Method for covering particles, especially a battery electrode material particles, and particles obtained with such method and a battery comprising such particle
A method for covering particles having a diameter of maximally 60 μm by means of atomic layer deposition, whereby said method comprises the step of fluidizing said particles in a fluidized bed reactor using a first reactant gas comprising a first reactant for substantially completely covering said particles with a monolayer of said first reactant.
1. An electrode comprising a plurality of particles having a diameter of maximally 60 μm, wherein the particles are coated with a protective layer having a uniform thickness of about 2 nm or less, wherein the protective layer of the particles is obtained by atomic layer deposition, wherein the particles are lithium containing particles.
2. The electrode of claim 1 , wherein the electrode is a cathode.
3. The electrode of claim 1 , wherein the particles comprise a lithium metal oxide or a lithium metal phosphate.
4. The electrode of claim 1 , wherein the particles comprise one or more of LiMn 2 O 4 , LiCoO 2 , LiNiO 2 , LiFePO 4 , Li 4 Ti 5 O 12 , LiMg x Ni 0.5.-x Mn 1.5 O 4 , and LiFe x Ti y Mn 2-x-y O 4 .
5. The electrode of claim 1 , wherein the particles have a diameter of 10 nm to 60 μm.
6. The electrode of claim 1 , wherein the particles have a diameter of 10 nm to 500 nm.
7. The electrode of claim 1 , wherein the particles have a diameter of 10 nm to 100 nm.
8. The electrode of claim 1 , wherein the particles are coated with a metal oxide layer of about 2 nm or less.
9. The electrode of claim 1 , wherein the particles are coated with an alumina layer of about 2 nm or less.
10. The electrode of claim 1 , wherein the particles are protected from dissolution of transition metal ions in an electrolyte, resulting in a capacity reduction less than 40% when stored at 60° C. in a charged state over a three-month time period.
11. The electrode of claim 1 , wherein the particles comprise one or more of primary particles and hard aggregates of primary particles.
12. The electrode of claim 1 , wherein the particles are obtained using an auto-ignition synthesis method.
13. The electrode of claim 1 , wherein the protective layers on the particles are obtained by
(a) fluidizing the particles in a fluidized bed reactor using a first reactant gas comprising a first reactant for substantially covering said particles with a monolayer of said first reactant;
(b) subsequently fluidizing said particles obtained in step (a) in said fluidized bed reactor using a second reactant gas comprising a second reactant for substantially covering the monolayer on said particles obtained in step (a); and
(c) repeating step (a) and step (b) sequentially to obtain the protective layer having a thickness of about 2 nm or less.
14. A battery comprising the electrode of claim 1 .
15. A powder adapted for use in an electrode, comprising a plurality of particles having a diameter of maximally 60 μm, wherein the particles are coated with a protective layer having a uniform thickness of about 2 nm or less, wherein the protective layer of the particles is obtained by atomic layer deposition, wherein the particles are lithium containing particles.
16. The powder of claim 15 , wherein the particles are lithium containing particles having a diameter of 10 nm to 500 nm and coated with a metal oxide layer of 2 nm or less.
17. The powder of claim 15 , wherein the particles are lithium containing particles having a diameter of 10 nm to 100 nm and coated with an alumina layer of 2 nm or less.