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How Do Lithium Batteries Dominate the Competition in the Face of Hundreds of Battery Technologies? An Analysis of the Structural and Material Advantages That Make Lithium Batteries Competitive |
Facing the impacts of extreme weather on the environment, many countries have joined the ranks of those aiming to reduce carbon emissions in recent years. The goal is to achieve “net zero by 2050”. To do so, they are promoting the global transition into strategies such as energy conservation, energy creation, energy storage, and smart system integration. The International Energy Agency (IEA) predicts that the global share of renewable energy will increase significantly by 2040 with the development of renewable energy power systems. However, it is estimated that the resulting demand for electricity will increase by 60%. At the same time, demands on the global electric vehicle and energy storage industries are growing increasingly urgent.
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When it comes to the field of electric vehicles, one of the key roles of new energy is the battery. Batteries alone account for 40% to 60% of the total cost. You could even say that whoever masters battery technology will have the opportunity to take the lead in the next generation electric vehicle market. |
According to the data collected by TrendForce, new energy vehicles (Including pure electric vehicles, plug-in hybrid electric vehicles, and fuel cell vehicles) will reach a sales total of 2.004 million units in the first quarter of 2022, meaning an 80% annual growth. Among these vehicle types, pure electric vehicles (BEV) show the strongest sales growth, with 1.508 units sold. In addition, IHS Markit and PwC Global estimated that electric vehicle sales already accounted for 17.9% of the overall auto market in 2021.
In 2022, the electric vehicle market grew further to 20.9 million units, and the overall electric vehicle market penetration rate further increased to 25.2%. Furthermore, electric vehicle sales are expected to officially surpass that of traditional gasoline vehicles by 2027. This trend can also be said to demonstrate how major international auto manufacturers are actively developing the electric vehicle battery market.
As for the energy storage industry, although physical energy storage in the form of pumped hydropower still accounts for the bulk, it is extremely limited by environmental conditions, so that is difficult for it to find room for growth. The fastest growing energy storage system is electrochemical energy storage. Electrochemical energy storage relies on a variety of different battery technologies, each with its own most suitable application scenarios.
At present, however, the global development of battery technology has not yet reached a consensus. According to demand, the technologies being explored by the market include: ternary lithium batteries, lithium iron phosphate batteries, cobalt-free batteries, solid-state batteries, sodium-ion batteries, and fuel cells, etc. However, the continuous increase in sales of new energy vehicles in recent years is not only promoting the great leap forward in lithium battery technology but also its large-scale application in the electric vehicle industry. Furthermore, as the size of the electric vehicle market increases, the manufacturing costs decline. What’s more, their high energy density has also made lithium batteries the most widely used batteries in electrochemical energy storage.
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Structure and Material Analysis of Lithium Batteries |
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The lithium battery’s full name is Lithium Ion Secondary Battery. The term secondary battery means that it can be repeatedly charged and discharged. In other words, it is a rechargeable battery. Lithium batteries rely mainly on lithium ions moving between positive and negative electrodes to work. When the battery is charging, the positively charged lithium ions move the electrons in the current towards the anode. During discharge, the lithium ions release electrons to generate electricity and return to the cathode through the separator. |
Figure 1. Diagram of Basic Lithium Battery Charging and Discharging Principle |
Figure 2. 3D X-ray Cross Section Observation: The 3D X-ray is a device that can perform tomography to non-destructively inspect the interior of the battery and observe its internal structure. |
Figure 3. 3D X-ray Top View. This is used to check the welding inside the battery and the alignment of the reel. |
Therefore, lithium batteries have the advantages of a high energy density, small physical size, and long cycle life that lead-acid batteries don’t have and are widely used in smart phones, tablet computers, notebook computers, wearable devices and other small, thin electronic devices as well as EV (electric vehicle) and HEV (hybrid electric vehicles) car batteries, power storage systems and other such applications.
The upstream materials for lithium batteries consist mainly of cathode materials, anode materials, electrolytes and separators. Among them, the cathode material is the key. They are about 30% to 40% of the manufacturing cost of lithium batteries, where positive and negative electrode materials together account for about 60%. At present, the cathode materials for electric vehicle batteries on the market are mainly lithium iron phosphate and ternary materials.
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Cathode Materials |
The cathode material is where the lithium ions are stored in a lithium battery. The material’s properties directly affect the energy density of the batteries and key indicators such as safety and longevity. The key to improving the energy density of lithium batteries lies in the proportion of nickel. Therefore, high nickelization is an inevitable trend in the future development of lithium batteries.
Figure 4. SEM Observation of Cathode Material Structure: The element distribution was analyzed via SEM-EDX mapping |
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Anode Materials |
Anodes are traditionally based on carbon materials, but, in the future, they will be likely to develop along various routes such as graphene, lithium titanate and silicon carbon composite materials, etc. However, the energy density of graphite anodes is only 372mAh/g, whereas, theoretically, the energy density of silicon materials can reach 4200mAh/g. Therefore, in terms of capacity, silicon anode materials have obvious advantages. Silicon-based materials also combine the high conductivity and stability of carbon materials with the high capacity of silicon materials.
 Figure 5. Crystalline Structure Analysis and Grain Size Identification Via XRD |
 Figure 6. Observation of Anode Material Structure Via SEM |
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Separators |
Battery separators are generally materials with microporous structures. These materials are mostly high-molecular weight polyethylene and polypropylene. The separator is placed between the positive and negative electrodes inside the cell, and its main function is to isolate the positive and negative plates to prevent the short-circuiting of the cathode and anode inside the battery. In practical applications, the types of separators include single-layer PP or PE separators, double-layer PE/PP composite films, double-layer PP/PP composite films, and PP/PE/PP composite diaphragms. The quality of the separator is key to ensuring the safe and stable operation of lithium batteries. The difficulties that arise lie mainly in the composite materials, strength, pore size and other related areas. Various types of separators as well as the uniformity of raw material particles can be analyzed using XRD, SEM, FTIR and other such equipment.
Figure 7. SEM Observation of the Microporous Structure of the Surface of the Separator |
Figure 8. The Functional Group Corresponding to the FT-IR Spectrum is Found to be the Spectrum of Polyethylene (PE) Through Comparison with the Database |
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Electrolytes |
The electrolyte is the liquid medium that conducts between the positive and negative electrodes in the battery. As such, it plays an important role in the performance of lithium batteries. As the trend of using lithium batteries in front-end applications continues to advance, we can expect that the demands of the new energy market will continue to promote the development of electrolytes for the next few years.
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Make Good Use of Detection and Analysis to Accelerate the Development of Lithium Batteries |
Lithium ion batteries are one of the most commonly used types of batteries for electric vehicles and energy storage. Due to impacts of the pandemic and the Russian-Ukrainian war on the global energy market, the demand for lithium ion batteries for electric vehicle energy storage has repeatedly hit new highs. Today’s battery technology is developing rapidly, and the technology research is taking various routes focused on reducing battery manufacturing costs, high cycle life, charge/discharge efficiency and high safety performance, etc. The four keys to determining the structural quality of a battery are the cathode material, anode material, electrolyte, and separator.
Facing the tide of environmental change, green energy materials have become one of the key development trends of the future, which, in turn, is driving the demand for detection and analysis. MA-tek specializes in material analysis. With the most advanced and complete analysis equipment, we provide the high-level analytical testing services needed to accelerate the product development and verification processes.
