Positive electrode for lithium secondary batteries and lithium secondary battery
A technology for lithium secondary batteries and positive electrodes, which is applied in the field of positive electrodes and lithium secondary batteries, can solve the problems of low energy density, high specific surface area, and high energy density, and achieve the effects of high energy density, excellent rate characteristics, and excellent cycle life.
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0096]
[0097] First, LiMn, which is an olivine Mn-based positive electrode active material, was synthesized as follows 0.8 Fe 0.2 PO 4 .
[0098] 14.4g NH 4 h 2 PO 4 , 5.55g LiOH·H 2 O, 17.9g MnC 2 o 4 2H 2 O and 4.50 g FeC 2 o 4 2H 2 O was mixed, dextrin was added thereto to make the dextrin 12% by mass, balls for pulverization made of zirconia were put into a tank made of zirconia, and mixed using a planetary ball mill. This mixed powder was put into an alumina crucible, and precalcined at 400° C. for 10 hours under an argon flow of 0.3 L / min. The obtained precalcined body was pulverized once with an agate mortar, put into an alumina crucible again, and main calcined at 700° C. for 10 hours under an argon flow of 0.3 L / min. After the main calcination, the obtained powder is crushed with an agate mortar, and the particle size is adjusted with a 45 μm mesh sieve to obtain the composition formula LiMn 0.8 Fe 0.2 PO 4 indicated material.
[0099] X-ray diffr...
Embodiment 2
[0127] In Example 2, the composition of the active material was changed to LiMn 0.3 Fe 0.7 PO 4 . 14.4gNH 4 h 2 PO 4 , 5.37g LiOH·H 2 O, 6.71g MnC 2 o 4 2H 2 O and 15.7 g FeC 2 o 4 2H 2 O mixed to synthesize LiMn 0.3 Fe 0.7 PO 4 , except that, the same operations as in Example 1 were performed to prepare the positive electrode sheet, evaluate the powder physical properties of the material, and evaluate the mechanical and electrochemical characteristics of the electrode.
[0128] The result of the pH measurement of the active substance, the pH is 11.01, the result of the measurement of the specific surface area of the active substance, the specific surface area is 35m 2 / g.
[0129] Gelation of the slurry before coating was not observed, and the state was good. No cracks occurred in the flexibility measurement (bending test), and the evaluation result of the peeling test was 0. The rate test result was 80%, and the capacity retention rate after 100 cycles in...
Embodiment 3
[0132] In Example 3, the composition of the active material was changed to LiMnPO 4 . 14.4gNH 4 h 2 PO 4 , 5.67g LiOH·H 2 O and 22.4 g MnC 2 o 4 2H 2 O mixed to synthesize LiMnPO 4 , except that, the same operations as in Example 1 were performed to prepare the positive electrode sheet, evaluate the powder physical properties of the material, and evaluate the mechanical and electrochemical characteristics of the electrode.
[0133] The result of the pH measurement of the active substance, the pH is 11.2, the result of the measurement of the specific surface area of the active substance, the specific surface area is 42m 2 / g.
[0134] Gelation of the slurry before coating was not observed, and the state was good. No cracks occurred in the flexibility measurement (bending test), and the evaluation result of the peeling test was 0. The rate test result was 48%, and the capacity retention rate after 100 cycles in the cycle test was over 99%.
[0135] From the above r...
PUM
| Property | Measurement | Unit |
|---|---|---|
| specific surface area | aaaaa | aaaaa |
| specific surface area | aaaaa | aaaaa |
| specific surface area | aaaaa | aaaaa |
Abstract
Description
Claims
Application Information
Login to View More