Power battery and positive electrode plate thereof
The present invention provides a power battery and a positive electrode plate thereof. The positive electrode plate includes a positive current collector and a positive active material layer formed on the positive current collector. The positive active material layer contains a mixture of lithium iron phosphate and FeF 3 , or a mixture of lithium iron phosphate and LiFe 2 F 6 , or a mixture of lithium iron phosphate, FeF 3 and LiFe 2 F 6 . FeF 3 or LiFe 2 F 6 has a high gram capacity of more than 200 mAh/g and has a charge and discharge interval close to that of lithium iron phosphate, which can improve the energy density and the safety performance of the power battery.
1. A power battery, comprising:
a battery case; and
a positive electrode plate, a negative electrode plate, a separator, and an electrolyte housed in the battery case;
wherein the positive electrode plate comprises a positive current collector and a positive active material layer formed on the positive current collector, the positive active material layer contains a mixture of lithium iron phosphate and FeF 3 , or a mixture of lithium iron phosphate and LiFe 2 F 6 , or a mixture of lithium iron phosphate, FeF 3 and LiFe 2 F 6 , and wherein the negative electrode plate comprises a layer of lithium powder on a surface thereof, the lithium powder is capable of providing lithium source for FeF 3 and/or LiFe 2 F 6 in the positive electrode plate, and a mass ratio of lithium powder to (FeF 3 +LiFe 2 F 6 ) is more than 1.
2. The power battery according to claim 1 , wherein a weigh content of lithium iron phosphate in the positive active material is 5%-95%.
3. The power battery according to claim 1 , wherein a weigh content of lithium iron phosphate in the positive active material is 50%-90%.
4. The power battery according to claim 1 , wherein a weigh content of the positive active material in the positive active material layer is 85%-98%.
5. The power battery according to claim 4 , wherein the positive active material layer comprises a conductive agent and a binder.
6. The power battery according to claim 5 , wherein a weight content of the conductive agent in the positive active material layer is 1%-5%.
7. The power battery according to claim 5 , wherein a weight content of the binder in the positive active material layer is 1%-10%.
8. The power battery according to claim 5 , wherein the conductive agent is selected from a group consisting of acetylene black, flake graphite and conductive carbon black.
9. The power battery according to claim 5 , wherein the binder is polyvinylidene fluoride.