Although fast charging technology accelerates battery wear and tear, modern BMS and materials science have significantly reduced the risks. Automakers can control the attenuation within a reasonable range through dynamic strategies and new technologies (such as silicon-carbon anodes and liquid cooling systems), and users only need to avoid extreme usage conditions to balance efficiency and lifespan.
Fast charging technology has been popular for many years, and its impact on batteries has always been a point of controversy. The answer is not absolute; it depends on the usage scenario and the compatibility with the technology. From the perspective of physical mechanisms, high-current charging will inevitably accelerate electrochemical reactions, causing problems such as lithium plating and polarization. However, breakthroughs in modern battery management systems (BMS) and materials science have significantly mitigated this risk.
The core contradiction of battery wear and tear lies in energy density and stability. Take lithium-ion batteries as an example. During fast charging, lithium ions need to intercalate into the negative electrode in an extremely short time. If the migration rate is insufficient, metallic lithium may precipitate, forming dendrites and piercing the separator. Experimental data shows that after 800 cycles of 10C fast charging , the capacity can decline by up to 25%. However, this data is based on extreme conditions in the laboratory. In daily use, car manufacturers keep the attenuation within a reasonable range by dynamically adjusting the charging strategy (such as segmental speed reduction).
Technological progress provides a buffer space for fast charging. For instance, CATL‘s second-generation Shenxing battery adopts silicon-carbon anode and liquid cooling technology, making 5-minute fast charging possible. Byd‘s megawatt flash charging system balances power and safety through a full-domain kilovolt high-voltage architecture and an intelligent temperature control system. The essence of these schemes is to enhance ion transport efficiency through material modification (such as carbon-coated graphite, single crystalline cathode) and structural optimization (such as ultrathin electrode), rather than relying solely on current intensity.
User behavior remains a variable that cannot be ignored. In the field of new energy vehicles, frequent fast charging when the battery level is below 20% will accelerate the deposition of lithium on the negative electrode. In the field of mobile phones, using non-original chargers may cause voltage fluctuations. Although BMS can monitor temperature and current in real time, it cannot completely counteract the impact of external factors. For instance, Huawei‘s fully liquid-cooled supercharging piles keep the temperature difference of the battery cells within 2℃. However, if the vehicle‘s heat dissipation design is outdated, local heat accumulation may still cause side effects.
Fast charging is available, but it needs to follow the technical boundaries. For new energy vehicles, it is recommended to mainly use slow charging, and fast charging to 80% is sufficient. For mobile phones, give priority to using the original charger and avoid high-temperature environments. In the future, as solid-state batteries (such as the sulfide all-solid-state battery equipped in the SAIC IM Motors L6) and integrated photovoltaic storage and charging facilities mature, the conflict between fast charging and battery life may be further diluted.
