The manufacturing of lithium battery packs involves a sophisticated process. The activation stage is the core环节 (key link/step) that determines the final performance, stability, and lifespan of the battery, mainly including key processes such as pre-charging, formation, aging, and constant capacity. As the final core process of the activation stage, aging testing directly affects the quality and safety of the lithium battery pack after it leaves the factory, making it an indispensable step in lithium battery production.
The effectiveness of battery aging is primarily determined by two core factors: aging temperature and aging time. Simultaneously, the sealed or open storage state during the battery aging process also subtly affects the internal chemical reaction process, ultimately impacting the overall battery performance.
Battery aging specifically refers to the static storage process after a lithium battery has been assembled, injection-molded, and completed its first charge. The industry categorizes aging into two types based on operating temperature: room temperature aging and high temperature aging. Professional ACEY battery aging machine can precisely adapt to the requirements of both aging modes, ensuring the standardized implementation of the aging process. The standard temperature for conventional room-temperature aging is 25℃, while there is no unified standard for high-temperature aging. Manufacturers set temperatures ranging from 38℃ to 45℃ depending on their product positioning. The industry-standard aging time is consistently between 48 and 72 hours, ensuring sufficient completion of the internal reactions within the battery.
The core purpose of aging testing for finished lithium-ion battery packs is to optimize the internal structure, stabilize electrochemical performance, and select high-quality cells, thereby mitigating potential problems in later use. This is manifested in three key aspects:
I. Promoting Full Electrolyte Wetting of the Cells
After lithium-ion battery assembly, the electrolyte cannot instantly and completely penetrate the pores of the positive and negative electrodes and the gaps in the separator. Prolonged static aging allows the electrolyte to slowly and evenly wet every part of the battery's internal structure, eliminating uneven wetting and effectively improving the discharge efficiency and capacity stability of the lithium-ion battery pack, preventing problems such as rapid capacity decay and uneven discharge in later stages.
II. Aging Quickly Stabilizes the Electrochemical System
After the first charge, lithium batteries contain unstable active materials, making them prone to side reactions such as trace electrolyte decomposition and gas evolution. Aging, especially temperature-controlled aging, actively accelerates these irreversible side reactions, allowing the positive and negative electrode active materials to quickly reach equilibrium. This thoroughly stabilizes the battery's internal electrochemical system, preventing performance fluctuations and voltage spikes during user operation, and significantly extending battery life.
III. Screening for Battery Consistency and Eliminating Defective Products
After the formation process, the battery's internal state is not yet stable, and measurements of voltage and internal resistance show significant deviations, making it impossible to accurately assess cell quality. After 48 to 72 hours of aging, parameters such as open-circuit voltage, internal resistance, and thickness tend to be constant. Workers can then use precise testing data to screen battery packs with high consistency, eliminating defective cells with excessive parameter deviations or hidden defects, ensuring the overall battery pack's matching and operational stability.
Compared to room temperature aging, high-temperature aging offers more significant optimization effects and is currently a core process for mainstream lithium battery manufacturers. The industry generally employs a process of aging at 45-50°C for 1-3 days, followed by resting at room temperature. High-temperature environments can further activate microscopic reactions within the battery, accelerating the exposure of potential defects such as abnormal voltage decay, cell thickness bulging, and abnormally high internal resistance. These parameter changes are core indicators for evaluating battery safety and electrochemical performance. Through high-temperature aging screening, substandard batteries can be identified in advance, allowing for control over the safety, quality, and operational stability of lithium battery packs from the production stage.
about us
Xiamen Acey New Energy Technology Co., Ltd. is a high-tech enterprise and specializes in the development of high-end equipment for lithium-ion batteries. Our business covers battery raw materials, lab-scale fabrication machines for coin cells, cylindrical cells and pouch cells, semi-automatic&full automatic battery pack assembly equipment, battery cell&pack testing systems, battery environmental safety testing equipment, etc.