BATTERY ANODE
A battery anode including a metallic current collector layer adjacent a first major surface of a graphite layer and a silicon containing anode layer adjacent a second major surface of the graphite layer. One application for such anode is in a lithium-ion battery.
1 . A battery anode comprising a metallic current collector layer adjacent a first major surface of a graphite layer, a silicon containing anode layer adjacent a second major surface of the graphite layer.
2 . The battery anode of claim 1 wherein the metallic current collector bonded to the graphite layer and the silicon containing layer bond to the second major surface of the graphite layer.
3 . The battery anode of claim 2 wherein the metallic current collector comprises copper.
4 . The battery anode of claim 3 wherein the graphite layer comprises graphite particles of natural graphite, intercalated graphite, exfoliated graphite, anode coke, graphitized anode coke, needle coke, graphitized needle coke, natural graphite powder, synthetic graphite powder, milled versions of any of the afore mentioned types of graphite and combinations thereof.
5 . The battery anode of claim 3 wherein a thickness of the graphite layer comprises about 1 to 150 microns.
6 . The battery anode of claim 3 wherein the graphite layer thickness comprises a sufficient thickness to compensate for the volume expansion of the silicon layer during operation of the battery.
7 . The battery anode of claim 1 wherein the silicon layer comprises at least five percent silicon by weight.
8 . The battery anode of claim 1 in a lithium-ion battery.
9 . The battery anode of claim 1 further comprising a second graphite layer adjacent the metallic current collector layer, wherein the graphite layer and the second graphite layer in an opposed relationship to each other.
10 . The battery anode of claim 9 further comprising a second silicon layer adjacent the second graphite layer.
11 . The battery anode of claim 1 having a specific capacity retention percentage of at least eighty percent after 10 or more charge-discharge cycles.
12 . A lithium ion battery comprising an anode constructed from copper, graphite and silicon wherein the copper forms the current collector and the silicon forms the anode functioning layer and the graphite interposed between the silicon and the copper.
13 . The lithium ion battery of claim 12 wherein the graphite in the form of a layer having a thickness of about 1 to 150 microns.
14 . The lithium ion battery of claim 13 wherein the graphite layer comprising particle of synthetic graphite, natural graphite and combinations thereof.
15 . The lithium ion battery of claim 14 wherein the graphite layer bonded to the copper current collector.