Composite bilayer coatings for high capacity cathodes and anodes

1. An electrode, comprising:

an electrode core; and

a composite bilayer coating conformally disposed on at least a portion of the electrode core, the composite bilayer coating comprising:

a first metal fluoride layer disposed on at least the portion of the electrode core, the first metal fluoride layer comprising Al x F y W z C a , where x, y, z and a are greater than 0, and

a second metal fluoride layer disposed on the first metal fluoride layer, the second metal fluoride layer comprising Mg x F y , Al x F y , or Li x F y , where x, y are greater than 0.

2. The electrode of claim 1 , wherein the electrode comprises a cathode, and wherein the electrode core comprises one of a lithium-magnesium rich layered-layered, or layered-layered-spinel, a LiCoO 2 , a LiMnNiCoO 2 (NMC, e.g., LiN 1/3 Mn 1/3 Co 1/3 O 2 , LiNi 0.8 Mn 0.1 Ni 0.1 O 2 ) or a Li[Li 0.19 Mn 0.57 Ni 0.16 Co 0.08 ]O 2 .

3. The electrode of claim 1 , wherein the electrode comprises an anode, and wherein the electrode core comprises graphite.

4. The electrode of claim 1 , wherein the composite bilayer coating has a thickness of less than 1 nm.

5. An electrochemical cell, comprising:

a cathode comprising:

a cathode core comprising one of a lithium-magnesium rich layered-layered spinel, a LiCoO 2 , a LiN 1/3 Mn 1/3 Co 1/3 O 2 or a Li[Li 0.19 Mn 0.57 Ni 0.16 Co 0.08 ]O 2 ; and

a cathode composite bilayer coating conformally disposed on at least a portion of the cathode core, the cathode composite bilayer coating comprising:

a cathode first layer disposed on at least the portion of the cathode core, the cathode first layer comprising a first metal fluoride comprising Al x F y W z C a , where x, y, z and a are greater than 0, and

a cathode second layer disposed on the cathode first layer, the cathode second layer comprising a second metal fluoride comprising Mg x F y , Al x F y , or Li x F y , where x, y are greater than 0;

an anode; and

a separator disposed between the cathode and the anode.

6. The electrochemical cell of claim 5 , wherein the anode comprises:

an anode core, and

an anode composite bilayer coating conformally disposed on at least a portion of the anode core, the anode composite bilayer coating comprising:

an anode first layer disposed on at least the portion of the anode core, the anode first layer comprising a third metal fluoride or a third metal sulfide, and

an anode second layer disposed on the anode first layer, the anode second layer comprising a fourth metal fluoride or a fourth metal sulfide.

7. The electrochemical cell of claim 6 , wherein the anode core comprises graphite.

8. The electrode of claim 5 , wherein the cathode composite bilayer coating has a thickness of less than 1 nm.

9. A method, comprising:

providing an electrode comprising an electrode core;

performing A atomic layer deposition cycles of a first precursor material comprising a metal precursor at a first deposition temperature on the electrode;

performing B atomic layer deposition cycles of a second precursor material comprising a first fluoride precursor at a second deposition temperature on the electrode;

performing C atomic layer deposition cycles of a third precursor material comprising a metal precursor at a third deposition temperature on the electrode; and

performing D atomic layer deposition cycles of a fourth precursor material comprising a second fluoride precursor at a fourth deposition temperature on the electrode,

wherein the respective atomic layer deposition cycles form a conformal bilayer coating on at least a portion of the electrode core, the composite bilayer coating comprising:

a first metal fluoride layer disposed on at least the portion of the electrode core, the first metal fluoride layer comprising Al x F y W z C a , where x, y, z and a are greater than 0, and

a second metal fluoride layer disposed on the first metal fluoride layer, the second metal fluoride layer comprising Mg x F y , Al x F y , or Li x F y , where x, y are greater than 0;

applying a secondary treatment, mixing at least a portion of the first layer and a portion of the second layer.

10. The method of claim 9 , wherein the second precursor material is formulated to react with the first precursor material to form the first layer, and wherein the fourth precursor material is formulated to react with the third precursor material to form the second layer.

11. The method of claim 9 , wherein each of the first deposition temperature, the second deposition temperature, the third deposition temperature and the fourth temperature is in a range of 50-200 degrees Celsius.