Main content:
- Carbon materials
- Graphite anode materials
- Soft carbon
- Hard carbon
- Lithium titanate materials
- Silicon-based materials
- Nano silicon carbon material
- SiOx anode materials
- Conclusion
According to the structural classification of anode materials, this article will briefly introduce the research and development progress of various lithium-ion batteries anode materials in terms of structural characteristics, performance characteristics, and improvement directions. Focus on the development status and future trends of next-generation high-energy-density battery anode materials.
1. Carbon materials
Carbon materials are the most widely used and most common anode materials for commercial use today, mainly including natural graphite, artificial graphite, hard carbon, soft carbon, and MCNB (mesocarbon microspheres). Before the next generation of anode materials mature, carbon materials, especially graphite materials, will remain the first choice and mainstream of anode materials.
① Graphite anode materials
Graphite anode materials are divided into natural graphite and artificial graphite according to the difference of its raw material and processing technology. Due to its low lithium-ion potential, high first-time efficiency, good cycle stability, and low cost, graphite has become an ideal anode materials for current lithium-ion battery applications.
Natural graphite: Generally, natural flake graphite is used as raw material, which is modified to make spherical natural graphite for use. Although natural graphite is widely used, it has several disadvantages:
- Natural graphite has many surface defects, large specific surface area, and low initial efficiency;
- Using PC-based electrolyte, there is a serious co-intercalation phenomenon of solvated lithium ions, which causes the graphite layer to expand and peel off, and the battery performance fails;
- Natural graphite has strong anisotropy, lithium ions can only be intercalated from the end face, and the rate performance is poor and lithium is easily separated.
Modification of natural graphite:
- Aiming at the problems of many surface defects and poor electrolyte tolerance of natural graphite, different surfactants were used for modification.
- Aiming at the problem of strong anisotropy of natural graphite, mechanical treatment is often used in industrial production to spherically shape the particle morphology.
Artificial graphite: It is generally made of dense petroleum coke or needle coke as a precursor, which avoids the surface defects of natural graphite, but still has problems such as poor rate performance due to crystal anisotropy, poor low temperature performance, and easy lithium decomposition when charging.
The modification method of artificial graphite is different from that of natural graphite anode Energy Storage materials. Generally, the purpose of reducing the degree of graphite grain orientation is achieved through the reorganization of the particle structure. Usually, a needle coke precursor with a diameter of 8-10 μm is selected, and easily graphitizable materials such as pitch are used as the carbon source of the binder. Through the roller furnace treatment, several needle coke particles are bonded to form secondary particles with a particle size D50 ranging from 14 to 18 μm, and then graphitization is completed, effectively reducing the OI value of the material.
② Soft carbon
Soft carbon, also known as easily graphitizable carbon material, refers to an amorphous carbon material that can be graphitized at a high temperature above 2500 °C. Generally speaking, according to the difference in the sintering temperature of the precursor, soft carbon will produce three different crystal structures, namely amorphous structure, turbulent layer disordered structure and graphite structure. The graphite structure is also the common artificial graphite.
Among them, the amorphous structure has attracted widespread attention because of its low crystallinity, large interlayer spacing, and good compatibility with the electrolyte, so it has excellent low-temperature performance and good rate performance. Soft carbon anode materials have high irreversible capacity, low output voltage, and no obvious charge-discharge platform when it is charged and discharged for the first time. Therefore, it is generally not used independently as anode materials, but is usually used as anode materials coating or component.
③ Hard carbon
Hard carbon, also known as non-graphitizable carbon material, is difficult to graphitize at high temperatures above 2500°C, and is generally obtained by heat treatment of the precursor in the range of 500-1200°C. Common hard carbons include resin carbon, organic polymer pyrolytic carbon, carbon black, and biomass carbon. Among them, phenolic resin can be pyrolyzed at 800°C to obtain hard carbon materials, and its initial charging capacity can reach 800mAh/g.
The application of hard carbon mainly considers the matching with cathode materials. The performance of Lithium Ion Battery Manufacturer with lithium-rich materials as cathode materials and hard carbon as anode materials has been studied. It is found that the matching of the two materials can help reduce their respective initial irreversible capacities. Lithium-ion batteries prepared by using hard carbon as the anode materials and LFP as the cathode material by LIAO showed good rate performance and cycle performance, and the capacity retention rate was still more than 60% after 2000 cycles at 10°C.
2. Lithium titanate materials
Lithium titanate (LTO) is a composite oxide composed of metallic lithium and low-potential transition metal titanium, which belongs to the spinel solid solution of the AB2X4 series. The theoretical gram capacity of lithium titanate battery is 175mAh/g, and the actual gram capacity is greater than 160mAh/g. It is one of the anode materials that have been industrialized at present.
Pros:
- Zero strain: The lithium titanate unit cell parameter a=0.836nm, the intercalation and deintercalation of lithium ions during charge and discharge have little effect on its crystal structure. It avoids structural changes caused by material stretching during charging and discharging, so it has extremely high electrochemical stability and cycle life;
- No risk of lithium analysis: Lithium titanate has a potential of up to 1.55V for lithium, no SEI film is formed on the first charge, high initial efficiency, good thermal stability, low interface impedance, excellent low-temperature charging performance, and can be charged at -40°C;
- Three-dimensional fast ion conductor: Lithium titanate is a three-dimensional spinel structure, the intercalation space of lithium is much larger than that of graphite layer, and the ion conductance is an order of magnitude higher than that of graphite material, which is especially suitable for high-rate charge and discharge.
Cons:
- Lithium titanate also has low battery specific energy due to its low gram capacity and low voltage platform.
- Nano-materials have strong hygroscopicity, resulting in serious high-temperature gas production and poor high-temperature circulation. The material manufacturing process is complex and the cost is extremely high.
- The cost of the battery cell is more than three times that of a lithium iron phosphate battery with the same energy.
The pros and cons of lithium titanate are very obvious, and the performance is relatively extreme. Therefore, it is the correct application method to apply to specific subdivision fields and give full play to its strengths. At present, lithium titanate batteries are mainly used in urban pure electric BRT buses, electric hybrid buses, power frequency modulation peak shaving auxiliary services and other fields.
3. Silicon-based materials
Silicon is considered to be one of the most promising anode materials. Its theoretical gram capacity can reach 4200mAh/g, which is more than 10 times higher than that of graphite materials. At the same time, the lithium intercalation potential of Si is higher than that of carbon materials, and the risk of lithium deposition during charging is small and safer. At present, the research hotspots of silicon-based materials are divided into two directions, namely nano-silicon carbon materials and silicon-oxygen (SiOx) anode materials.
① Nano silicon carbon material
The initial research on nano-silicon carbon materials mainly focused on the low capacity direction of 400-500mAh/g, and the material structure mainly includes core-shell type and embedded type. In addition to material design, the chemical system of the battery is optimized by studying the binder, conductive agent and electrolyte, and the 600-cycle capacity retention rate of 400mAh/g silicon carbon material is more than 80%.
On this basis, by optimizing the particle structure, high-power materials are developed. At present, lithium-ion batteries made of low-capacity materials have been mass-produced in the industry, but from the actual results, the improvement of battery specific energy is extremely limited.
② SiOx anode materials
The reversible capacity of SiOx anode materials is as high as 1500-2000mAh/g, and the volume expansion during lithium intercalation is only 120%, which greatly improves the cycle life of Si-based materials. However, during the first intercalation process of SiO material Li, Li4SiO4 with no electrochemical activity will be generated, resulting in the initial efficiency of SiOx anode materials being much lower than that of graphite and silicon carbon materials, which has also become the main obstacle to the application of SiOx anode materials.
Therefore, the research on SiOx anode materials mainly focuses on how to reduce the initial irreversible capacity. For this reason, researchers have developed different methods of lithium supplementation, trying to compensate for the active lithium consumed by the anode during the first charging process. Due to the high requirements on the environment, the pre-lithiation process of SiOx anode materials is still in the laboratory stage and cannot be applied in a large scale. Therefore, the follow-up research will focus on the pre-lithiation of cathode materials and the pre-lithiation of SiOx anode materials.
4. Conclusion
This article summarizes the structural and functional characteristics of various anode materials for lithium-ion batteries, and reviews the latest research progress of various anode materials in lithium-ion batteries. At present, silicon-based anode materials in silicon based anode companies in the world have become the most promising next-generation anode materials, but the inherent characteristics of large volume expansion and poor cycle performance limit large-scale applications.
Most of the modification methods proposed in recent years have the problems of complex process and high cost. This requires researchers to continuously strengthen their understanding of the basic principles and develop simple and efficient methods to prepare composite nano-Si-based materials. Focusing on the development of lithium-ion batteries with low expansion, high first effect, high rate, safety and friendliness, it is hoped that silicon anode materials will replace graphite as soon as possible and achieve breakthroughs in the field of electric vehicles.
Related articles:natural graphite,silicon based
FAQs
What is the material used as the anode for a lithium-ion battery? ›
The anode (or negative electrode) in Lithium-ion battery is typically made up of Graphite, coated on Copper Foil.
What are the characteristics of anode material? ›Anode materials should be highly conductive to achieve a high performing and efficient device. The conductivity, WF and transparency of the anode can be varied by the surface treatment of the substrate and the deposition technique.
What are the materials used in lithium batteries cathode and anode? ›The anode (negative electrode) of a conventional lithium-ion cell is typically graphite made from carbon. The cathode (positive electrode) is typically a metal oxide. The electrolyte is typically a lithium salt in an organic solvent.
What are the characteristics of lithium-ion battery? ›Lithium-ion batteries are common in consumer electronics. They are one of the most popular types of rechargeable battery for portable electronics, with one of the best energy-to-weight ratios, high open circuit voltage, low self-discharge rate, no memory effect and a slow loss of charge when not in use.
How does a lithium anode work? ›The anode and cathode store the lithium. The electrolyte carries positively charged lithium ions from the anode to the cathode and vice versa through the separator. The movement of the lithium ions creates free electrons in the anode which creates a charge at the positive current collector.
Why lithium is preferred as anode in most battery? ›One of the main attractions of lithium as an anode material is its position as the most electronegative metal in the electrochemical series combined with its low density, thus offering the largest amount of electrical energy per unit weight among all solid elements.
What are the 5 characteristics of anode rays? ›- Anode rays are always moving in a straight direction.
- These rays are made up of ions or particles.
- Magnetic and electric fields deflect these rays.
- When deflected, they travel towards negative late so they are positive.
- Anode rays lead to mechanical motion.
To correct these deficiencies, alloy anodes (such as Aluminum (Al), Tin (Sn), Magnesium (Mg), Silver (Ag), Antimony (Sb), and their alloys) are used. Alloy anodes are known to have a specific capacity that is two to ten times higher than that of anodes made of carbon material.
What are the 3 components of the anode? ›Copper, molybdenum, and graphite are the most common anode materials. Adequate heat dissipation is the major engineering hurdle in designing higher capacity x-ray tubes.
What are the characteristics of cathode and anode materials? ›Cathode rays contain material particles (electrons) which are negatively charged. Anode rays contain material particles which are positively charged. These rays are deflected in both magnetic and electric fields. These rays are deflected in both magnetic and electric fields.
What is the most common cathode material for lithium ion battery? ›
Iron disulfide (FeS2) is widely used as cathode material for non-rechargeable Li-ion batteries.
What are the most common anode materials? ›Currently, the two most commonly used anode materials are those based on carbon (graphite) and lithium alloyed metals.
What are the 3 main components of a lithium battery? ›Li-ion batteries consist of largely four main components: cathode, anode, electrolyte, and separator.
What are 3 characteristics of lithium? ›Uses and properties
A soft, silvery metal. It has the lowest density of all metals. It reacts vigorously with water. The most important use of lithium is in rechargeable batteries for mobile phones, laptops, digital cameras and electric vehicles.
Between the most significant properties of lithium we find its high specific heat (calorific capacity), the huge temperature interval in the liquid state, high termic conductivity, low viscosity and very low density.
What are the advantages of lithium anode? ›Lithium (Li) metal is an ideal anode material for rechargeable batteries due to its extremely high theoretical specific capacity (3860 mA h g−1), low density (0.59 g cm−3) and the lowest negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode).
Why is the anode of a lithium-ion battery negative? ›Anode and Cathode
A vacuum tube, diode or a battery on charge follows this order; however taking power away from a battery on discharge turns the anode negative. Since the battery is an electric storage device providing energy, the battery anode is always negative.
Li-ion batteries consist of largely four main components: cathode, anode, electrolyte, and separator.
What is a disadvantage of lithium-ion batteries? ›Despite its overall advantages, lithium-ion has its drawbacks. It is fragile and requires a protection circuit to maintain safe operation. Built into each pack, the protection circuit limits the peak voltage of each cell during charge and prevents the cell voltage from dropping too low on discharge.
Which battery is more efficient than lithium-ion battery? ›Sodium-ion battery charges faster than lithium-ion variants and have a three times higher lifecycle.
Why is lithium not being used in current commercial lithium-ion batteries? ›
It uses up the electrolyte and reduces battery life. An additional problem is that the anode and electrolyte produce heat when they come into contact. Lithium batteries, including those in use today, can overheat to the point of fire, or even explosion. They are, therefore, a serious safety concern.
What is the difference between the anode and the cathode? ›The anode is the electrode where electricity moves into. The cathode is the electrode where electricity is given out or flows out. The anode is usually the positive side. A cathode is a negative side.
What color is positive anode? ›On an electrophoresis power source, the anode (positive charge) is red, and the cathode (negative charge) is black.
Do anode rays have mass or charge? ›anode rays are positively charged beam made up of positive ions or we can say that positive residence of atom.
What is the best anode material? ›Aluminum anode alloy provides more protection and lasts longer than zinc. It will continue to work in freshwater and is safe for use in salt water. Aluminum is the only anode that is safe for all applications.
Why graphite is used as anode in lithium-ion battery? ›Graphite is the most commonly used to serve as the anode material in lithium-ion battery manufacturing due to its relatively low-cost and its energy density. Graphite has great conductive properties and for the most part is readily available.
Which metal is most often used for the anode of a battery? ›Graphite is the most commonly used anode material due to its high electrical conductivity, low cost, and stable structure. Silicon anodes offer higher energy density but face challenges in terms of volume expansion and shorter cycle life.
What are the two types of anodes? ›The two categories of X-ray anodes are stationary and rotating. As you might guess from the names, the main difference here is that one anode stays still (stationary) while the other spins around a fixed point (rotating).
How many types of anodes are there? ›Sacrificial anodes are generally cast in three basic geometric shapes: the long, slender, stand-off type; the flat-plate, flush-mounted type; and the bracelet type. In most cases, anode selection is performed by the owner, taking into account effects like sea current drag and interference with subsea interventions.
Which metal is used at the anode? ›Anode materials
There are three main metals used as galvanic anodes: magnesium, aluminum and zinc.
What is the best cathode and anode material for electrolysis? ›
Steel and iron are the most commonly used for electrolysis of water. These electrodes are used as anode and it is sacrificed in electrolysis, as the anode rusts (get oxidized) and the cathode de-rusts (get reduced).
What is an example of an anode? ›Examples of Anode
A simple example is electrolysis of water. A positively charged platinum electrode where H2 gas is oxidized to H+ ions is the anode. The anode is the positive terminal that receives current from an external generator in a recharging battery.
- Anode: The anode is where the oxidation reaction takes place. In other words, this is where the metal loses electrons. ...
- Cathode: The cathode is where the reduction reaction takes place. This is where the metal electrode gains electrons.
Graphite is currently widely used as the anode in lithium-ion batteries. These EV battery chemistries depend on five critical minerals whose domestic supply is potentially at risk for disruption: lithium, cobalt, manganese, nickel, and graphite.
What is the positive electrode material for lithium batteries? ›The positive electrode materials for lithium and lithium-ion batteries are usually transition metal oxides or sulfides. In lithium ion batteries, the positive electrode materials used are lithiated transition metal oxides, as the cathode side in these systems is also the initial source of lithium in the electrodes.
What is the new anode material? ›The new two-dimensional (2D) anode material is developed using Nano sheets derived from titanium diboride (TiB2), which resemble a stack of sandwiches, where metal molecules exist between layers of boron.
What is the most efficient anode? ›Silicon anodes are particularly interesting to automakers and cell producers alike — in theory, silicon anodes are 10x more energy efficient than industry-standard graphite anodes.
What is the most expensive component of a lithium battery? ›The single most expensive element of an EV battery is the cathode, which accounts for up to a third of the cost of a battery cell. Most EV batteries today use one of two types of cathodes: Nickel cobalt manganese (NCM) or lithium iron phosphate (LFP).
What is the difference between lithium battery and lithium ion battery? ›The main difference between lithium batteries and lithium-ion batteries is that lithium batteries are primary cells and lithium-ion batteries are secondary cells. The term "primary cell" refers to cells that are not rechargeable. on the other hand, lithium-Ion batteries feature secondary cell construction.
What are 3 negative features of lithium-ion batteries? ›Drawbacks or disadvantages of Lithium Ion Battery
➨It lasts only two to three years after manufacturer. ➨It is sensitive to high temperatures. ➨If the battery is completely discharged, it can no longer be recharged again. ➨It is relatively expensive.
What happens when lithium reacts with water? ›
Lithium reacts intensely with water, forming lithium hydroxide and highly flammable hydrogen. The colourless solution is highly alkalic. The exothermal reactions lasts longer than the reaction of sodium and water, which is directly below lithium in the periodic chart.
What are 4 interesting facts about lithium? ›- Although it is a metal, it is soft enough to cut with a knife.
- It is so light it can float on water.
- Lithium fires are difficult to put out. ...
- Along with hydrogen and helium, lithium was one of the three elements produced in large quantities by the Big Bang.
Lithium-ion batteries (Li-ion) have many desirable characteristics such as high efficiencies, a long cycle life, high energy density, and high power density (Table 2) [4]. These characteristics, along with their capability for fast discharge, have made them nearly ideal for portable electronics applications.
Are there different qualities of lithium batteries? ›Based on electrode materials, there are six different types of lithium cells: LFP, NMC, LCO, NCA, LTO, and LMO. Based on the cell shape, there are three types of lithium-ion batteries- cylindrical, pouch, and prismatic, each with distinct battery performance parameters.
What are the physical properties of a lithium battery? ›Lithium's major characteristics are, its extremely low density, low viscosity, high thermic conductivity, high specific heat, and in the state of liquid there is a huge temperature interval. In hydrocarbons, it is insoluble, whereas, in short-chain aliphatic amines, the metallic lithium is soluble.
Is graphite the anode in lithium ion battery? ›Graphite is a perfect anode and has dominated the anode materials since the birth of lithium ion batteries, benefiting from its incomparable balance of relatively low cost, abundance, high energy density, power density, and very long cycle life.
What is anode in lithium-ion cell? ›The anode, also known as the negatively charged electrode, discharges lithium ions into the electrolyte as shown in Fig. 1. The discharged ions are subsequently conveyed to the cathode, which is also referred to as the positively charged electrode, where they are absorbed.
What materials are used on the cathode of a lithium ion battery? ›Cathode materials are comprised of cobalt, nickel and manganese in the crystal structure forming a multi-metal oxide material to which lithium is added. This family of batteries includes a variety of products that cater to different user needs for high energy density and/or high load capacity.
What is a downside of using graphite for the anode in a battery? ›Issue. Typical graphite anode materials can experience high irreversible loss due to large surface areas, which consume available Li+ ions, and therefore reduce the battery energy density.
What are the problems of graphite anode in lithium-ion battery? ›Graphite-based anode materials undergo electrochemical reactions, coupling with mechanical degradation during battery operation, can affect or deteriorate the performance of Li-ion batteries dramatically, and even lead to the battery failure in electric vehicle.
What is the difference between graphite and graphene anodes? ›
With traditional graphite anodes, lithium ions accumulate around the outer surface of the anode. Graphene has a more elegant solution by enabling lithium ions to pass through the tiny holes of the graphene sheets measuring 10–20nm. This promises optimal storage area and easy extraction.
Why is the anode of a lithium ion battery negative? ›Anode and Cathode
A vacuum tube, diode or a battery on charge follows this order; however taking power away from a battery on discharge turns the anode negative. Since the battery is an electric storage device providing energy, the battery anode is always negative.
When naming the electrodes, it is better to refer to the positive electrode and the negative electrode. The positive electrode is the electrode with a higher potential than the negative electrode. During discharge, the positive electrode is a cathode, and the negative electrode is an anode.
What makes a good anode and cathode? ›The most desirable anode-cathode material combinations are those that result in light-weight cells with high voltage and capacity.
What is the best cathode material for batteries? ›Materials Good for Cathodes
Metallic oxides make excellent cathode materials because they have a useful working voltage as well. These include copper oxide, lithium oxide, and graphic oxide.