 60 wt %, based on a total weight of the anode active layer.
14 . The anode of claim 8 , wherein the anode active layer further comprises carbon.
15 . The anode of claim 5 , wherein the network of high aspect ratio carbon elements comprises:
a first set of carbon nanotubes, wherein the first set of carbon nanotubes comprises a plurality of first carbon nanotubes or a plurality of bundles of first carbon nanotubes; and
a second set of carbon nanotubes, wherein:
the second set of carbon nanotubes comprise a plurality of second carbon nanotubes or a plurality of bundles of second carbon nanotubes; and
the second set of carbon nanotubes has one or more properties different from the first set of carbon nanotubes.
16 . The electrode of claim 15 , wherein the first set of carbon nanotubes comprises single wall carbon nanotubes.
17 . The electrode of claim 15 , wherein the second set of carbon nanotubes comprises multiwall carbon nanotubes.
18 . The electrode of claim 15 , wherein:
the first set of carbon nanotubes comprises single wall carbon nanotubes;
the second set of carbon nanotubes comprises multi-wall carbon nanotubes; and
a ratio of an amount by weight of the first set of carbon nanotubes to the second set of carbon nanotubes is from 1:5 to 5:1.
19 . The electrode of claim 5 , wherein the network of high aspect ratio carbon elements comprises a set of multi-wall carbon nanotubes.
20 . An energy storage device comprising the anode of claim 1 .
21 . A method of making the anode of claim 1 comprising
providing a slurry comprising the anode electrically conductive elements, the anode binder and the anode active material in water, alcohol or a combination thereof,
coating the slurry onto a current collector and drying to remove the solvent.
22 . An energy storge device comprising:
a housing;
an electrolyte;
a first current collector;
an anode active material disposed on the first current collector; where the anode active material comprises a network of high aspect ratio carbon elements defining void spaces within the network;
a plurality of anode active material particles disposed in the void spaces within the network; and
an anode polymeric binder, wherein the anode binder comprises a copolymer that comprises a first repeat unit and a second repeat unit; where the first repeat unit is derived from the polymerization of a first monomer that comprises an ether linkage or comprises multiple hydroxyl groups and wherein the second repeat unit is derived from the polymerization of an ethylenically unsaturated monomer that comprises a hydrophilic pendant group; and
a second current collector;
a cathode active material disposed on the second current collector; where the cathode active material comprises a network of high aspect ratio carbon elements defining void spaces within the network;
a plurality of cathode active material particles disposed in the void spaces within the network; where the cathode active material comprises a combination of nickel, manganese and cobalt; and
a cathode polymeric binder, the polymeric binder comprising at least one of a (i) a polyamide (ii) a polyamide copolymer; (iii) a polyacrylic acid copolymer or (iv) a polyacrylate copolymer.
23 . The energy storage device of claim 22 , wherein the anode polymeric binder further comprises carboxymethyl cellulose.
24 . The energy storage device of claim 22 , wherein the cathode polymeric binder further comprises polyvinylpyrollidone.
25 . The energy storage device of claim 22 , wherein the energy storage device displays an initial charge specific capacity of 1500 to 1600 mAh/g.
26 . The energy storage device of claim 22 , wherein the energy storage device displays an initial charge specific capacity of 1400 to 1500 mAh/g with an initial coulombic efficiency of 90 to 94%.
27 . The energy storage device of claim 22 , wherein the energy storage device displays an initial charge specific capacity of 1350 to 1400 mAh/g with an initial coulombic efficiency of 87 to 89%.
28 . The energy storage device of claim 22 , wherein the energy storage device displays a specific energy between 300 and 450 watt-hours/kilogram (Wh/kg).
29 . The energy storage device of claim 22 , wherein the energy storage device displays an energy density between 900 and 1000 watt-hours per liter (Wh/L).