Summary of the invention
The object of the present invention is to provide a kind of water-system waste lithium-ion-power cell to prepare the method for LiFePO4.
Be the realization above-mentioned purpose, the method for preparing iron lithium phosphate by recovering water-system waste lithium-ion power battery provided by the invention, key step is:
1) fractionation of water-system waste lithium-ion-power cell: with the water-system waste lithium ion battery through overdischarge, shell, take out electric core, electric core is carried out shearing-crushing after, handle by deionized water, sieve and reclaim electrode material and conductive agent mixture.
2) separation of positive and negative electrode material: the electrode material and the conductive agent mixture of step 1 are handled under 20 ℃-100 ℃ through the inorganic acid that adds 0.1-5M after the drying, and the solid-to-liquid ratio of mixed liquor is 5-50g/L; Filtration obtains containing Li
+, Fe
2+, PO
4 3-Acid solution.
3) LiFePO
4Thick product is synthetic: contain Li to 1L
+, Fe
2+, PO
4 3-Acid solution in to add 50ml-950ml concentration be lithium salts or the molysite of 1M, make mol ratio n
Li+: n
Fe2+: n
PO43-=0.8-1.2: 1: 1, add ascorbic acid 10g-200g, stirred 1 hour-3 hours down at 50 ℃-100 ℃, in whipping process, with ammoniacal liquor control pH value=3-7; Filter, obtain deposition;
4) LiFePO
4Synthetic: the LiFePO that step 3 is obtained
4Thick product is pressed quality than sucrose: LiFePO
4The ratio of thick product=5%-45% joins carries out ball milling, the LiFePO that drying and calcining obtains regenerating in the aqueous sucrose solution
4Material.
Described method, wherein the deionized water in the step 1 is handled, and is 1g electricity core fragment is added the 30ml-100ml deionized water, and 20 ℃-100 ℃ are stirred down or sonic oscillation 1 hour-3 hours.
Described method, wherein the inorganic acid in the step 2 comprises the mixed solution of hydrochloric acid, sulfuric acid or hydrochloric acid and sulfuric acid.
Described method, wherein the lithium salts in the step 3 is selected from lithium sulfate, lithium hydroxide, lithium chloride or lithium nitrate.
Described method, wherein the molysite in the step 3 is selected from ferrous sulfate, frerrous chloride or ferric nitrate.
Described method, wherein the drying and calcining in the step 4 is at N
2Protection was calcined 1 hour-24 hours in 600 ℃-900 ℃ down.
Method from preparing iron lithium phosphate by recovering water-system waste lithium-ion power battery provided by the invention; Effectively reclaim and utilized again electrokinetic cell; Not only reclaimed copper, aluminium, and prepared the new LiFePO4 electrode material of lithium again, solved the water system lithium iron phosphate battery and reclaimed problem.Reduced the production cost of battery enterprise, realized the recycle of waste and old water system lithium iron phosphate electrokinetic cell electrode material to a certain extent, effect is obvious, the technology simple possible.
Embodiment
To lacking this present situation of a kind of effective method to reclaim the preparation LiFePO4 from the water-system waste lithium iron phosphate dynamic battery at present; Low cost provided by the invention; Simple to operate; The waste lithium iron phosphate electrokinetic cell that does not produce secondary pollution reclaims the method for preparing LiFePO4, and concrete steps comprise:
(1) with waste and old lithium ion battery through overdischarge, shell, take out electric core, electric core is carried out shearing-crushing after, handle by deionized water, 1g electricity core fragment adds the 30ml-100ml deionized water, under 20 ℃-100 ℃, stirs or sonic oscillation 1 hour-3 hours.Sieve then and reclaim electrode material and conductive agent mixture.
(2) inorganic acid that adds 0.1-5M after electrode material and the conductive agent mixture drying is handled under 20 ℃-100 ℃, and the solid-to-liquid ratio of mixed liquor is 5-50g/L.Filtration obtains Li
+, Fe
2+, PO
4 3-Acid solution.
(3) contain Li to 1L
+, Fe
2+, PO
4 3-Acid solution in to add 50ml-950ml concentration be lithium salts or the molysite of 1M, make n
Li+: n
Fe2+: n
PO43-=0.8-1.2: 1: 1, add ascorbic acid 10g-200g, under 50 ℃-100 ℃, stirred 1 hour-3 hours, in whipping process, with concentration ammoniacal liquor control pH value=3-7.Filter, obtain deposition.
(4) LiFePO
4Synthetic: as will to go up the deposition that a step obtains and join in the aqueous sucrose solution sucrose quality: deposition mass ratio=5%-45%.Above-mentioned mixture is carried out ball milling, drying, the powder that obtains is at N
2Under the protection, temperature is 600 ℃-900 ℃ calcinings 1 hour-24 hours, the LiFePO that obtains regenerating
4Electrode material.Calcining, the LiFePO that obtains regenerating
4Material.
Below in conjunction with embodiment the present invention is elaborated
Embodiment 1
Waste and old water system lithium iron phosphate electrokinetic cell is shelled to battery through after the discharge process, take out electric core, carry out Mechanical Crushing; With waste and old lithium ion battery through overdischarge, shell, take out electric core, electric core is carried out shearing-crushing after, take by weighing 200g electricity core fragment; Add the 6L deionized water, under 20 ℃, stir and sieved afterwards in 1 hour; Sieve top is divided into collector, and the lower part of screen is divided into electrode material and conductive agent mixture.With the hydrochloric acid that adds 0.1M after electrode material and the conductive agent mixture drying, the solid-to-liquid ratio of mixed liquor is 50g/L.Stir down at 20 ℃, make it abundant reaction, filter and obtain Li
+, Fe
2+, PO
4 3-Acid solution.Contain Li to 1L
+, Fe
2+, PO
4 3-Acid solution in to add 50ml concentration be the LiOH of 1mol/L, make n
Li+: n
Fe2+: n
PO43-=0.8: 1: 1, add ascorbic acid 10g, under 50 ℃, stirred 1 hour, the pH value with ammoniacal liquor is regulated mixed solution makes pH=5.0.Filter, obtain deposition.Take by weighing 9g sucrose, be dissolved in the deionized water, take by weighing the deposition 20g that a step obtains, above-mentioned mixture is carried out ball milling, drying, the powder that obtains is at N
2Under the protection, temperature is 600 ℃ of calcinings 24 hours, the LiFePO that obtains regenerating
4Electrode material.The LiFePO 4 material that reclaims with this method has good electrochemical, is 130mAH/g in the 0.2C discharge capacity, and 50 capability retentions of charge and discharge cycles are 94%.The LiFePO 4 material of regeneration has good crystalline structure.
Embodiment 2
Waste and old water system lithium iron phosphate electrokinetic cell is shelled to battery through after the discharge process, take out electric core, carry out Mechanical Crushing; With waste and old lithium ion battery through overdischarge, shell, take out electric core; After electric core carried out shearing-crushing, take by weighing 100g electricity core fragment, add the 10L deionized water; Under 100 ℃, stir the back of sieving afterwards in 3 hours and reclaim electrode material and conductive agent mixture.With the sulfuric acid that adds 5M after electrode material and the conductive agent mixture drying, the solid-to-liquid ratio of mixed liquor is 5g/L.Stir down at 100 ℃, make it abundant reaction, filter and obtain Li
+, Fe
2+, PO
4 3-Acid solution.Contain Li to 1L
+, Fe
2+, PO
4 3-Acid solution in to add 950ml concentration be the LiOH of 1mol/L, make n
Li+: n
Fe2+: n
PO43-=1.2: 1: 1, add ascorbic acid 200g, under 100 ℃, stirred 1 hour, the pH value with ammoniacal liquor is regulated mixed solution makes pH=6.0.Filter, obtain deposition.Take by weighing 1.25g sucrose, be dissolved in the deionized water, take by weighing the deposition 25g that a step obtains, above-mentioned mixture is carried out ball milling, drying, the powder that obtains is at N
2Under the protection, temperature is 900 ℃ of calcinings 12 hours, the LiFePO that obtains regenerating
4Electrode material.The LiFePO 4 material that reclaims with this method has good electrochemical, is 135mAH/g in the 0.2C discharge capacity, and 50 capability retentions of charge and discharge cycles are 95.6%.
Embodiment 3
Waste and old water system lithium iron phosphate electrokinetic cell is shelled to battery through after the discharge process, take out electric core, carry out Mechanical Crushing; With waste and old lithium ion battery through overdischarge, shell, take out electric core; After electric core carried out shearing-crushing, take by weighing 1Kg electricity core fragment, add the 50L deionized water; Under 50 ℃, stir the back of sieving afterwards in 2 hours and reclaim electrode material and conductive agent mixture.With the sulfuric acid that adds 3M after electrode material and the conductive agent mixture drying, the solid-to-liquid ratio of mixed liquor is 20g/L.Stir down at 60 ℃, make it abundant reaction, filter and obtain Li
+, Fe
2+, PO
4 3-Acid solution.Contain Li to 1L
+, Fe
2+, PO
4 3-Acid solution in to add 500ml concentration be the ferrous sulfate of 2mol/L, make n
Li+: n
Fe2+: n
PO43-=1.2: 1: 1, add ascorbic acid 150g, under 80 ℃, stirred 2 hours, the pH value with ammoniacal liquor is regulated mixed solution makes pH=6.0.Filter, obtain deposition.Take by weighing 10g sucrose, be dissolved in the deionized water, take by weighing the deposition 200g that a step obtains, above-mentioned mixture is carried out ball milling, drying, the powder that obtains is at N
2Under the protection, temperature is 750 ℃ of calcinings 3 hours, the LiFePO that obtains regenerating
4Electrode material.The LiFePO 4 material that reclaims with this method has good electrochemical, is 125mAH/g in the 0.2C discharge capacity, and 50 capability retentions of charge and discharge cycles are 96.7%.
Embodiment 4
Waste and old water system lithium iron phosphate electrokinetic cell is shelled to battery through after the discharge process, take out electric core, carry out Mechanical Crushing; With waste and old lithium ion battery through overdischarge, shell, take out electric core; After electric core carried out shearing-crushing, take by weighing 1.5Kg electricity core fragment, add the 60L deionized water; Under 70 ℃, sonic oscillation reclaims electrode material and conductive agent mixture after sieving after 1.5 hours.With the sulfuric acid that adds 4M after electrode material and the conductive agent mixture drying, the solid-to-liquid ratio of mixed liquor is 35g/L.Stir down at 55 ℃, make it abundant reaction, filter and obtain Li
+, Fe
2+, PO
4 3-Acid solution.Contain Li to 1L
+, Fe
2+, PO
4 3-Acid solution in to add 350ml concentration be the ferrous sulfate of 1mol/L, make n
Li+: n
Fe2+: n
PO43-=1: 1: 1, add ascorbic acid 100g, under 80 ℃, stirred 2 hours, the pH value with ammoniacal liquor is regulated mixed solution makes pH=5.0.Filter, obtain deposition.Take by weighing 20g sucrose, be dissolved in the deionized water, take by weighing the deposition 250g that a step obtains, above-mentioned mixture is carried out ball milling, drying, the powder that obtains is at N
2Under the protection, temperature is 750 ℃ of calcinings 10 hours, the LiFePO that obtains regenerating
4Electrode material.The LiFePO 4 material that reclaims with this method has good electrochemical, is 145mAH/g in the 0.2C discharge capacity, and 50 capability retentions of charge and discharge cycles are 94.7%.