Recently, a project named "National Key R&D Program 'New Energy Vehicle' Special 'Basic Frontier Research on New System Power Battery'" was successfully launched, led by Peking University and cooperated with Xiamen University, Beijing Institute of Technology, Nanjing University, Wuhan University, Tsinghua University and other domestic advantageous research units.
The project aims to improve battery energy density, thermal stability and safety by studying key technologies such as new electrode materials, electrolytes and separator materials, and the results of this research will provide important support for the development of new energy vehicles, and are expected to promote technological changes and upgrades in the field of power batteries in the future.
The latest progress in the research of battery materials for new energy vehicles
At present, the research of new energy vehicle battery materials is showing a state of rapid development, in recent years, with the continuous improvement of people's demand for environmental protection and new energy, the research and development of battery materials has become the focus of many scientific research institutions and enterprises.
In the field of lithium-ion batteries, in addition to traditional electrode materials such as lithium cobalt oxide and ternary materials, a number of new electrode materials have emerged in recent years, such as silicon-based materials, composite materials, micro/nano materials, etc.
These materials have shown great potential in improving battery energy storage, cycle performance and safety, and with the increasing requirements of pure electric vehicles for cruising range, the integration and optimization of battery systems have also become an important direction for battery material research.
All-solid-state battery as a potential advantage of battery technology, but also become one of the current battery material research hotspots, recently reported that the University of Science and Technology of China research team has made new progress in the field of lithium battery solid electrolyte, which may bring new breakthroughs to the research of all-solid-state lithium batteries.
In order to cope with the problems of battery temperature rise and expansion during high-speed charging of electric vehicles, the research of separator materials has also attracted increasing attention, and some new separator materials have become one of the research directions because of their excellent thermal stability, electrochemical stability and mechanical strength.
Rubber has high strength, high toughness, good crack resistance and wear resistance and other characteristics, can also withstand large deformation and repetitive stress, in high temperature environment easy aging, failure, but also there is oil resistance, solvent resistance and other problems, rubber is a linear flexible polymer, molecular chain flexibility is good, can produce a variety of complex shapes, so widely used in the manufacture of a variety of seals, sleeves, pipes and vibration isolators and other applications.
With the improvement of people's performance requirements for rubber products, the future research focus of rubber materials will be on the design and synthesis of new rubber, seeking better aging resistance, wear resistance and high temperature resistance.
Fiber materials have excellent tensile strength and modulus, while light weight, good flame retardancy, air, water, food, etc. have a good protective effect, relatively fragile, easy to mechanical damage and chemical erosion, fiber materials involve many fields, such as textiles, aerospace, medical, etc., in addition to high-performance fiber materials also have excellent elasticity, sound absorption, heat insulation performance.
Therefore, it is also widely used in construction, automobiles, clothing, etc., and the future research direction of fiber materials will mainly be to develop high-performance fibers with better performance, such as high-toughness carbon fiber, ceramic fiber, etc., and explore its application in emerging fields.
Plastic has excellent corrosion resistance, high plasticity and processability, while the price is relatively low, some plastics are easy to age, easy to deform, flammable at high temperature, there is a certain pollution to the environment, plastic is a material made of polymer compounds, with lightweight, insulation, transparent and other characteristics.
At present, it is widely used in the manufacture of various containers, building materials, electrical equipment, auto parts and other fields, and the future research direction of plastic materials will mainly focus on the development of degradable plastics and new polymer materials that can replace traditional plastics, and also explore plastic recycling technology to reduce environmental pollution.
Polymer adhesive has the characteristics of strong adhesion, good weather resistance, but also can adapt to a variety of complex surface conditions, adhesive in high temperature, high humidity, ultraviolet light and other special environment performance is poor, polymer adhesive is a special material, in the manufacturing industry, building materials, packaging materials and other aspects have a wide range of applications.
In the future, the research direction of polymer adhesives will mainly focus on improving their special environmental properties such as high temperature resistance, moisture resistance and ultraviolet resistance, while exploring new adhesive technologies to improve manufacturing efficiency and finished product quality.
Polymer coatings have excellent chemical corrosion resistance and oxidation resistance, but also can provide excellent appearance decorative effects, some polymer coatings in long-term exposure to strong ultraviolet rays will appear color difference, aging and other problems.
Polymer coatings are mainly used in automobiles, buildings, machinery and equipment and other fields, with excellent corrosion resistance, fire resistance and protection performance, the future research direction of polymer coatings will be mainly to improve its coating, hardness, pollution resistance and other aspects of performance, while developing new functional polymer coatings, such as self-healing, self-cleaning coatings.
Polymer matrix composite materials have lightweight, high strength, corrosion resistance and other excellent properties, widely used in aerospace, automobiles, sports equipment and other high-end fields, some polymer matrix composites cost is high, manufacturing is difficult, polymer matrix composite is a new type of material.
It is composed of a variety of materials, with excellent comprehensive properties in performance, and the future research direction of polymer matrix composites will mainly lie in the development of new raw materials and production processes, providing more advanced materials for applications in aerospace, electronic devices and other fields.
The research of new energy vehicle battery materials is developing at an unprecedented speed, and many scientific research institutions and enterprises are exploring new and more advanced battery materials to meet people's needs for high energy density, long cycle life, low cost and other aspects.
The key factor for improving the performance of new energy vehicle batteries
Positive and negative electrode materials are the most basic components of the battery, directly affecting the capacity, power and life of the battery, the current commonly used positive electrode materials for lithium cobalt oxide, ternary materials, etc., and negative electrode materials are mainly graphite, silicon and lithium titanate.
The quality of the electrolyte determines the cycle life and safety of the battery, and the high-quality electrolyte can improve the energy density, power density and charge and discharge efficiency of the battery, while also reducing the problems of deformation and dissolution.
Interface additives can effectively improve the interface structure and stability of the battery, improve the service life and utilization rate of the battery, and many interface additives have been used in the production of new energy vehicle batteries.
For example, lithium salt additives, polymer additives, etc., the microstructure of the battery includes electrode hole structure, particle size distribution and particle shape, etc., which directly affect the performance of the battery's capacity, cycle life and energy density.
The quality of the assembly process directly affects the performance and safety of new energy vehicle batteries, and most of the current new energy vehicle batteries adopt modular design, which requires high-precision assembly equipment and technology to ensure the high safety and excellent performance of the battery pack.
Energy density refers to the stored electrical energy per unit volume or weight of the battery, and higher energy density means that the battery can provide longer range or longer service life.
For applications such as electric vehicles, higher energy density is a very important performance indicator, power density refers to the maximum output power per unit volume or weight of the battery, higher power density allows the battery to release more power in a short time, suitable for occasions that require fast charging and discharging.
Cycle life refers to how many times the battery can go through the charge and discharge cycle, still can maintain a specific electrical energy output, longer cycle life means that the battery has a longer service life, can reduce maintenance costs, battery safety includes battery stability at different temperatures, pressure and current, measures to prevent short circuit and explosion, etc., good safety performance is the basic condition that the battery must have.
The charging rate refers to the maximum charging current that the battery can withstand, the higher charging rate can shorten the charging time, the self-discharge rate refers to the rate at which the battery consumes its own power when it is not in use, and the lower self-discharge rate can reduce the power loss.
Indicators for different types of batteries will be different, in the process of battery material development, these performance parameters will usually be presented in the form of data curves or charts, through the analysis and comparison of the above indicators, can help people understand the applicability, advantages and disadvantages and manufacturing costs of batteries in different applications.
The impact of new energy on battery performance
New materials can improve the energy density of batteries in a number of ways. Some new electrode materials, such as silicon, graphene and carbon nanotubes, have a high specific surface area, which can increase the contact area between the electrode and the electrolyte, thereby increasing the capacitance and energy density.
The use of new positive and negative electrode materials, such as lithium cobalt oxide, lithium cobalt aluminate, vanadium oxide, lithium iron phosphate, etc., can improve the specific energy of the battery, and then improve the energy density, in addition, changing the structure and process of the battery also helps to improve the energy density of the battery, such as the use of thinner separators and higher material filling rates.
New materials can improve the cycle performance of batteries through different mechanisms, on the one hand, new electrode materials or electrolytes can improve the stability and durability of the battery and extend the life of the battery.
For example, using an electrolyte that enhances stability or adding a formula to prevent damage to the electrode surface can slow down the decline of the battery during the cycling process, and on the other hand, changing the structure and process of the battery can also improve the cycling performance of the battery.
For example, the use of more stable materials and more reasonable design structures can reduce the loss of electrodes and the internal resistance of the battery, thereby improving the cycle performance of the battery.
New materials can affect the temperature characteristics of the battery through different mechanisms, some new electrode materials and electrolytes have a wider temperature range and higher thermal stability, which can make the battery still work normally in a high or low temperature environment, and the structure and process of the battery will also affect the temperature characteristics of the battery.
For example, the use of better heat dissipation structure and more reasonable temperature control system can reduce the temperature rise rate of the battery and extend the service life of the battery.
New materials have an important impact on the energy density, cycle performance and temperature characteristics of the battery, and the performance of the battery will continue to be improved with the continuous emergence and application of new materials in the future.
Traditional electrode materials mainly include graphite, lithium cobalt oxide, etc., while new materials include silicon, lithium iron phosphate, sulfide, etc., while new electrode materials are mainly represented by high-capacity materials, and their specific energy is greatly improved, which helps to improve the energy density of batteries.
It generally has better stability and longer life, maintains better cycling performance, and is more affordable because the new electrode materials use a wider variety of raw materials and are cheaper to produce.
Some materials in the charge and discharge process volume expansion problem, which leads to electrode damage and battery life reduction, need to find new materials to overcome this problem, new electrode materials in the cycle life and specific energy between a certain contradiction, need to be comprehensively considered for improvement, in order to ensure the specific energy while extending the cycle life.
In the battery, the electrolyte is the medium for transferring ions, the traditional electrolyte mainly has liquid electrolyte and polymer electrolyte, while the new electrolyte includes solid electrolyte, ionic liquid, etc., and the new electrolyte usually has better conductivity and can make the battery
With better response speed and higher output power when working, solid electrolytes and ionic liquids generally have higher thermal stability and lower volatility, so they can effectively reduce the risk of battery combustion.
New electrolytes may decompose or dissolve during long-term use, and more stable formulations need to be sought to improve their stability, and some new electrolytes have higher raw material prices, and need to find lower-cost alternatives to reduce material costs.
New materials have better performance than old materials, but there is still some room for improvement, in the research and development process of new materials, it is necessary to overcome the challenges of new materials, as far as possible to exert its advantages, so as to provide more choices for future battery research and application.
Author's opinion:
In the future, with the continuous upgrading of technology and the application of new materials, we believe that battery technology will continue to be optimized to provide more reliable, efficient and safe solutions for the popularization and promotion of new energy vehicles.
Bibliography:
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