Unit Cells Accommodating Expansion of Electrode Active Material
Unit cells for use in electrical current conductance, the electrode structure comprising an electrode separated from a counter electrode by a separator, the unit cell being configured to accommodate expansion of electrode active material during a second use of the device e.g., at least in part by using spacer structures.
1 . (canceled)
2 . A device for electrical current conductance, the device comprising: a unit cell having components comprising an electrode separated by a separator from a counter-electrode, each of the components being stacked along a first axis of the unit cell, the electrode comprising an electrode active material facing the separator, a side of the separator facing the electrode active material being coupled with spacer structures to generate a portion disposed between the separator and the electrode active material, the portion being disposed away from terminals of the separator along a second axis normal to the first axis, the portion being devoid of the separator and devoid of the electrode active material during at least a first use of the device, the device being configured to accommodate expansion of the active material into the portion during a second use of the device.
3 . The device of claim 2 , wherein at least two of the spacer structures are each disposed at a periphery of the unit cell relative to the first axis.
4 . The device of claim 2 , wherein materials of spacers are of the same type, the spacers being of the spacer structures.
5 . The device of claim 2 , wherein the spacer structures comprise materials that are relatively inert and/or unreactive, (a) in operation of the device and (b) in storage of the device.
6 . The device of claim 2 , wherein the portion is disposed between two immediately adjacent spacer structures along the second axis.
7 . The device of claim 2 , wherein the spacer structures comprise a material different from that of the separator.
8 . The device of claim 2 , wherein the spacer structures are generated separately from the separator.
9 . The device of claim 2 , wherein the spacer structure comprises a non-porous material.
10 . The device of claim 2 , wherein the spacer structures occupy a total volume of less than 35% of the electrode.
11 . The device of claim 2 , wherein the spacer structures are configured to provide mechanical strength to withstand pressures exerted during use of the device to substantially maintain a predetermined size and shape.
12 . The device of claim 2 , wherein the spacer structures comprise a material that substantially maintains a predetermined size and shape during use of the device including the first use and the second use.
13 . The device of claim 2 , wherein the second use comprises charging the unit cell or forming the unit cell to form a solid electrolyte interface (SEI) on the electrode active material
14 . The device of claim 2 , wherein the spacer structures comprise a polymer.
15 . The device of claim 2 , wherein the spacer structures are disposed at opposing sides of at least one of the components.
16 . The device of claim 2 , wherein the portion is configured to accommodate an irregular and/or jagged surface of the electrode active material facing the separator.
17 . The device of claim 2 , wherein the separator comprises a porous material, the porous material (i) comprising a particulate material and a binder, and (ii) having a porosity of at least 20% by volume.
18 . The device of claim 17 , wherein the porous material comprises a microporous material.
19 . The device of claim 2 , wherein the separator is configured to allow a liquid electrolyte to propagate therethrough.
20 . The device of claim 2 , wherein (a) the separator, (b) the spacer structures, or (c) the separator and the spacer structures, comprises a polyolefin.
21 . The device of claim 2 , wherein the separator comprises an inorganic material comprising an aluminate and/or a hydroxide.
22 . The device of claim 2 , wherein the device comprises unit cells similar to and including the unit cell, the unit cells stacked along the first axis.
23 . The device of claim 22 , wherein (i) each of the electrode and each of the counter-electrode, has a length of from 5 mm to 500 mm, a width of from 0.01 mm to 2.5 mm, and a height of from 0.05 mm to 10 mm; and wherein the unit cells includes at least 2, 4, 10, 25, 50, or 100 unit cells.
24 . The device of claim 22 , wherein each of the electrode and each of the counter-electrode, has (a) a length to a width of at least 5:1 or higher, (b) a length to a height of at least 5:1 or higher, and/or (c) the height to the width between 0.4:1 and 1000:1; and
wherein the unit cells includes at least 2, 4, 10, 25, 50, or 100 unit cells.
25 . The device of claim 2 , wherein each of the electrodes comprises electrode active material comprising carbon, silicon, or a composite thereof.
26 . The device of claim 2 , wherein the electrode comprises electrode active material comprising soft carbon, hard carbon, silicon, an alloy of silicon, or a composite material, the electrodes being anodes.
27 . The device of claim 2 , wherein the device comprises a secondary battery including the unit cell.
28 . A method for fabricating the device of claim 2 , the method comprising performing one or more operations to fabricate the device.