In the context of carbon peaking and carbon neutrality, my country's energy structure is in a critical period of transition from fossil energy to new energy sources such as wind, light, and hydrogen. Fluorine materials are also playing an increasingly important role in the new energy industry due to their special properties. Important role, let’s take a look at which fluorine materials can be used in the new energy industry!
1.Lithium hexafluorophosphate
Lithium hexafluorophosphate, currently the most mainstream electrolyte material, accounts for a relatively high cost in the electrolyte, and its price is highly correlated with the price of the electrolyte. Since the second half of 2020, the rapid increase in sales of new energy vehicles has led to an explosion in demand for lithium batteries. Lithium hexafluorophosphate, as the soul material of the electrolyte, has also ushered in a period of explosive demand. Domestic companies have expanded production one after another, and the supply and demand relationship has also rapidly changed, and is currently in a downturn. Expect.
2. PVDF
In lithium batteries, PVDF is mainly used as cathode binder and can also be used for separators and separator coatings. PVDF is an oil-soluble binder that connects electrode active materials, conductive agents and electrode current collectors to each other and plays a variety of roles. Although the amount of PVDF binder added is small, it directly affects the battery's cycle performance, rapid charge and discharge capabilities, and battery internal resistance. Like lithium hexafluorophosphate, PVDF has also experienced ups and downs, and new entrants are currently more cautious. In the solar field, PVDF is mainly used as photovoltaic backsheet film. The backsheet supports and protects the cells, and as a packaging material that is directly in contact with the external natural environment over a large area, its performance directly determines the power generation efficiency and service life of the photovoltaic module. The backsheet must have excellent insulation, For properties such as water vapor barrier and weather resistance, material selection is particularly important.
PVDF has good mechanical strength, chemical stability, electrochemical stability and thermal stability. The photovoltaic backsheet film made of it can well protect the photovoltaic modules from the influence of the external environment and extend their service life. It is currently the One of the most widely used backsheet films.
3.PVF
As a fluorine-containing polymer material, PVF also has many excellent properties and is a fluorine film material widely used in photovoltaic backsheets. Compared with PVDF, PVF contains lower fluorine, its UV resistance and chemical resistance are not as good as PVDF, its density is worse than PVDF, and its sand resistance is also weaker than PVDF. In recent years, its market share in photovoltaics has been gradually replaced by PVDF. PVDF It has also become the largest fluorine membrane material in the market.
4.LiTFSI
Lithium bis(trifluoromethanesulfonyl)imide, LiTFSI , is added to the electrolyte in proportion to lithium hexafluorophosphate, which can effectively improve the service life and safety performance of the battery. It has the characteristics of higher conductivity, resistance to hydrolysis, and thermal stability. Therefore, LiTFSI can become an additive to improve the defects of lithium hexafluorophosphate, which is in line with the development trend of the new energy automobile industry.
With the rapid expansion of global demand for lithium-ion batteries, the accelerated growth of electrolyte production and sales will drive the use of LiTFSI to increase year by year, and the market prospects are very broad.
At present, domestic lithium bis(trifluoromethanesulfonyl)imide is mainly concentrated in Parite Gas and Jiangsu Cathay Chaowei New Materials, while foreign competitive companies are mainly Solvay.
In addition, LiTFSI can also be used in polymer solid-state battery electrolytes. LiTFSI has high ionic conductivity and is widely used as a single conductive lithium salt in polymer electrolytes. With the gradual industrialization of solid-state batteries, LiTFSI will usher in new growth points.
At present, many domestic companies are deploying LiTFSI, such as Duofuoduo, Limin Co., Ltd., Zhongxin Fluoro Materials, CSSC Special Gas, etc. Among them, CSSC Special Gas has achieved mass production of LiTFSI, Limin Co., Ltd., Zhongxin Co., Ltd. LiTFSI of companies such as fluorine materials is still in the small-scale trial stage, and Duofuoduo already has LiTFSI production technology.
5.LiFSI
LiFSI : Although lithium hexafluorophosphate is the mainstream electrolyte lithium salt, its properties are unstable and will decompose rapidly when exposed to the air. It will begin to decompose at slightly higher temperatures. Therefore, it is required to avoid high temperature and high humidity environments for storage.
Compared with lithium hexafluorophosphate, LiFSI has high stability, does not decompose below 200°C, has excellent low-temperature performance, and has good hydrolysis stability. It exceeds lithium hexafluorophosphate in performance indicators such as conductivity, lithium evolution reaction, and thermal stability, and is expected to replace lithium hexafluorophosphate as an electrolyte material.
LiFSI is mainly used as an electrolyte lithium salt in two ways: first, it is used as an additive for lithium hexafluorophosphate, and the dosage is generally 0% to 3%; second, it is used as a new lithium salt to partially replace lithium hexafluorophosphate, and the dosage is 3% to 5%. The dosage in silicon carbon anode system is higher. Currently, the lithium salts on the market are mainly lithium hexafluorophosphate. LiFSI is mostly used in ternary lithium batteries, and is often used as an auxiliary additive in lithium batteries.
In the future, with the continuous development of lithium battery technology, the increasingly mature LiFSI production process, the gradual decrease of production costs and the trend of high nickel content in ternary power batteries, the usage of LiFSI is expected to increase rapidly.
FEC: The chemical name of FEC is 4-fluoro-1,3-dioxolane-2-one, commonly known as fluorinated ethylene carbonate. It is one of the most widely used fluorine-containing additives. FEC will be used in the negative electrode. A layer of SEI film with tight structure and excellent performance is formed on the surface, which reduces the battery impedance while improving the low-temperature performance of the electrolyte, thereby increasing the battery specific capacity and improving the cycle stability of the battery, especially the cycle stability of Si-containing lithium-ion batteries.
Benefiting from the development of consumer electronics, new energy vehicles and other industries, lithium battery electrolyte shipments are showing a growth trend, and FEC demand is also growing steadily. In addition, FEC can also be used in sodium-ion batteries. At present, the country has introduced many policies to support the development of energy storage. The energy storage industry is expected to develop rapidly. The sodium-ion battery market will expand rapidly, which will drive a substantial increase in FEC demand.
Let’s do it!
6. Perfluorosulfonic acid resin/membrane
The proton exchange membrane is the core component of the proton exchange membrane fuel cell. During the battery operation, it plays the role of providing hydrogen ion channels and isolating the cathode and anode reactants. Its performance directly affects the performance, energy conversion efficiency and service life, etc.
Currently, perfluorosulfonic acid-type proton exchange membranes are widely used in the industry, which are prepared from perfluorosulfonic acid resin through film formation. The main chain of the perfluorosulfonic acid resin (PFSA) molecule has a polytetrafluoroethylene (PTFE) structure. The fluorine atoms in the molecule can tightly cover the carbon-carbon chain, and the carbon-fluorine bond has a short length, high bond energy, and is extremely The low chemical degree makes the molecule have excellent thermal stability, chemical stability and high mechanical strength; the hydrophilic sulfonic acid group on the branch chain of the molecule can adsorb water molecules and has excellent ion conductivity characteristics.
Perfluorosulfonic acid proton exchange membrane has obvious advantages in terms of structure and performance. It has the advantages of high chemical stability, high proton conductivity, high mechanical strength, high current density at low temperature and low proton conduction resistance. It can meet the needs of today's Stage PEMFC usage requirements.
7. Electronic grade hydrofluoric acid
Electronic-grade hydrofluoric acid is mainly used to remove oxides. It is one of the most commonly used electronic chemicals in the semiconductor manufacturing process and is widely used in integrated circuits, solar photovoltaics, liquid crystal displays and other fields. In the field of photovoltaics, electronic hydrofluoric acid is mainly used in process engineering such as texturing and cleaning of solar cells, accounting for about 25% of the total consumption of electronic grade hydrofluoric acid.
With the rapid development of the photovoltaic industry, the demand for photovoltaic grade electronic hydrofluoric acid is also increasing. Data shows that domestic photovoltaic cell production in 2023 will be about 540GW, consuming about 480,000 tons of electronic-grade hydrofluoric acid. However, because the electronic grade hydrofluoric acid required in the photovoltaic cell field is concentrated in the G1 grade, there is already overcapacity and it has fallen into serious homogeneous competition.
summary
In fact, in addition to the fluorine materials mentioned above, there are many fluorine materials that can be used in the new energy industry, such as lithium difluorophosphate, THV, ETFE, etc. Whether in lithium batteries, photovoltaics or other new energy sources, fluorine materials play a pivotal role. The development and use of fluorine materials are of great significance to reducing costs and the eventual large-scale promotion and application of new energy sources.