Analysis of the "Shortcomings" of Lithium Iron Phosphate Batteries

In the field of batteries, lithium iron phosphate batteries have once become a popular choice due to their many advantages. However, just like two sides of a coin, it also has some undeniable shortcomings.

1.Poor low-temperature performance

When in a low-temperature environment, the performance of lithium iron batteries is truly worrying. There are exact data showing that when the ambient temperature drops to -10°C, its capacity will attenuated by 40 – 50%. And when the temperature reaches -20°C, the battery may even completely lose its discharge capacity. The main reason behind this is that the positive electrode material, lithium iron phosphate, has relatively poor conductivity and is prone to polarization, which leads to capacity attenuation. At the same time, the viscosity of the internal electrolyte increases at low temperatures, the migration resistance of lithium ions increases, and the diffusion speed slows down, greatly reducing the activity of the battery. In addition, in a low-temperature environment, the SEI film on the negative electrode will also become thicker, the impedance will increase, and the conduction rate of lithium ions between the SEI films will significantly decrease. At present, in order to alleviate this problem, major automakers can only install battery temperature management systems and provide low-temperature heating functions to minimize the impact of capacity attenuation.

2.Low energy density

In the pursuit of high energy density, lithium iron batteries seem a bit powerless in this regard. When a certain energy density is reached, its battery volume and weight are relatively large. For example, when the energy density reaches 150wh/kg, its battery volume and weight will be more prominent. Under the same weight and volume, its capacity is relatively low. Compared with other types of batteries, its energy density is only 3 – 4 times that of lead-acid batteries, 2.5 times that of nickel-cadmium batteries, and 1.8 times that of nickel-metal hydride batteries. Compared with some high-performance batteries, the energy density of lithium iron batteries still has a lot of room for improvement.

3. Short battery pack life

Although the life of a single lithium iron phosphate battery is relatively long, reaching about 2000 cycles, the life of a battery pack is generally only about 500 cycles, which is significantly lower than that of a single battery. Compared with other batteries, lithium iron phosphate battery packs do not have obvious advantages in terms of life. In the second-hand market, we can see a large number of battery packs that are eliminated before reaching the expected life.

4.High production cost

The production cost of lithium iron batteries is relatively high, whether it is the material preparation cost or the battery manufacturing cost. Taking the common nickel-cobalt-manganese lithium battery as an example, the prices of nickel and cobalt in its main raw materials are relatively high, and these two materials are used very little or not at all in lithium iron batteries, but the overall cost of lithium iron batteries is not low. The procurement cost of raw materials plus the relatively high battery preparation cost makes the cost per unit of energy storage relatively high. In addition, there are also patent disputes over the production of lithium iron phosphate abroad, which undoubtedly further increases the cost.

5.Unstable process performance

Lithium iron phosphate batteries have problems of poor consistency. The life of the battery pack is significantly lower than that of a single battery, and the low-temperature performance is not good. When the temperature is lower than 0 degrees Celsius, the capacity drops rapidly, and the cycle performance is extremely poor at low temperatures. At the same time, the conductivity is poor, the diffusion speed of lithium ions is slow, and the actual specific capacity is low during high-rate charging and discharging. In the sintering process of lithium iron phosphate preparation, iron oxide has the possibility of being reduced to elemental iron in a high-temperature reducing atmosphere, and elemental iron can cause micro-shorts in the battery, which is the most taboo substance in batteries. In addition, although the nanonization and carbon coating of lithium iron phosphate improve the electrochemical performance of the material, they also bring other problems, such as reduced energy density, increased synthesis cost, poor electrode processing performance, and stringent environmental requirements.

Although lithium iron batteries have these shortcomings, they also have many advantages. First of all, lithium iron phosphate batteries have good safety. It has high stability in high-temperature environments and is not prone to dangerous situations such as combustion and explosion. Secondly, it has a long cycle life. A single battery can reach about 2000 cycles, which can meet the needs of most application scenarios. Moreover, lithium iron phosphate batteries are environmentally friendly and non-toxic, friendly to the environment.

Huijue lithium iron batteries also have a unique position in the industry. Huijue Company is committed to the research and development and production of lithium iron batteries, and continuously improves the performance and quality of products. Its lithium iron batteries adopt advanced production processes and technologies, and perform outstandingly in terms of safety and cycle life. Huijue pays attention to the stability and consistency of products. Through a strict quality control system, it ensures that each battery can reach a high-quality standard. At the same time, Huijue is also actively exploring methods to reduce costs to improve the market competitiveness of products. In the future, it is believed that Huijue lithium iron phosphate batteries will play a greater role in the field of new energy.

To sum up, although lithium iron batteries perform well in some aspects, these shortcomings also limit their application in some specific fields. In the future, with the continuous progress of technology, we look forward to these problems being effectively solved so that lithium iron phosphate batteries can exert greater potential.