1. An encoder spacer for a spindle motor comprising: a body in monolithic structure made of insulation material; a first terminal electrically connected to a main PCB (Printed Circuit Board) of the spindle motor and protruded from a lateral surface of the body; a second terminal electrically connected to the first terminal via a conduction path through the body, electrically connected to a first auxiliary PCB and protruded from an upper surface of the body; a substrate groove including an accommodation space for accommodating the encoder formed at an upper center of the body, wherein a second auxiliary PCB slides in the accommodation space by being inserted into channels at both sides of the accommodation space; and a third terminal exposed at the substrate groove for electrically connecting the second auxiliary PCB with the first terminal.
2. The encoder spacer of claim 1, wherein a bottom surface of the substrate groove is formed with a terminal groove, a support protruder is connected to a portion of the conduction path corresponding to the terminal groove, and wherein the third terminal includes a spring whose one end is inserted to the support protruder within the terminal groove, and a contact ball that is inserted to the other end of the spring.
3. An encoder spacer for a spindle motor comprising: a body in monolithic structure made of insulation material; a first terminal electrically connected to a main PCB (Printed Circuit Board) of the spindle motor; a second terminal electrically connecting a first auxiliary PCB mounted with an encoder and the first terminal; a third terminal electrically connecting a second auxiliary PCB mounted with an encoder and the first terminal; and a substrate groove formed by cutting a part of the body, wherein any one of the first auxiliary PCB and the second auxiliary PCB is fixed to the body at a mutually different position, and wherein the first auxiliary PCB is connected to the second terminal while being exposed to an upper side of the body, and the second auxiliary PCB is connected to the third terminal while being accommodated to the substrate groove.
4. The encoder spacer of claim 3, wherein the third terminal is electrically brought into contact with a conduction pattern exposed to both lateral surfaces of the second auxiliary PCB.
5. The encoder spacer of claim 3, wherein the third terminal is connected to a conduction path connecting the first and second terminals.
6. The encoder spacer of claim 5, wherein the third terminal includes a contact ball exposed to the substrate groove, and a spring elastically supporting the contact ball and electrically connecting the contact ball to the conduction path.
7. An encoder spacer for a spindle motor comprising: a body in monolithic structure made of insulation material; a first terminal electrically connected to a main PCB (Printed Circuit Board) of the spindle motor; a second terminal electrically connecting a first auxiliary PCB mounted with an encoder and the first terminal; and a third terminal electrically connecting a second auxiliary PCB mounted with an encoder and the first terminal, wherein any one of the first auxiliary PCB and the second auxiliary PCB is fixed to the body at a mutually different position, wherein the second terminal is inserted and soldered to the via hole formed at both peripheral margins of the first auxiliary PCB.
8. An encoder assembly comprising: an encoder; an encoder spacer including a body in monolithic structure made of insulation material, a first terminal electrically connected to a main PCB (Printed Circuit Board) of the spindle motor, a second terminal electrically connecting a first auxiliary PCB mounted with an encoder and the first terminal, and a third terminal electrically connecting a second auxiliary PCB mounted with an encoder and the first terminal, wherein any one of the first auxiliary PCB and the second auxiliary PCB is fixed to the body at a mutually different position, and wherein the encoder spacer further includes a substrate groove formed by cutting a part of the body, and wherein the first auxiliary PCB is connected to the second terminal while being exposed to an upper side of the body, and wherein the second auxiliary PCB is connected to the third terminal while being accommodated to the substrate groove.
9. The encoder assembly of claim 8, wherein the third terminal is electrically brought into contact with a conduction pattern exposed to both lateral surfaces of the second auxiliary PCB.
10. The encoder assembly of claim 8, wherein the third terminal is connected to a conduction path connecting the first and second terminals.
11. The encoder assembly of claim 10, wherein the third terminal includes a contact ball exposed to the substrate groove, and a spring elastically supporting the contact ball and electrically connecting the contact ball to the conduction path.
12. An encoder assembly comprising: an encoder; an encoder spacer including a body in monolithic structure made of insulation material, a first terminal electrically connected to a main PCB (Printed Circuit Board) of the spindle motor, a second terminal electrically connecting a first auxiliary PCB mounted with an encoder and the first terminal, and a third terminal electrically connecting a second auxiliary PCB mounted with an encoder and the first terminal, wherein any one of the first auxiliary PCB and the second auxiliary PCB is fixed to the body at a mutually different position, wherein the second terminal is inserted and soldered to a via hole formed at both peripheral margins of the first auxiliary PCB.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for making an oxygen reducing cathode catalyst, the method comprising:
(a) mixing a carbon source with a transition metal precursor to form a metal precursor loaded carbon substrate, wherein the substrate is substantially free of precious metals;
(b) adding a nitrogen precursor compound to the metal precursor loaded carbon substrate to form a carbon-metal-nitrogen precursor; and
(c) pyrolyzing the carbon-metal-nitrogen precursor at an elevated pressure ranging from about 2 bar to about 100 bar, thereby forming the oxygen reducing cathode catalyst.
2. The method of claim 1, wherein the carbon source comprises one or more of Norit\xae SX Ultra, Ketjenblack\xae, pyrolyzed perylene tetracarboxylic anhydride (PTCDA), polyacrylonitrile (PAN), Black Pearls\xae, Printex\xae XE2, pyrrole black, graphitic powder, acetylene black, Vulcan\xae XC72, oxidized carbon supports, and metal carbides.
3. The method of claim 1, wherein mixing the carbon source with a transition metal precursor further comprises stirring the carbon source with the transition metal precursor in a solvent for up to 12 hours and evaporating the solvent to form the carbon-metal substrate.
4. The method of claim 1, wherein the transition metal precursor is a transition metal macrocycle, a transition metal salt, or combination thereof.
5. The method of claim 4, wherein the transition metal macrocycle comprises cobalt pthalocyanine, iron pthalocyanine, cobalt tetraazannulene, iron tetramethoxy phenyl porpyrin chloride, tetracarboxylic cobalt, iron pthalocyanine, tetramethoxy phenyl porpyrin chloride, cobalt salen-N,N\u2032 bissalicylidine, ethylenediaminocobalt, cobalt-anten-O-amino, ferrocene, benzaldehyde, ethylenediamino cobalt, iron phenanthroline, or combinations thereof.
6. The method of claim 4, wherein the transition metal salt comprises (1) a cation selected from the group consisting of iron, cobalt, nickel, chromium, cerium, zinc, zirconium, molybdenum, manganese, and mixtures thereof; and (2) an anion selected from the group consisting of acetate, chloride, nitrate, sulfate, and combinations thereof.
7. The method of claim 6, wherein the transition metal salt comprises iron (II) acetate.
8. The method of claim 1, wherein the nominal amount of the metal precursor added to the carbon source to form said metal precursor loaded carbon substrate ranges from about 0.75% to about 10% by weight of the substrate.
9. The method of claim 1, wherein the transition metal precursor is a transition metal macrocycle, a transition metal salt, or combination thereof.
10. The method of claim 1, wherein the nitrogen precursor compound is selected from the group consisting of poly(quinoxaline), nitroaniline, 1,10 phenanthroline, pthalocyanine, pyridine, bipyridine, polyaniline, pyrrole, polyvinyl pyridine, 3-nitrophalimide, p-phenylazophenol, 6-quionoline carboxylic acid, 6-nitrobenzimidazole, 5-amino 6-nitro quinoline, 2,3 naphthalocyanine, 4,4\u2032-azoxydibenzoic acid, 2 amino 5-nitro pyrimidine, hematin, 4,4\u2032 azo-biscyanovaleric acid, heamotoporpyrin dihydrochloride, 4,4\u2032 nitrophenyl azo catechol 4,6 dihydroxy pyrimidine, nitrophenyl, benzylamine, 1,6 phenylendiamine, tetracyanoquinodimethane, propylene di-amine, ethylene di-amine, urea, selenourea, thiourea, dimethylformamide, tetrahydrofuran, ammonia, acetonitrile and polymers, and combinations thereof.
11. The method of claim 1, wherein the nitrogen precursor compound comprises melamine.
12. The method of claim 10, wherein the nominal amount of nitrogen in the carbon-metal-nitrogen precursor ranges from about 1.0% to about 15% by weight of the carbon-metal-nitrogen precursor.
13. The method of claim 1, wherein the nitrogen precursor compound is free of carbon.
14. The method of claim 1, wherein the nitrogen precursor compound undergoes a decomposition reaction to form ammonia.
15. The method of claim 14, wherein the nitrogen precursor compound comprises an ammonia generating precursor selected from the group consisting of ammonium hydroxide, urea, ammonium carbamate, or combinations thereof.
16. The method of claim 14, wherein the nitrogen precursor compound comprises an ammonium salt.
17. The method of claim 1, wherein the pyrolyzing step comprises pyrolyzing the carbon-metal-nitrogen precursor at a temperature ranging from about 600\xb0 C. to about 900\xb0 C. in a closed reaction vessel.
18. The method of claim 1, wherein the reaction vessel comprises quartz.
19. The method of claim 1, wherein the pyrolyzing step further comprises pyrolyzing the carbon-metal-nitrogen precursor using a spray pyrolysis apparatus.
20. A low temperature fuel cell comprising the oxygen reducing cathode catalyst of claim 1.
21. A method for making a membrane electrode assembly for a fuel cell, comprising:
(a) providing an ionomeric membrane, the membrane having a first side and a second side;
(b) applying an anode catalyst on at least a portion of the first side of the ionomeric membrane; and
(c) applying a cathode catalyst on at least a portion of the second side of the ionomeric membrane, wherein the cathode catalyst is synthesized by:
(i) mixing a carbon source with a transition metal precursor to form a metal precursor loaded carbon substrate, wherein the substrate is free of precious metals;
(ii) adding a nitrogen precursor compound to the metal precursor loaded carbon substrate to form a carbon-metal-nitrogen precursor;
(iii) pyrolyzing the carbon-metal-nitrogen precursor at a pressure ranging from about 2 bar to about 100 bar, thereby forming an oxygen reducing cathode catalyst, and
(iv) mixing the oxygen reducing cathode catalyst with a recast ionomer.
22. The method according to claim 21, wherein the anode catalyst comprises a catalyst ink having at least one transition metal selected from the group consisting of platinum, ruthenium, palladium, and combinations thereof.
23. The method according to claim 21, wherein the recast ionomer comprises poly(perfluorosulphonic acid).
24. A method for making a cathode catalyst coated diffusion layer for a fuel cell, comprising:
(a) providing a gas diffusion layer; and
(b) applying a cathode catalyst on at least a portion of the gas diffusion layer, wherein the cathode catalyst is synthesized by:
(i) mixing a carbon source with a transition metal precursor to form a metal precursor loaded carbon substrate, wherein the substrate is free of precious metals;
(ii) adding a nitrogen precursor compound to the metal precursor loaded carbon substrate to form a carbon-metal-nitrogen precursor; and
(iii) pyrolyzing the carbon-metal-nitrogen precursor at a pressure ranging from about 2 bar to about 100 bar, thereby forming an oxygen reducing cathode catalyst.
25. A method for making an oxygen reducing cathode catalyst, the method comprising:
(a) mixing a carbon source with a transition metal precursor to form a metal precursor loaded carbon substrate substantially free of precious metals;
(b) adding a nitrogen precursor compound having a N:C ratio of at least about 1:1 to the metal precursor loaded carbon substrate to form a carbon-metal-nitrogen precursor; and
(c) pyrolyzing the carbon-metal-nitrogen precursor at an elevated pressure ranging from about 2 bar to about 100 bar, thereby forming the oxygen reducing cathode catalyst.
26. The method according to claim 25, wherein the nitrogen precursor compound has a N:C ratio of at least about 2:1.
27. The method according to claim 25, wherein the nitrogen precursor compound comprises melamine.