Method for synthesizing doped type lithium iron phosphate

Abstract

The invention discloses a method for synthesizing doped lithium iron phosphate, comprising the steps as follows: 1) ferrite, lithium salt, phosphonium salt and metal oxide are taken by proportion and ball-grinded in air for 1-10 hours by taking ethanol as medium; the gained mixture is dried, arranged in a pipe-typed furnace and reacts for 4-8 hours under the protection of protective gas and at the temperature of 300-400 DEG C; 2) ball grinding is carried out on the mixture of the gained lithium iron phosphate former body and carbon source for 1-10 hours by taking the ethanol as medium; 3) after the gained outcome is wrapped by tinfoil and arranged in a crucible which is filled with graphite, the crucible is arranged in a microwave oven and heated for 5-30 minutes under the microwave power of 100-800W; the crucible is cooled for 1-5 minutes when the heating is stopped; 4) the crucible is heated for 1-10 minutes by the micro-wave power of 100-800W, the crucible is cooled for 1-5 minutes, when the heating is stopped; 5) step 4) is repeatedly done for 1-10 times and the finished product is gained after natural cooling. The method has the advantages of simple process, short reaction time, high purity of the product and high vibration density, and the like.

Description

1. Technical field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for synthesizing doped lithium iron phosphate. 2. Background technology

[0002] At present, lithium-ion batteries occupy a leading position in the secondary battery market, and the positive electrode active material of mainstream products is mainly LiCoO 2 . However, as a strategic resource, cobalt is very scarce, expensive, toxic, and highly polluting. Therefore, the battery industry has been working hard to find alternatives to LiCoO 2 positive electrode material. In 1997, the Goodenough group reported for the first time that lithium iron phosphate with an olivine structure could reversibly intercalate and deintercalate lithium ions, which attracted widespread attention. LiFePO with olivine structure 4 As a new type of lithium-ion battery cathode material, it has the advantages of wide material sources, low price, high theoretical specific...

Examples

Embodiment 1

[0024] Embodiment 1: (1) get lithium carbonate 3.621g, self-made ferrous oxalate (FeC 2 o 2 2H 2 O) 17.82g, ammonium dihydrogen phosphate 11.5g, lanthanum nitrate 0.325g, magnesium hydroxide 0.116g, using ethanol as medium, ball mill in air for 5 hours, and dry the mixture at 100°C.

[0025] (2) The product obtained in step (1) was placed in a tube furnace, and reacted for 5 hours at a temperature of 350° C. under the protection of nitrogen to obtain a lithium iron phosphate precursor.

[0026] (3) Mix 4 g of glucose with the obtained lithium iron phosphate precursor, use ethanol as a medium after mixing, ball mill in air for 2 hours, and dry the mixture at 100° C. for later use.

[0027] (4) The product obtained in the step (3) is wrapped with tin foil, and after being placed in a crucible full of graphite, the crucible is put into a microwave oven, heated for 5 minutes with a microwave power of 480W, and cooled for 1 minute after stopping.

[0028] (5) Heat for 2 minutes ...

Embodiment 2

[0031] Embodiment 2: (1) get lithium hydroxide 4.112g, self-made ferrous oxalate (FeC 2 o 2 2H 2 O) 17.82g, diammonium hydrogen phosphate 13.2g, neodymium nitrate 0.33g, zinc hydroxide 0.198g, using ethanol as medium, ball mill in air for 5 hours, and dry the mixture at 100°C.

[0032] (2) The product obtained in step (1) was placed in a tube furnace, and reacted for 5 hours at a temperature of 350° C. under the protection of argon to obtain a lithium iron phosphate precursor.

[0033] (3) Mix 4 g of polyvinylidene fluoride with the obtained lithium iron phosphate precursor, use ethanol as a medium after mixing, ball mill in air for 2 hours, and dry the mixture at 100° C. for use.

[0034] (4) The product obtained in the step (3) is wrapped with tin foil, and after being placed in a crucible full of graphite, the crucible is put into a microwave oven, heated for 5 minutes with a microwave power of 640W, and cooled for 1 minute after stopping.

[0035] (5) Then heat with 640...

Embodiment 3

[0038] Embodiment 3: (1) get lithium carbonate 3.621g, self-made ferrous oxalate (FeC 2 o 2 2H 2 O) 16.2g, ammonium dihydrogen phosphate 11.5g, manganese acetate 1.73g, magnesium hydroxide 0.116g, using ethanol as medium, ball mill in air for 5 hours, and dry the mixture at 100°C.

[0039] (2) The product obtained in step (1) was placed in a tube furnace, and reacted for 5 hours at a temperature of 350° C. under the protection of nitrogen to obtain a lithium iron phosphate precursor.

[0040] (3) Mix 4 g of glucose with the obtained lithium iron phosphate precursor, use ethanol as a medium after mixing, ball mill in air for 2 hours, and dry the mixture at 100° C. for later use.

[0041] (4) The product obtained in the step (3) is wrapped with tin foil, and after being placed in a crucible full of graphite, the crucible is put into a microwave oven, heated for 5 minutes with a microwave power of 480W, and cooled for 1 minute after stopping.

[0042] (5) Then heat for 2 minut...

1. Technical field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for synthesizing doped lithium iron phosphate. 2. Background technology

[0002] At present, lithium-ion batteries occupy a leading position in the secondary battery market, and the positive electrode active material of mainstream products is mainly LiCoO 2 . However, as a strategic resource, cobalt is very scarce, expensive, toxic, and highly polluting. Therefore, the battery industry has been working hard to find alternatives to LiCoO 2 positive electrode material. In 1997, the Goodenough group reported for the first time that lithium iron phosphate with an olivine structure could reversibly intercalate and deintercalate lithium ions, which attracted widespread attention. LiFePO with olivine structure 4 As a new type of lithium-ion battery cathode material, it has the advantages of wide material sources, low price, high theoretical specific...

Examples

Embodiment 1

[0024] Embodiment 1: (1) get lithium carbonate 3.621g, self-made ferrous oxalate (FeC 2 o 2 2H 2 O) 17.82g, ammonium dihydrogen phosphate 11.5g, lanthanum nitrate 0.325g, magnesium hydroxide 0.116g, using ethanol as medium, ball mill in air for 5 hours, and dry the mixture at 100°C.

[0025] (2) The product obtained in step (1) was placed in a tube furnace, and reacted for 5 hours at a temperature of 350° C. under the protection of nitrogen to obtain a lithium iron phosphate precursor.

[0026] (3) Mix 4 g of glucose with the obtained lithium iron phosphate precursor, use ethanol as a medium after mixing, ball mill in air for 2 hours, and dry the mixture at 100° C. for later use.

[0027] (4) The product obtained in the step (3) is wrapped with tin foil, and after being placed in a crucible full of graphite, the crucible is put into a microwave oven, heated for 5 minutes with a microwave power of 480W, and cooled for 1 minute after stopping.

[0028] (5) Heat for 2 minutes ...

Embodiment 2

[0031] Embodiment 2: (1) get lithium hydroxide 4.112g, self-made ferrous oxalate (FeC 2 o 2 2H 2 O) 17.82g, diammonium hydrogen phosphate 13.2g, neodymium nitrate 0.33g, zinc hydroxide 0.198g, using ethanol as medium, ball mill in air for 5 hours, and dry the mixture at 100°C.

[0032] (2) The product obtained in step (1) was placed in a tube furnace, and reacted for 5 hours at a temperature of 350° C. under the protection of argon to obtain a lithium iron phosphate precursor.

[0033] (3) Mix 4 g of polyvinylidene fluoride with the obtained lithium iron phosphate precursor, use ethanol as a medium after mixing, ball mill in air for 2 hours, and dry the mixture at 100° C. for use.

[0034] (4) The product obtained in the step (3) is wrapped with tin foil, and after being placed in a crucible full of graphite, the crucible is put into a microwave oven, heated for 5 minutes with a microwave power of 640W, and cooled for 1 minute after stopping.

[0035] (5) Then heat with 640...

Embodiment 3

[0038] Embodiment 3: (1) get lithium carbonate 3.621g, self-made ferrous oxalate (FeC 2 o 2 2H 2 O) 16.2g, ammonium dihydrogen phosphate 11.5g, manganese acetate 1.73g, magnesium hydroxide 0.116g, using ethanol as medium, ball mill in air for 5 hours, and dry the mixture at 100°C.

[0039] (2) The product obtained in step (1) was placed in a tube furnace, and reacted for 5 hours at a temperature of 350° C. under the protection of nitrogen to obtain a lithium iron phosphate precursor.

[0040] (3) Mix 4 g of glucose with the obtained lithium iron phosphate precursor, use ethanol as a medium after mixing, ball mill in air for 2 hours, and dry the mixture at 100° C. for later use.

[0041] (4) The product obtained in the step (3) is wrapped with tin foil, and after being placed in a crucible full of graphite, the crucible is put into a microwave oven, heated for 5 minutes with a microwave power of 480W, and cooled for 1 minute after stopping.

[0042] (5) Then heat for 2 minut...