An article to understand the lithium phosphate battery

Unveiling the mystery of lithium phosphate batteries

So what exactly is a lithium phosphate battery? As the name suggests, it is closely related to the material lithium iron phosphate. Simply put, a lithium phosphate battery is a lithium-ion battery that uses lithium iron phosphate as the positive electrode material. Just like building blocks, in this type of battery, lithium iron phosphate is an important “building block” and plays a key role.

Lithium iron phosphate is a material with the chemical formula LiFePO₄, which is composed of lithium (Li), iron (Fe), phosphorus (P), and oxygen (O). Don’t underestimate these elements. When combined together, lithium iron phosphate has a unique “personality”. It has an olivine structure, just like a stable little house. This structure gives lithium iron phosphate good thermal stability. It can remain stable in high temperature environments and will not easily “lose its temper”. Moreover, lithium iron phosphate is relatively low in cost and relatively abundant in resources, unlike some materials, which are expensive and difficult to find. At the same time, it is also very environmentally friendly and will not cause too much burden on the environment. It has many advantages.

From birth to rise: the development history of lithium phosphate batteries

The birth and development of lithium phosphate batteries is a journey full of innovation and challenges. In 1997, the team led by Goodenough at the University of Texas proposed the concept of lithium phosphate batteries, which was like planting a seed of hope in the energy field. At that time, researchers found that lithium iron phosphate performed well in the charging and discharging process. Although its performance was not perfect at that time, it had already shown great potential and attracted the attention of many people.

In 2004, the US A123 Company and Shenzhen BAK Battery Co., Ltd. jointly developed the world’s first lithium iron phosphate power battery and achieved industrialization, and lithium phosphate batteries officially entered the market. This is like a child growing up and starting to play a role in society. Subsequently, its application areas continued to expand. In 2009, lithium phosphate batteries were used in the field of energy storage, playing a more important role in the development of new energy, and providing new solutions for the storage and rational use of energy.

From 2014 to 2016, China vigorously promoted the development of new energy vehicles, and lithium phosphate batteries ushered in opportunities, but also faced challenges. As the country’s assessment standards for the energy density of new energy vehicle power batteries have been improved, the development of lithium phosphate batteries has been hindered because of their lower energy density than ternary lithium batteries. Many related companies have even gone bankrupt, and lithium phosphate batteries seem to have fallen into a “cold winter.”

However, researchers did not give up and have been working hard to overcome technical difficulties. After 2019, CATL launched CTP technology, BYD launched blade batteries, and Guoxuan High-tech launched JTM technology. These integrated manufacturing technology innovations effectively made up for the shortcomings of low energy density of lithium phosphate batteries. Coupled with the decline in China’s new energy vehicle purchase subsidies year by year, lower-cost lithium phosphate batteries have ushered in a new “spring” of development. In May 2021, its power battery production exceeded that of ternary material batteries. Today, lithium phosphate batteries are widely used in new energy vehicles, energy storage and other fields, and their development prospects are bright.

How it works: How energy flows

Now that we know the basic composition of lithium phosphate batteries, how do they work? In fact, the working process of lithium phosphate batteries is a process of lithium ions “moving” back and forth between the positive and negative electrodes.

When charging, lithium ions are like a group of hardworking little ants, “running” out of the lithium iron phosphate cathode material, passing through the “highway” of the electrolyte, and reaching the graphite cathode, and embedding into the layered structure of graphite. At this time, the battery is storing energy, converting electrical energy into chemical energy and storing it. It’s like you put your pocket money in a piggy bank and take it out when you need it.

When discharging, the process is reversed. Lithium ions are “deintercalated” from the graphite negative electrode and then return to the lithium iron phosphate positive electrode along the “highway” of the electrolyte. In this process, chemical energy is converted into electrical energy to power our devices, just like taking pocket money out of a piggy bank to buy things.

In this charging and discharging process, the diaphragm and electrolyte also play a key role. The diaphragm is like an “isolation guard” that separates the positive and negative electrodes to prevent them from directly contacting and short-circuiting, but allows lithium ions to pass through to ensure the normal operation of the battery. The electrolyte is like a “courier” responsible for transporting lithium ions between the positive and negative electrodes, allowing lithium ions to move smoothly between the positive and negative electrodes to complete charging and discharging.

Advantages revealed: Why did he debut in the C position?

Lithium phosphate batteries can stand out among many lithium batteries, so they must have some “brushes”. Next, I will tell you about its advantages in detail.

High security: a reassuring “safety guard”

Among the various performance characteristics of batteries, safety is absolutely the top priority. Lithium phosphate batteries perform well in this regard and can be called “safety guards.” Its positive electrode material, lithium iron phosphate, has super stability of PO bonds in the crystal structure, just like a solid city wall. Even if it encounters “enemies” such as high temperature and overcharging, it is not easy to decompose. It will not produce strong oxidizing substances like some batteries, leading to dangers such as combustion and explosion. For example, there have been news reports that some new energy vehicles using other types of lithium batteries are prone to fire and explosion when they collide or charge abnormally, while cars equipped with lithium phosphate batteries have a much lower probability of serious accidents under similar circumstances. Just like BYD’s “blade battery”, which is essentially a lithium phosphate battery, it has undergone rigorous tests such as needle puncture tests. During the needle puncture process, the battery did not catch fire or explode, but the surface temperature increased slightly, fully demonstrating the high safety of lithium phosphate batteries.

Long cycle life: a long-lasting and durable long-distance runner

Cycle life is an important indicator to measure the quality of a battery. Simply put, it refers to how many complete charge and discharge cycles a battery can go through. Lithium phosphate batteries are like “long-distance runners” with a very long cycle life, usually more than 2,000 times, and even 5,000 times for good quality ones. In comparison, the cycle life of lead-acid batteries is generally only about 300 times, and the gap is very obvious. This means that when using lithium phosphate batteries, there is no need to replace batteries frequently, which saves money and worry. For example, in the field of energy storage, an energy storage system using lithium phosphate batteries can operate stably for many years and perform a large number of charge and discharge cycles, providing reliable guarantees for energy storage and deployment, and greatly reducing subsequent maintenance and replacement costs.

Good environmental protection: “Green Messenger” to protect the environment

Today, as environmental awareness is increasing, the environmental friendliness of batteries has also attracted much attention. Lithium phosphate batteries can be said to be the “green messenger” that protects the environment. Its main components are iron and phosphorus, which are not only abundant in resources but also very environmentally friendly. During the production process, it does not produce a large amount of heavy metal pollution like some traditional batteries. Moreover, lithium phosphate batteries are relatively easy to recycle, which can effectively reduce the harm of battery waste to the environment and is in line with the concept of sustainable development. BYD has made a lot of efforts in battery recycling, recycling used lithium phosphate batteries , extracting useful materials from them, and re-putting them into production, which not only saves resources but also protects the environment.

Fast charging speed: efficient and convenient “fast charging expert”

In this fast-paced era, charging speed is also a matter of concern to everyone. Lithium phosphate batteries perform well in this regard and are “fast charging experts”. They have high charging efficiency and can be charged in a short time. For example, some new energy vehicles equipped with lithium phosphate batteries can charge the power from a low level to about 80% in about half an hour when using fast charging equipment, which greatly saves charging time. For those who need to travel frequently, this is very convenient. They don’t have to wait for a long time to charge, and can arrange their trips more efficiently.

Stable performance: a versatile tool for various environments

Regardless of the temperature and working conditions, the performance of lithium phosphate batteries is relatively stable, just like an “all-rounder” with super adaptability. In a high temperature environment, it can maintain a low internal resistance and a high cycle life, and will not “break down” due to the increase in temperature, and can still output electrical energy stably. In a low temperature environment, although its performance will be affected to a certain extent, it is already a good performance compared to some other types of batteries. For example, in the cold winter, the battery of some mobile phones will drop rapidly due to low temperatures, or even shut down automatically, but the probability of this happening to devices using lithium phosphate batteries will be much smaller, and they can still work normally and meet our needs.

Disadvantages: No battery is perfect

Although lithium phosphate batteries have many advantages, there is no perfect battery in the world, and it also has some shortcomings.

Low energy density: slightly “bulky” energy carrier

Compared with ternary lithium batteries, lithium phosphate batteries have a lower energy density. Low energy density means that it does not store as much electrical energy at the same weight or volume. For example, the energy density of ternary lithium batteries can reach more than 200Wh/kg, while lithium phosphate batteries are generally around 150Wh/kg. This is like two backpacks, one can hold a lot of things, and the other can hold less. Therefore, devices using lithium phosphate batteries may have a shorter range, or in order to achieve a certain range, a larger battery size and weight are required, which will be limited in some application scenarios that have strict requirements on space and weight, such as drones.

High cost: price factors restricting popularization

Although the material itself is not expensive and the resources are abundant, the overall manufacturing cost of lithium phosphate batteries is not low. On the one hand, its production process is relatively complicated and has high requirements for production equipment and environment, which increases the production cost. On the other hand, the production efficiency of lithium phosphate batteries is not high enough, and the yield rate needs to be improved, which will make it difficult to reduce the final battery cost. Compared with some other types of batteries, the price advantage of lithium phosphate batteries is not so obvious, which to a certain extent limits its application and popularity in a wider range of fields.

Poor low temperature performance: a cold weather annoyance

Lithium phosphate batteries do not perform well in low temperature environments, which can be said to be a “small shortcoming”. When the temperature is below 0℃, its performance will be significantly affected, the internal resistance of the battery will increase, resulting in a decrease in battery capacity and a slower charging speed. At around -20℃, the battery capacity decay may reach about 55%. This is like in winter, people’s mobility will weaken, and the battery will be “less powerful” at low temperatures. In the cold winter in the north, the range of electric vehicles using lithium phosphate batteries will be greatly shortened, causing a lot of trouble for users.

The problem of consistency: uneven “team members”

When producing lithium phosphate batteries, it is not easy to ensure that the performance of each battery is completely consistent. Due to the influence of factors such as production process and raw materials, there will be certain differences between different batteries, which is the consistency problem. When multiple batteries are used in a battery pack, this inconsistency will be highlighted. Just like in a team, if the abilities of members are uneven, the overall work efficiency will be affected. Batteries with poor performance in the battery pack will limit the performance of the entire battery pack, resulting in a shortened cycle life of the battery pack, and may also affect the stability and reliability of the equipment.

However, researchers have not been idle and have been working hard to overcome these problems. By improving material formulas, optimizing production processes, and developing new battery structures, the performance of lithium phosphate batteries has been improved, and its shortcomings have been gradually improved.

Widely used: “invisible assistant” in life

Lithium phosphate batteries have been widely used in many fields due to their own advantages. They are like “invisible assistants” in our lives, playing an important role silently.

Electric vehicle sector: making travel greener and safer

In the field of electric vehicles, lithium phosphate batteries are “star products”. Tesla has many models that use lithium phosphate batteries, and BYD’s “blade battery” is also a type of lithium phosphate battery. These electric vehicles equipped with lithium phosphate batteries have guaranteed safety, long cycle life, and relatively low cost. For example, the Tesla Model 3 Standard Range Upgrade Edition, after replacing the lithium phosphate battery, has a higher cost-effectiveness, allowing more consumers to enjoy the convenience and environmental protection brought by electric vehicles. Moreover, with the advancement of technology, the energy density of lithium phosphate batteries continues to increase, and the cruising range is also increasing. In the future, it is expected to meet the travel needs of more consumers and make electric vehicles more competitive in the market.

Energy storage system field: the “stable steward” of energy

In the field of energy storage systems, lithium phosphate batteries also perform well. It is like a “stable housekeeper” that can store excess electrical energy and release it when needed, providing a guarantee for a stable supply of energy. Whether it is the safe grid connection of renewable energy power generation such as wind power generation and photovoltaic power generation, or grid peak regulation and distributed power stations, lithium phosphate battery energy storage systems are indispensable. In some remote areas, the electricity generated by photovoltaic power generation can be stored in lithium phosphate batteries for local residents to use at night or on cloudy days, solving the problem of unstable energy supply. Moreover, the long cycle life and high safety of lithium phosphate batteries also make the energy storage system more reliable and able to operate stably for a long time.

Power tools: a powerful partner for efficient work

In the field of power tools, lithium phosphate batteries have become a “powerful partner” for many people. For common power tools such as electric drills and electric saws, the charging speed is faster after using lithium phosphate batteries, which allows us to complete the work more efficiently. Moreover, the high safety of lithium phosphate batteries also reduces the safety risks when using power tools. For example, some professional construction workers use power tools equipped with lithium phosphate batteries without worrying about the battery being dangerous during use, and they can work more safely.

Portable electronic devices: small size, big power

In the field of portable electronic devices, although the energy density of lithium phosphate batteries is not the highest, its stability and safety allow it to be used in some devices that have special requirements for battery performance. Field detection instruments, military communication equipment, etc. require batteries to work stably in different environments, and lithium phosphate batteries meet these requirements well. When exploring the wild, if the handheld GPS device uses lithium phosphate batteries, it can ensure the normal operation of the equipment even in harsh environments such as high and low temperatures, and provide accurate positioning information for explorers.

The future is promising: development trend outlook

Looking ahead, the development prospects of lithium phosphate batteries are bright, and major breakthroughs are expected in many key areas.

In terms of cost control, with the maturity of technology and the improvement of the industrial chain, there is a lot of room for reduction in raw material costs and production costs. Authoritative research institutions predict that by 2025, the cost of lithium iron phosphate is expected to drop to 0.4 yuan/Wh, a 60% decrease from 2020. The reduction in costs will make lithium phosphate batteries more price competitive in the market and further promote their popularity in various fields.

Improving energy density is also a key direction for the future development of lithium phosphate batteries. Researchers are actively developing new materials and processes to improve the energy density of lithium phosphate batteries . Companies such as CATL have achieved some results in this regard and are expected to achieve greater breakthroughs in the future. It is expected that in the next few years, the energy density of lithium phosphate batteries may increase to more than 200Wh/kg, effectively solving the problem of short driving range.

The progress of recycling technology has also attracted much attention. At present, the recycling of waste lithium iron phosphate batteries has become a hot spot in the industry. With the continuous advancement of technology, the recycling efficiency and resource utilization rate will be greatly improved. In the future, more environmentally friendly and efficient recycling technologies may emerge to achieve the recycling of battery materials and reduce the impact on the environment. At the same time, it can also reduce the mining of raw materials and save resources.

In terms of application expansion, in addition to the existing electric vehicles, energy storage, power tools and other fields, lithium phosphate batteries are expected to shine in more new fields. For example, in the aerospace field, as its energy density increases, it may be used in small aircraft in the future; in the field of smart homes, lithium phosphate batteries can also provide stable power support for various smart devices, opening up a broader market space.

Summary and Interaction

In general, lithium phosphate batteries play an important role in electric vehicles, energy storage systems, power tools, and portable electronic devices due to their high safety, long cycle life, good environmental protection, fast charging speed, and stable performance. Although it has shortcomings such as low energy density, high cost, poor low temperature performance, and consistency issues, these problems are gradually being solved with the continuous advancement of technology, and the future development prospects are very broad.

If you have any questions about lithium phosphate batteries, or have your own ideas about its future application scenarios, please leave a message in the comment area to discuss. Let’s boldly predict which new field lithium phosphate batteries will be widely used in five years? I look forward to everyone sharing their views, and we will communicate together to explore more possibilities of lithium phosphate batteries.