Ultra-stable silicon anode by three-dimensional nanoarchitecture design
An electrode includes an electrically conductive porous graphene core; a silicon layer disposed on an internal surface of the porous graphene core; and an ion-conductive hybrid silicate layer disposed on the silicon layer.
1 . An electrode comprising:
an electrically conductive porous graphene core;
a silicon layer disposed on an internal surface of the electrically conductive porous graphene core so as to be in contact with said internal surface of the electrically conductive porous graphene core; and
an ion-conductive hybrid silicate layer disposed on the silicon layer.
2 . The electrode according to claim 1 , wherein the electrically conductive porous graphene core comprises N-doped graphene.
3 . The electrode according to claim 1 , wherein the ion-conductive hybrid silicate (HSi) layer is configured to prevent electrolyte infiltration into the silicon layer.
4 . The electrode according to claim 1 , wherein the ion-conductive hybrid silicate (HSi) layer is configured to regulate solid electrolyte interphase (SEI) on an outer surface of the ion-conductive hybrid silicate layer.
5 . The electrode according to claim 1 , wherein the ion-conductive hybrid silicate (HSi) layer comprises silicon oxide Si x O y and organic moeities, wherein x and y are integer numbers.
6 . The electrode according to claim 5 , wherein the organic moeities are selected from the group consisting of: —OCH 3 , —OCH 2 CH 3 and —CH 2 CH 2 SH.
7 . The electrode according to claim 1 , wherein a silicon-oxygen bond forms at an interface between the silicon layer and the ion-conductive hybrid silicate layer (HSi).
8 . The electrode according to claim 1 , wherein the ion-conductive hybrid silicate (HSi) layer has an ionic conductivity greater than 10 −6 S/cm.
9 . The electrode according to claim 1 , wherein the silicon layer has a thickness between 10 nm and 500 nm.
10 . The electrode according to claim 1 , wherein the electrically conductive porous graphene core has a thickness of approximately 0.3 nm to 5 nm.
11 . The electrode according to claim 1 , wherein said electrode has a reversible capacity greater than 1286 mAh/g and a lifespan greater than 1400 cycles.
12 . The electrode according to claim 1 , wherein a mass fraction of the silicon layer to the electrically conductive porous graphene core is higher than 30 wt %.
13 . A method of making an electrode comprising:
growing N-doped graphene on an internal surface of porous nickel (Ni) to obtain a substrate having a three-dimensional bi-continuous N-doped graphene on nickel such that the N-doped graphene covers a pore surface of the porous nickel;
etching the nickel in the substrate to remove the nickel and form a porous N-doped graphene core;
depositing a silicon (Si) layer into the porous N-doped graphene core; and
depositing a layer of inorganic-organic hybrid silicate on the silicon layer to obtain an electrode having the silicon layer sandwiched between the porous N-doped graphene core and the layer of inorganic-organic hybrid silicate.
14 . The method according to claim 13 , wherein growing the N-doped graphene on the internal surface of porous nickel (Ni) comprises growing the N-doped graphene on the internal surface of the porous nickel by chemical vapor deposition (CVD).
15 . The method according to claim 13 , wherein growing the N-doped graphene on the internal surface of porous nickel (Ni) comprises carburizing the porous nickel (Ni) by using a low temperature chemical reaction to form a porous Ni3C, and annealing at a higher temperature to obtain porous graphene on porous nickel.
16 . The method according to claim 13 , wherein depositing the silicon laver into the porous N-doped graphene core comprises depositing the silicon layer using a sputtering method.
17 . The method according to claim 13 , wherein depositing the silicon layer into the porous N-doped graphene core comprises depositing the silicon layer for a period of time greater than 30 minutes to generate a loading mass of silicon greater than 0.085 mg/cm 3 and a thickness of the silicon layer greater than 59 nm.
18 . The method according to claim 13 , wherein depositing the silicon layer into the porous N-doped graphene core comprises coating an internal surface of the N-doped graphene.
19 . The method according to claim 13 , wherein depositing the layer of inorganic-organic hybrid silicate on the silicon layer comprises depositing the layer of inorganic-organic hybrid silicate using a vapor deposition process.
20 . The method according to claim 13 , wherein the layer of inorganic-organic hybrid silicate prevents direct contact of the silicon layer with an electrolyte during operation.
21 . An electrical battery comprising:
a cathode,
an anode spaced apart from the cathode, the anode comprising:
an electrically conductive porous graphene core;
a silicon layer disposed on an internal surface of the electrically conductive porous graphene core so as to be in contact with said internal surface of the electrically conductive porous graphene core, and
an ion-conductive hybrid silicate layer disposed on the silicon layer; and
an electrolyte configured to transfer electric charge between the cathode and the anode.
22 . The electrical battery according to claim 21 , wherein the electrical battery is a lithium-ion battery having lithium in said cathode.
23 . The electrical battery according to claim 21 , wherein the electrically conductive porous graphene core comprises N-doped graphene.
24 . The electrical battery according to claim 21 , wherein the ion-conductive hybrid silicate (HSi) layer is configured to prevent infiltration of the electrolyte into the silicon layer.
25 . The electrical battery according to claim 21 , wherein the ion-conductive hybrid silicate (HSi) layer comprises silicon oxide Si x O y and organic moeities, wherein x and y are integer numbers.
26 . The electrical battery according to claim 21 , wherein the anode is free-standing and re-stackable.