Development status of A123's 12Vu002648V advanced automotive battery technology
The research and development of the 12V low voltage system (the main focus is on reducing the impedance of the battery)
Car start-up batteries and 48V system batteries require higher power characteristics of the battery, so the impedance of the battery must be reduced. And it is necessary to reduce the impedance in a relatively wide temperature range, which has been achieved through the development of more advanced LFP materials and customized electrolytes.
Figure 1 Roadmap of A123 impedance reduction (nanophosphate/superphosphate/next generation)
12V start-up battery system performance relative to lead-acid There are great advantages in battery performance and cost.
Figure 2 Comparison of cold start current and lead-acid battery (7.5V 10S)
48V high voltage system (high energy density system)
Development strategy: Focus on the positive electrode/negative electrode/separator/electrolyte to improve battery energy density,
Technical node: 180Wh/kg ternary battery technology has been mass-produced, 230Wh/kg uses high Ni ternary material The project will be realized at the end of 2017, 250Wh/kg using A123 advanced anode technology and high Ni ternary material project is underway.
Figure 3 Technology node roadmap
230Wh/kg technical project goal:
energy density>u003d230Wh/kg,< /p>
Cycle life: normal temperature 25℃>u003d2000 times, high temperature 45℃>u003d1200 times
Power density:>u003d2000W/kg
Pass the national standard abuse test , And successfully transferred to vector production.
Project achieved:
Maintain a good cycle under the condition of 4.4V charging.
The morphology of NMC 523 is modified to increase the safety window.
The diaphragm adopts optimized ceramic morphology and coated with a new binder
Abuse test (EUCAR) Figure 4 230Wh/kg battery performance 250Wh/kg (600Wh/L) technology The choice of multiple technical solutions can reduce risks And better adapt to the ever-changing trends of the market. Figure 5 Multiple technology platforms are available Figure 6 Current performance of 250Wh/kg Safety performance Anode strategy: coating and doping of active material, modification of pole piece. Figure 7 Modification of cathode material Figure 8 Acupuncture experiment before and after anode modification Electrolyte: delay thermal runaway under overcharged state, increase flash point and electrolyte burning temperature; Isolation membrane: use the most advanced isolation membrane technology. Figure 9 Overcharge performance of electrolyte and positive electrode before and after modification