What are the disadvantages of lithium iron phosphate?

Japan and South Korea mainly develop modification nickel cobalt manganese acid lithium, manganese acid lithium and power lithium ion batteries that use ternary material as anode material in recent years. Toyota and Panasonic EV Energy joint venture company, Hitachi, SONY, Shin-kobe Electric Machinery, NEC, Sanyo, Samsung, LG, etc.

The main development of the anode materials for lithium iron phosphate power type lithium ion battery, such as A123 systems, Valence, but the major automobile manufacturers in the PHEV and EV is the choice of manganese base power type lithium ion battery cathode material system, and it is said that the A123 company in the field of consideration into manganese acid lithium materials, and Germany and other European countries mainly adopt the battery company cooperation with other countries to develop electric vehicles, such as Daimler and French saft alliance, Volkswagen of Germany and Japan Sanyo cooperation agreement, etc. Currently Volkswagen of Germany and France's Renault sa with the support of their governments are development and production of power type lithium ion battery.

Disadvantages

Is a kind of material has great potential application development, in addition to focus on its merits, even more crucial is whether the material has fundamental flaws.

Domestic now generally choose the lithium iron phosphate as power type lithium ion battery cathode material, from the government, scientific research institutions, enterprises, and even markets such as securities analysts are bullish on this material, as the development direction of power type lithium ion battery.

Analysis its reason, mainly has the following two points: first is influenced by American research direction, the Valence and the A123 company do early adoption of lithium iron phosphate lithium ion battery cathode material. Followed by the domestic has not been prepared for use with power type lithium ion battery has good high temperature cycle and storage performance of manganese acid lithium materials. But there are also nots allow to ignore the fundamental flaws of lithium iron phosphate, it mainly include the following:

1. During the preparation of lithium iron phosphate sintering process, the reduction of iron oxide under high temperature and reducing atmosphere is the possibility of elemental iron. Elemental iron can cause cell micro short circuit, is the most taboo in the battery material. This is Japan has not the material as the main reason of power type lithium ion battery cathode material;

2. Lithium iron phosphate has some defects on the performance, such as low tap density and compaction density, leading to a lower energy density of lithium-ion batteries. Low temperature performance is poorer, even if the nano and carbon coating to solve this problem. Argonne national laboratory, Dr DonHillebrand, director of the center for energy storage system when it comes to the lithium iron phosphate battery performance at low temperature with terrible to describe, they type of lithium iron phosphate lithium-ion battery test results show that indicate lithium iron phosphate batteries at low temperature (below 0 ℃) could not make the electric car. Although there is also a manufacturer claims that the lithium iron phosphate battery capacity in low temperature retention is good, but it's a small discharge current and discharge cut-off voltage is very low. Under this condition, the equipment can't start the job.

3. The preparation of material cost and manufacturing cost is higher, batteries battery low yield, poor consistency. Lithium iron phosphate nano and carbon coated despite the electrochemical properties of the material, but also brought other problems, such as lower energy density and the rising cost of synthesis, electrode processing performance is poor and demanding to the environment and other problems. Despite the lithium iron phosphate chemical elements in the Li, Fe and P is very rich, and a low cost, but could be prepared for the lithium iron phosphate product cost is not low, even with previous research and development costs, the process of the material cost and high cost of batteries, will make the final unit cost of energy storage battery is higher.

4. Product consistency. At present domestic has not been a lithium iron phosphate material factory can solve this problem. From the Angle of material preparation, the synthetic reaction of the lithium iron phosphate is a complex multiphase reaction, has a solid phosphate, iron oxide and lithium salt, plus the precursor and carbon reduction aerosols. In the process of the complex reaction, it is difficult to ensure consistency of response.

5. The problem of intellectual property rights. The earliest on an application for a patent for the lithium iron phosphate in June 25, 1993 by FXMITTERMAIER&SOEHNEOHG (DE), and in the same year on August 19, the application results. The basis of the lithium iron phosphate all patents by the United States at the university of Texas, and carbon coated by Canadian patent application. The two basic patent is not around the past, if royalties on the cost of calculation, the product cost will be further improved.

In addition, from the perspective of the experience of development and production of lithium ion battery, Japan is the country of the first commercial lithium-ion batteries, and high-end lithium ion battery has dominated the market. Although in some basic research on the leading and the United States, but so far there is no single large lithium-ion battery production enterprises. As a result, Japan chose as power type lithium manganese acid lithium ion battery cathode material more makes sense. Even in the United States, use and lithium manganese acid lithium iron phosphate as the manufacturer of power type lithium ion battery cathode material is also a half, the federal government is also support for the development of the two systems.

In view of the problems existing in the lithium iron phosphate, difficult as power type lithium ion battery cathode material in the field of new energy vehicles for a wide range of applications. If you can solve the manganese acid lithium storage high temperature cycle and difficult problems of poor performance, with its advantage of low cost and high performance ratio in the application of power type lithium ion battery will have great potential.

6. Working principle and characteristics of lithium iron phosphate battery full name is lithium ion battery, lithium iron phosphate the name was too long, referred to as lithium iron phosphate batteries. Because of its performance is particularly suitable for power applications, to join in the name of "power" two words, namely lithium iron phosphate power battery. Also some people called it "lithium iron (LiFe)Power battery".

The page contains the contents of the machine translation.