Types and characteristics of lithium batteries

The performance differences of lithium batteries are largely due to the selection of positive electrode materials, and their different chemical compositions give them unique advantages and limitations. At present, the most widely commercialized types of lithium batteries can be mainly divided into the following five categories based on positive electrode materials:

1、 Lithium cobalt oxide battery (LiCoO ₂)

As the earliest commercialized lithium battery, lithium cobalt oxide battery has long dominated the consumer electronics market with an energy density of 140-160Wh/kg and a stable operating voltage of 3.7V. The demand for lightweight devices such as mobile phones and laptops made it an ideal choice in the early days - it can store more electricity in a limited volume, and the discharge curve is smooth, without causing device performance fluctuations due to changes in electricity. ​

But the shortcomings of this type of battery are also significant: cobalt content in the earth's crust is only 0.001%, and it is mainly produced in regions such as the Democratic Republic of Congo. The scarcity of resources has pushed up costs (cobalt prices account for more than 40% of battery material costs). More importantly, safety is crucial. When the temperature exceeds 150 ℃, the crystal structure of lithium cobalt oxide is prone to collapse, releasing oxygen and causing thermal runaway. In the event of overcharging, there is a higher risk of explosion. At present, its application has gradually been replaced by ternary batteries, only retaining a place in high-end small electronic devices. ​

2、 Lithium manganese oxide battery (LiMn ₂ O ₄)

The rise of lithium manganese oxide batteries is due to the low-cost advantage of manganese element (with a crustal content of 0.1%), and its manufacturing cost is about 30% lower than that of lithium cobalt oxide batteries. The working voltage of this type of battery is also maintained at around 3.7V, and its high-temperature stability is better than that of lithium cobalt oxide. Its structure is relatively stable below 200 ℃, making it suitable for cost sensitive scenarios such as electric bicycles and low-speed electric vehicles. ​

However, the problem of manganese dissolution is its fatal flaw: during charge and discharge cycles, manganese ions will detach from the positive electrode and enter the electrolyte, causing the battery capacity to decay at a rate of 5% -10% per month, and the cycle life is usually only 200-300 times. To improve this defect, manufacturers often use nickel and cobalt doping to form composite cathodes, but this may sacrifice some cost advantages. At present, lithium manganese oxide batteries are mostly used as auxiliary batteries in combination with other types of batteries. ​

3、 Three element lithium battery (NCM/NCA)

Ternary lithium batteries are "masters of performance balance", achieving complementary advantages through the synergistic effect of nickel, cobalt, manganese (or aluminum):

High nickel NCM (such as NCM811): After the nickel content is increased to 80%, the energy density exceeds 250Wh/kg, which can easily extend the range of electric vehicles beyond 600 kilometers. However, even with a cobalt content of 10%, resource limitations cannot be completely overcome; ​

NCA battery: The energy density of the nickel cobalt aluminum combination is higher (up to 300Wh/kg), making it the preferred choice for Tesla Model S. However, the aluminum element can easily lead to unstable material structure, requiring more complex process control. ​

The cycle life of this type of battery is about 1000-1500 times, and it has excellent low-temperature performance (with a capacity retention rate of over 70% at -20 ℃). However, the catalytic effect of nickel element at high temperatures will accelerate the decomposition of electrolyte, requiring a more precise thermal management system to be installed. At present, ternary lithium batteries have become the mainstream choice for mid to high end electric vehicles and have also begun to emerge in the field of energy storage. ​

4、 Lithium iron phosphate battery (LiFePO ₄)

Lithium iron phosphate batteries are synonymous with safety and longevity. Their olivine structure can remain stable at high temperatures of 800 ℃ and will not ignite or explode during extreme tests such as needle punching and squeezing. The cycle life can reach 3000-5000 times, and calculated based on daily charging and discharging, the service life can exceed 10 years, significantly reducing the overall life cycle cost. ​

But the energy density (100-160Wh/kg) is its obvious weakness, and the battery life is about 20% shorter than that of ternary batteries under the same weight. However, this deficiency is being compensated for by structural innovations such as CTP (no module). BYD blade batteries, with their long cell design, increase volume utilization by 50% while maintaining the safety genes of lithium iron phosphate. At present, it is widely used in scenarios with extremely high safety requirements such as buses and energy storage stations, and its market share in the mid to low end electric vehicle market is also rapidly expanding. ​

5、 Lithium titanate battery (Li ₄ Ti ₅ O ₁₂)

Lithium titanate batteries are a unique anomaly, with their innovation in the negative electrode - replacing traditional graphite with lithium titanate to make the lithium ion insertion process more stable. This brings three major advantages:

Ultra fast charging capability: can charge up to 80% of battery in 10 minutes, suitable for scenarios such as buses and taxis that require rapid energy replenishment; ​

Ultra long lifespan: With over 20000 cycles, it is more than 10 times longer than ordinary lithium batteries; ​

Wide temperature adaptability: It can still work normally in environments ranging from -50 ℃ to 60 ℃, and performs outstandingly in extremely cold regions. ​

However, the energy density of 30-80Wh/kg and the high cost (three times that of lithium iron phosphate batteries) limit its application, and it is currently only used in niche fields such as energy storage frequency regulation and military equipment. However, with the development of solid-state electrolyte technology, lithium titanate is expected to find a new position in the next generation of fast charging batteries. ​

Different types of lithium batteries are like athletes with different strengths, there is no absolute superiority or inferiority, only differences in whether they are suitable for specific scenarios. Understanding their characteristics not only helps us better choose electronic devices, but also enables us to see the technological evolution path of the new energy industry - from pursuing energy density to balancing safety and cost. The development of lithium batteries has always revolved around humanity's eternal demand for efficient and safe energy storage.