Systems and methods for lithium ion battery cathode material recovery, regeneration, and improvement

Abstract

Lithium ion battery cathode material recycling methods and systems are disclosed. The methods can include plasma-assisted separation, which can simultaneously purify the surface of particles of used or damaged cathode material and isolate larger microparticles from smaller nanoparticles, which produces one group having a desired particle morphology and another group lacking the desired particle morphology. These two groups of particles (when present) are further processed using a micro-molten shell process that generates a molten shell of lithium precursors, with optional chemistry enhancing additives, and employs a thermal/plasma treatment to relithiate the particles, restore morphology to particles lacking the desired morphology, and to upgrade the cathode chemistry when additives are included. The relithiation and morphology restoration are primarily employed on used or damaged materials, whereas the chemistry enhancing/upgrading can be employed on new and used materials.

1 . A method of isolating portions of a mixture of particles composed of used or damaged lithium ion battery cathode material having a single, known cathode chemistry, the method comprising the following steps:
 a) flowing a fluidized gas-solid stream of the mixture of particles and a carrier gas through a plasma region at a predetermined flow velocity and a predetermined solid-to-gas volume ratio;   b) exposing the mixture of particles flowing through the plasma region to a non-equilibrium plasma having a predetermined plasma power density for a predetermined plasma exposure time; and   c) substantially simultaneous to steps a) and b) or immediately following steps a) and b), size-separating the mixture of particles by gas-phase centrifugal separation forces in a vortex motion,   wherein the predetermined flow velocity, the predetermined solid-to-gas volume ratio, the predetermined plasma power density, and the predetermined plasma exposure time are collectively tuned to reduce or eliminate physically adsorbed and/or covalently-bound surface impurities on the mixture of particles,   wherein the predetermined flow velocity, the predetermined solid-to-gas volume ratio, and the exposing of step b) are adapted to provide each particle of the mixture of particles with substantially the same plasma exposure, and   wherein the size-separating of step c) divides the mixture of particles into at least two groups of particles having different size distributions, wherein a first group of the at least two groups has at least 95% of particles with a desired morphology and/or a desired crystallinity, wherein a second group of the at least two groups has at least 95% of particles lacking the desired morphology and/or the desired crystallinity that is present in the first group.   
     
     
         2 . The method of  claim 1 , wherein the predetermined flow velocity is between 2 m/s and 20 m/s. 
     
     
         3 . The method of  claim 1 , wherein the predetermined solid-to-gas volume ratio is between 0.001 and 0.1. 
     
     
         4 . The method of  claim 1 , wherein the predetermined plasma power density is between 0.3 kW and 30 kW per kilogram of the used or damaged lithium ion battery cathode material. 
     
     
         5 . The method of  claim 1 , wherein the predetermined plasma exposure time is between 0.05 s and 10 s. 
     
     
         6 . The method of  claim 1 , wherein the carrier gas is selected from the group consisting of O 2 , air, N 2 , a light alkane, a light alkene, and combinations thereof. 
     
     
         7 . The method of  claim 1 , wherein the non-equilibrium plasma is generated from a dielectric barrier discharge (DBD) electrode, a non-thermal plasma jet device, or a combination thereof. 
     
     
         8 .- 11 . (canceled) 
     
     
         12 . The method of  claim 1 , wherein the size-separating of step c) is tuned to produce a cut-off size and the mixture of particles is divided into the first group of particles and the second group of particles based on the cut-off size, wherein the cut-off size is selected based on the single, known cathode chemistry and known particle sizes corresponding to the desired morphology and/or the desired crystallinity. 
     
     
         13 . The method of  claim 12 , wherein at least 95% of the particles in the first group has an average size larger than the cut-off size and at least 95% of the particles in the second group has an average size smaller than the cut-off size. 
     
     
         14 .- 19 . (canceled) 
     
     
         20 . The method of  claim 1 , wherein the particles in the first group have the desired morphology and the desired crystallinity. 
     
     
         21 . The method of  claim 1 , wherein the particles in the second group lack the desired morphology and the desired crystallinity. 
     
     
         22 . The method of  claim 1 , wherein the size-separating of step c) includes generating a vortex in a cyclone reactor and using a vortex finder. 
     
     
         23 . The method of  claim 1 , the method further comprising mixing the mixture of particles with the carrier gas prior to step a). 
     
     
         24 . The method of  claim 1 , the method further comprising jet-milling the mixture of particles prior to step a). 
     
     
         25 .- 28 . (canceled) 
     
     
         29 . The method of  claim 1 , wherein a temperature of the fluidized gas-solid stream is between 100° C. and 800° C. during steps a) and b). 
     
     
         30 . The method of  claim 1 , wherein absolute pressure during step b) is between 0.005 MPa and 0.1 MPa. 
     
     
         31 . A cyclone-plasma separator comprising:
 a particle and gas mixer having a particle inlet for introducing a mixture of particles into the particle and gas mixer and a gas inlet for introducing a gas into the particle and gas mixer;   a cyclone separator chamber downstream of the particle and gas mixer and positioned to receive the mixture of particles and the gas from the particle and gas mixer, the cyclone separator chamber including a vortex finder in a downstream portion of the cyclone separator chamber;   a plasma reactor comprising a dielectric barrier discharge (DBD) electrode positioned downstream of the particle and gas mixer and upstream of or within the cyclone separator chamber, the DBD electrode adapted to provide a non-equilibrium plasma to the mixture of particles; and   a controller adapted to control one or more of:
 a rate of introducing the mixture of particles into the particle and gas mixer; 
 a rate of introducing the gas into the particle and gas mixer; 
 a plasma exposure power of the non-equilibrium plasma; and 
 a plasma exposure timing of the non-equilibrium plasma. 
   
     
     
         32 .- 72 . (canceled) 
     
     
         73 . A method of adjusting chemistry of particles of lithium ion battery cathode material having a single, known cathode chemistry, wherein the particles are nanoparticles the method comprising the following steps:
 a) at least partially coating the particles with a Li precursor and a cathode-chemistry-adjusting additive, the at least partially coating achieved by either: i) spray drying a suspension comprising a solution of the Li precursor and the cathode-chemistry-adjusting additive having the particles suspended therein; or ii) dry mixing the particles with the Li precursor and the cathode-chemistry-adjusting additive;   b) simultaneous with or subsequent to step a), applying a first elevated temperature to the particles to produce particles at least partially coated with a molten layer of the Li precursor and the cathode-chemistry-adjusting additive; and   c) applying a second elevated temperature and/or a plasma to the particles at least partially coated with a molten layer of the Li precursor and the cathode-chemistry-adjusting additive to produce upgraded lithium ion battery cathode particles.   
     
     
         74 .- 104 . (canceled) 
     
     
         105 . The method of  claim 1 , the method further comprising the following step:
 d) applying a second elevated temperature and/or a plasma to the particles of the second group of the at least two groups to produce relithiated lithium ion battery cathode particles, recovered lithium ion battery cathode particles, or upgraded lithium ion battery cathode particles, the particles are at least partially coated with a molten layer of Li precursor,   wherein the relithiated lithium ion battery cathode particles, the recovered lithium ion battery cathode particles, and the upgraded lithium ion battery cathode particles have the desired morphology and/or a desired crystallinity.   
     
     
         106 . The method of  claim 105 , the method further comprising the following steps:
 e) contacting the particles of of the second group of the at least two groups with the Li precursor, thereby at least partially coating the particles with a non-molten layer of the Li precursor; and   f) applying a first elevated temperature to the particles with the non-molten layer of the Li precursor, thereby producing the particles at least partially coated with the molten layer of the Li precursor.