What Are the Causes of Lithium Battery Degradation?

[McWilliam]

Lithium battery capacity degradation occurs due to the following reasons: 1. Lithium battery abuse: When the State of Charge (SOC) is below 120%, there is no significant capacity loss. However, when SOC exceeds 120%, lithium deposition begins at the anode, and due to the formation of a thicker SEI film, impedance increases, leading to the loss of active lithium. Continued overcharging can cause thermal runaway in lithium batteries. At excessively high SOC levels, the decomposition rate of the electrolyte accelerates, forming a thick deposition layer on the graphite anode, which contains precipitated lithium. High-rate charging and discharging also contribute to capacity loss, as the cathode and anode undergo volume contraction and expansion during the process. The larger the charging and discharging current, the more intense the contraction and expansion, leading to greater stress. Consequently, particles in the cathode and anode are more prone to fracture or detachment from the current collector due to rapid volume changes, accelerating cycle degradation. 2. Temperature factors: The usage environment and conditions of lithium batteries significantly impact their capacity. Temperature is undoubtedly one of the key factors affecting lithium battery lifespan. Excessively high or low temperatures reduce the content of active lithium ions, damage the structure of electrode materials, and cause metal ion dissolution, leading to severe capacity degradation. Conventional lithium batteries operate within a temperature range of -20°C to 60°C. Generally, performance declines below 0°C, and discharge capacity decreases accordingly. Therefore, the optimal operating temperature for lithium batteries is typically 0°C to 40°C. Lithium batteries designed for special environments may have different temperature requirements, with some even capable of normal operation at temperatures exceeding 100°C. 3. The primary factors affecting lithium battery capacity degradation include structural damage or deactivation of cathode and anode materials, electrolyte decomposition, and battery abuse. The charging and discharging process of a battery is a complex electrochemical process, and the factors leading to capacity degradation are not singular. Additionally, deterioration in one aspect may trigger other factors that collectively impact the battery's capacity, cycle performance, and energy density.

[DiRyan]

I have personally experienced lithium battery degradation from my own driving. The main reasons are daily usage habits, such as frequently letting the battery level drop too low before charging, or often using fast charging, which causes significant damage to the battery's internal materials. Temperature also plays a big role—parking the car under the scorching sun in summer or leaving it out in freezing temperatures overnight in winter can harm the battery's chemical performance. Additionally, as usage years increase, natural aging occurs, much like with smartphone batteries. I make sure to charge before the battery drops below 20% and reserve fast charging for emergencies only. I also try to park in underground garages and perform slow charging twice a month to balance the cells. After five years, my battery health is still at 85%. Taking care of your car requires attention to detail.

[SanJason]

Why do lithium batteries degrade? From an internal structural perspective, each charge and discharge cycle subtly alters the battery's material structure. Charging too quickly forces lithium ions to rapidly embed into electrode materials, increasing internal pressure and damaging the crystal lattice. Deep discharging to zero is even more hazardous, as it can cause electrolyte decomposition, depositing on electrode terminals to form passivation films that impair reaction efficiency. These chemical changes accelerate at high temperatures. Long-term storage at full charge may also promote internal dendrite growth. To extend battery life, it's recommended to maintain charge levels between 30%-80%, avoid charging in environments above 35°C, and store batteries at 50% charge. Periodic slow charging helps the battery management system recalibrate cell balance.

[DeAlice]

As an environmental advocate, concerns about battery degradation go beyond technical issues. Excessive degradation shortens battery lifespan, and discarded old batteries can cause heavy metal pollution and resource waste. In daily life, we should learn to slow down degradation—for example, avoid driving electric vehicles until they are completely out of power before charging, as that is devastating to electrode materials. Parking in the shade on hot days helps protect electrolyte stability. Using the original manufacturer’s adapter for charging is safer than third-party options. It’s recommended to charge as needed rather than performing deep charge-discharge cycles. Check the battery’s cycle count and health value quarterly. These habits extend battery life, thereby reducing the burden of pollution on the planet.

[McVincent]

I drive an electric vehicle for ride-hailing over eight hours daily, covering 80,000 kilometers a year. Deep charge and discharge occur every day, and fast charging is used almost three times daily, causing noticeably faster battery degradation compared to private vehicles. The key factor is the high-intensity usage leading to soaring temperatures, as the battery operating continuously above 45°C accelerates electrolyte decomposition. Later, I adjusted my charging strategy—avoiding charging during the midday heat and switching to fast charging in the evening when temperatures drop. I set the charging limit to 90% each time and waited 20 minutes after using a DC charger for cooling before driving. After sticking to this routine for half a year, tests showed the degradation rate slowed by 30%.

[StCarlos]

To address lithium battery degradation, focus on key points. Maintaining a mid-range charge level is safest – unplug at 80% and recharge at 20% to avoid extreme ranges. Avoid extreme temperatures; park in shade above 35°C and charge indoors below -10°C in winter. Charging methods matter: limit fast charging to 3 times weekly, using slow charging otherwise to balance voltage. Driving habits count – minimize sudden acceleration to reduce instant battery load. Use specialized testers monthly to monitor battery health, focusing on voltage difference and internal resistance changes. Consistently applying these methods can save half the cost of a new battery over five years.