Lithium Battery Ageing: Is Full Charge Dangerous?
The manufacturing of lithium batteries encompasses three key stages: electrode production, cell packaging, and battery activation. Specifically, the activation process ensures full engagement of active substances with the electrolyte, promising stable electrochemical performance. This stage incorporates pre-charging, formation, and aging of lithium batteries, each step critical to maintaining optimal battery conditions.
Understanding the Aging Process of Lithium Batteries
Aging in lithium batteries involves storing them post-chemical charging and discharging. This step, conducted at room or elevated temperatures, is pivotal in ensuring performance stability. It facilitates full electrolyte penetration into electrode sheets, stabilizes the SEI film on the graphite negative electrode, and expedites the stabilization of electrochemical performance by accelerating potential side effects like gas production and electrolyte breakdown.
Key Factors in Lithium Battery Aging
- State of Charge (SOC): The charge level of a lithium battery affects its aging rate and voltage drop. Tests under specific charging conditions are common.
- Storage Temperature: Temperature critically impacts the self-discharge rate and chemical reaction rate in lithium batteries.
- Aging Duration: Extended aging times, especially at high temperatures (e.g., 45°C for 7 days), are energy-intensive.
Risks of Full Charge in Lithium Battery Aging
Chunpeng Zhao et al.'s research highlights the dangers associated with high SOC in lithium batteries. They created thermal shocks to induce explosions in lithium batteries, noting that higher SOC levels reduce time to explosion while increasing temperature and pressure outcomes. Specifically, a lithium battery at 100% SOC poses a significantly higher explosion risk, warranting careful evaluation of safety hazards during the activation process.
Concluding Thoughts
The process of lithium battery activation must balance operational processes with safety to prevent potential explosions. High-energy density in large batteries necessitates scrupulous attention to thermal safety, ensuring that fires and explosions are proactively avoided.