Synthesis of single-crystal nickel-rich cathode materials using flame-assisted spray pyrolysis
A method of synthesis of single crystal nickel-rich cathode materials can include preparing a precursor solution by dissolving lithium nitrate, nickel nitrate, manganese nitrate, and cobalt nitrate in water, aerosolizing the solution of a) in a stream of air using an ultrasonic sprayer, preheating the resulting droplets, premixing the droplets with methane, decomposing the droplets by passing through a co-flow burner, depositing solid particles on a filter, and calcinating the solid particles in a furnace in oxygen to produce a single crystal cathode material.
1 . A method of synthesis of a single crystal nickel-rich cathode material comprising:
a) forming droplets of a precursor solution comprising a nickel salt in a stream of air;
b) preheating the droplets;
c) generating a flame in a burner;
d) decomposing the droplets by passing them through the burner; and
e) calcinating the solid particles in a furnace in the presence of an oxidizing agent at a calcination temperature and for a calcination time to control the size and crystal structure of the single crystal nickel-rich cathode material,
wherein preheating the droplets comprises exposing the droplets to a temperature of 125° C. to 325° C.
2 . The method of claim 1 , wherein the calcination temperature is between 750° C. and 900° C. and the calcination time is between 10 minutes and 2 hours.
3 . The method of claim 1 , wherein the single crystal nickel-rich cathode material comprises single crystal particles having an average size of between 0.5 microns and 5 microns.
4 . The method of claim 1 , wherein the precursor solution comprises urea.
5 . The method of claim 1 , wherein the nickel-rich cathode material comprises lithium-nickel-cobalt-manganese oxide (NCM).
6 . The method of claim 1 , wherein the droplets are passed through a preheating zone at a flow rate of between 5 L/min and 20 L/min.
7 . The method of claim 1 , wherein the solid particles are calcinated for up to 60 minutes at between 825° C. and 875° C.
8 . The method of claim 1 , wherein the precursor solution is prepared by dissolving lithium nitrate, nickel nitrate, manganese nitrate, and cobalt nitrate in water.
9 . The method of claim 1 , further comprising adding excess lithium salt to the precursor solution, wherein the excess lithium salt is between 2% and 20% excess of the mass of the final composition stoichiometry.
10 . The method of claim 1 , wherein the droplets are formed by aerosolizing the precursor solution using an ultrasonic sprayer.
11 . The method of claim 1 , wherein the method is a continuous-flow process.
12 . The method of claim 1 , further comprising depositing the solid particles on a glass-fiber filter after decomposing the droplets.
13 . A method of synthesis of a single crystal nickel-rich cathode material comprising:
a) preparing a precursor solution by dissolving lithium nitrate, nickel nitrate, manganese nitrate, and cobalt nitrate in water;
b) aerosolizing the precursor solution in a stream of air using an ultrasonic sprayer to form droplets;
c) preheating the droplets;
d) generating a premixed methane flame in a burner;
e) decomposing the droplets by passing them through the burner;
f) depositing solid particles on a powder collector; and
g) calcinating the solid particles in a furnace in the presence of an oxidizing agent to produce a single crystal cathode material of a controllable size and crystal structure by controlling the calcination time and calcination temperature,
wherein preheating the droplets comprises exposing the droplets to a temperature of 125° C. to 325° C.
14 . The method of claim 13 , wherein the precursor solution comprises urea.
15 . The method of claim 13 , wherein the nickel-rich cathode material comprises lithium-nickel-cobalt-manganese oxide (NCM).
16 . The method of claim 13 , wherein the nickel nitrate of the precursor solution is nickel nitrate hexahydrate (Ni(NO 3 ) 2 ·6H 2 O).
17 . The method of claim 13 , wherein the manganese nitrate of the precursor solution is manganese nitrate tetrahydrate (Mn(NO 3 ) 2 ·4H 2 O).
18 . The method of claim 13 , wherein the cobalt nitrate of the precursor solution is cobalt nitrate hexahydrate (Co(NO 3 ) 2 ·6H 2 O).
19 . The method of claim 13 , comprising a liquid-feed flame assisted spray pyrolysis (FASP) method.