About polymer lithium-ion batteries
1. Process (compared with hard-shell lithium-ion battery)
- Mixing, coating, production and winding processes are basically the same and can be universal and compatible
- The main process difference lies in the encapsulation process, the polymer uses aluminum-plastic film thermal encapsulation, hard-shell batteries
- Generally use laser welding and sealing
- The main equipment of liquid injection, chemical formation and testing processes are the same, but the jigs and fixtures are very different, which are generally regarded as incompatible.
2. Applications
- Consumer electronics: high energy density and safety characteristics of lithium-ion polymer batteries, widely used
- Electric vehicles: the use of relatively harsh environment, due to the fragile aluminum-plastic film packaging of polymer batteries, easy to bruise damage, as well as the long-term reliability of thermal packaging, generally not used
- Energy storage batteries: long-term reliability problems, and generally rarely use lithium-ion polymer batteries
At present, the vast majority of domestic polymer batteries are actually soft packaging liquid lithium-ion batteries!
EV battery and ordinary lithium-ion battery technology comparison
1. New and old
(1) Old, old technology: the same basic principle and structure as ordinary lithium-ion batteries
(2) New, new applications, new materials
- New applications: for vehicles, energy storage power plants
- New materials: lithium iron phosphate, lithium titanate, hard carbon... 2.
2. Large and small (Capacity, Size, Rate, Power)
(1) small: ordinary lithium-ion battery capacity <3Ah
(2) Large capacity: 10Ah, 20Ah, 50Ah, 60Ah...
(3) Large size:
- Thickness: 10mm, 25mm...
- Width: 70mm, 110mm, 135mm...
- Length: 110mm, 150n, 270mm...
(4) Large magnification
- Working magnification: EV: 0.5C, PHEV: 2C, HEV: 10C
- Peak multiplier: EV: 2C, PHEV: 5C, HEV: 20C
(5) High power.
- Power density at 25℃ With 10s HPPC≈1100W/kg
- 30℃ discharge power > 10% of 25℃'s
3. static and dynamic (Reliability)
(1) static: ordinary lithium-ion battery use environment is relatively static
(2)Dynamic: vehicle environment, vibration, acceleration and braking, climate...
(3)EV battery reliability study
- Mechanical performance: Anti-nailing, anti-extrusion, anti-pulling, anti-drop
- Battery temperature rise: 3C times the working rate, the battery temperature rise does not exceed 25℃
- Battery operating temperature: -30℃~60℃
- Battery module heat dissipation design: battery heat simulation, air cooling, water cooling solution, oil cooling solution
4. Long and short
(1)Short: 3000 cycles for general common Li-ion battery
(2) Long: EV battery life 1500~2000cycles
5. Complexity and simplicity (BMU, BMS)
(1)Simple: ordinary lithium-ion batteries are used singly and only need simple protection
(2) complicated: BMU, BMS, multi-string, multi-parallel, capacity calculation, temperature control, power balance...
6. high and low (Productioncapability, Safety)
(1) low: ordinary lithium-ion battery single use, the product consistency requirements are not high
(2) High: High consistency (process capability), high safety
(3)EV battery safety performance reference standards: USABC, GB
EV battery consistency requirements
Capacity consistency (Cap)
Resistance consistency (internal resistance, connection resistance)
Voltage consistency (OCV)
Capacity consistency (SOC)
Self-discharge consistency (Kvalue)
Voltage curve consistency (Voltage curve)
Temperature rise (Temp. rise)
The major automobile manufacturers have "joined hands" with well-known battery manufacturers, or joint ventures, or joint research and development, or acquisition ... The high manufacturing capacity requirements of power batteries will eventually go in the direction of standardization, and the current power battery manufacturing is in the "land grabbing, position taking" stage. The current power battery manufacturing is in the stage of "grabbing land and occupying position", who has seized the first opportunity to occupy the first chip, who may be the future "standard" and occupy a favorable position in the competition.
EV process flow introduction
1.Electrode.
- Powder Mixing System
- High Viscosin Mixer
- Coater
- Cold Presser
- Auto slitting
2. Assembly:
- Auto Winding
- Auto X-ray inspector
- Auto Assembly Line
- Laser Welding
- Auto Injector
- CanCleaner
3.Testing.
- Formation Equipment
- Auto Degassing
- Capacity Taster
- IMP/OCV Tester
- High Rate Tester
- Auto Grouping
