Method to create a lithium manganese nickel oxide cathode using ultra-pure electrolytic manganese dioxide for improved electrochemical cell performance
A method of forming an LMNO cathode with electrolytic manganese dioxide includes dissolving metallic manganese in acid to create a dissolved manganese solution, disposing the solution within an electrolytic cell including an electrolytic cell anode and an electrolytic cell cathode, and applying a current between the cell anode and the cell cathode to the solution. Applying the current forms an MnO 2 deposit upon the cell anode. The method further includes harvesting the deposit, creating a manganese precursor by neutralizing the deposit and grinding the deposit to form an MnO 2 powder, and mixing the manganese precursor with a nickel precursor and a lithium precursor to create a mixture. The method further includes calcining the mixture to create an LMNO powder and coating a current collector with the LMNO powder to thereby form the LMNO cathode. The method may include testing the cathode electrode in an electrochemical pouch format cell.
1 . A method of forming a battery including a lithium manganese nickel oxide cathode, the method comprising:
providing an anode for the battery, a separator for the battery, and an electrolyte solution for the battery;
forming the lithium manganese nickel oxide cathode, wherein the forming includes:
dissolving metallic manganese in acid to create a dissolved manganese solution;
disposing the dissolved manganese solution within an electrolytic cell, the electrolytic cell including an electrolytic cell anode and an electrolytic cell cathode;
applying a current between the electrolytic cell anode and the electrolytic cell cathode to the dissolved manganese solution, wherein applying the current forms a manganese dioxide (MnO 2 ) deposit upon the electrolytic cell anode;
harvesting the MnO 2 deposit from the electrolytic cell anode;
creating a manganese precursor by neutralizing the MnO 2 deposit and grinding the MnO 2 deposit to form an MnO 2 powder;
mixing the manganese precursor with a nickel precursor and a lithium precursor to create a mixture;
calcining the mixture to create a lithium manganese nickel oxide powder;
coating a current collector with the lithium manganese nickel oxide powder; and
disposing the separator and the electrolyte solution between the anode for the battery and the lithium manganese nickel oxide cathode to thereby form the battery,
wherein creating the manganese precursor further includes calcining the MnO 2 powder under one of atmospheric air and oxygen gas to create manganese (III) oxide (Mn 2 O 3 ); and
wherein the manganese precursor includes alkali metal impurities and alkaline earth metal impurities present in from 10 parts by weight to 100 parts by weight based on one million parts by weight of the manganese precursor.
2 . The method of claim 1 , wherein calcining the MnO 2 powder includes calcining the MnO 2 powder at a temperature of from 700° C. to 950° C. for from 1 hour to 24 hours.
3 . The method of claim 1 , wherein the manganese precursor includes particles having a diameter of at least 100 nanometers.
4 . The method of claim 1 , wherein the manganese precursor has a particle surface area of from 0.5 meters squared per gram to 5 meters squared per gram.
5 . The method of claim 1 , wherein calcining the mixture includes heating the mixture at a temperature of from 700° C. to 950° C. for from 1 hour to 24 hours.
6 . The method of claim 1 , wherein applying the current to the dissolved manganese solution includes applying a current density to the electrolytic cell anode and to the electrolytic cell cathode of from 10 amps per meter squared electrode surface area to 100 amps per meter squared electrode surface area.
7 . The method of claim 3 , wherein the manganese precursor includes particles having a diameter of from 100 nanometers to 300 nanometers.
8 . The method of claim 6 , wherein applying the current to the dissolved manganese solution includes applying a current density to the electrolytic cell anode and to the electrolytic cell cathode of from 27 amps per meter squared electrode surface area to 64.4 amps per meter squared electrode surface area.
9 . The method of claim 1 , wherein the lithium manganese nickel oxide cathode comprises lithium manganese nickel oxide (LiNi x Mn y O z ), wherein x=0.4-0.6, y=1.45-1.55, and z=3.8-4.0.
10 . The method of claim 9 , wherein the lithium manganese nickel oxide cathode comprises lithium manganese nickel oxide (LiNi 0.5 Mn 1.5 O 4 ).
11 . The method of claim 1 , wherein calcining the MnO2 powder includes calcining the McO2 powder at a temperature of from 700° C. to 850° C. for 12 hours.