electrode thickness: A Crucial Factor in 4680 Battery DesignAn Introduction to Efficient Battery Design ToolsCOMSOL software enables the creation of a user-friendly battery design app, essential for exploring the impact of electrode thickness on battery performance. The design app simplifies the battery customization process, featuring key functionalities such as parameter reset and calculation.User Interface for Battery Design OptimizationThe electrode thickness impact on performance is central to the app's parameter interface, which requires input of battery model, size, thermal and charge-discharge load parameters. The app allows the selection of cylindrical batteries, specifically customizing them to a 46mm diameter and 80mm height. The volume utilization rate, influenced by electrode thickness, is fine-tuned to align with Tesla 4680 battery specifications, concluding at 91% to approximate a 22.3Ah capacity.Core Components of the 4680 Battery ModelThe model consists of elements vital for examining electrode thickness, including the negative and positive electrode current collectors and coatings, and separators. The design specifies current collector thickness at half of its actual measurement, with the electrode thickness focused on single-sided coatings.Insights from Tesla 4680 Battery DisassemblyDisassembled Tesla 4680 batteries provide reference data on electrode thickness: 15 microns for positive current collector (Al), 8 microns for negative current collector (Cu), 174.4 microns for the positive electrode plate, and 262 microns for the negative electrode plate.Electrode Parameters Influenced by ThicknessDrawing from Tesla's design, the positive electrode uses NMC811. The electrode thickness informs the calculation of active material volumes, assuming a 95% composition. The density of single-sided surfaces, linked to electrode thickness, was determined at 26.58 mg/cm2 for positive and 17.5 mg/cm2 for negative electrodes. Volume fractions derived from electrode thickness data estimate 68.3% for positive and 57.9% for negative materials.Understanding electrode thickness is essential for optimizing 4680 battery design, impacting the performance and efficiency of new-generation batteries.Quote InquiryContact us

Breakthrough in Ultra-Low Temperature FAN electrolyte TechnologyIntroduction to FAN ElectrolyteProfessor Fan Xiulin's recent publication in Nature has introduced a groundbreaking ultra-low temperature electrolyte known as FAN, composed of 1.3M LiFSI/FAN. This advanced electrolyte exhibits impressive conductivity levels of 40.3mS/cm at room temperature and 11.9mS/cm at -70°C. The FAN electrolyte operates effectively in high-energy density lithium-ion batteries, supporting 4.5V NCM811/Gr pouch cells with a surface capacity of 2.85mAh/cm2 over a broad temperature range from -70°C to 60°C.Unprecedented Performance at Low TemperaturesThe FAN electrolyte is capable of rapid charging and discharging within 10 minutes, underpinned by the "ligand channel promoted transport" mechanism. It offers a capacity retention rate of 96% at -35°C and 80% at -60°C, maintaining performance for up to 350 cycles. Traditional EC/EMC-based electrolytes fail under low temperature conditions, making the FAN electrolyte a milestone in the field.Development and Selection ProcessDeveloping this extraordinary electrolyte required meticulous screening of 23 possible solvents, with analysis focusing on lithium ion solvation energy, solvation sheath volume, and transport energy barriers. Ultimately, water (H2O), acetonitrile (AN), and fluoroacetonitrile (FAN) were selected. FAN emerged as the most viable solvent, capable of forming a stable solid electrolyte interface (SEI) under demanding conditions.Scientific Validation and Reaction MechanismNitrile additives enhance lithium-ion batteries’ high-temperature performance and thermal stability by forming partially coordinated compounds, reducing parasitic reactions. Acetonitrile forms complexes with lithium through lone pair electrons, which is problematic. However, the electron-withdrawing fluorine in FAN diminishes the lone pair's ability to form coordination compounds with lithium, offering enhanced stability as an electrolyte.The Future of Electrolyte InnovationThe FAN electrolyte exemplifies how understanding coordination bonds and electron cloud theory can lead to breakthroughs in battery technology. By modifying coordination between graphite and Li+, the theoretical capacity of graphite could potentially exceed current expectations. The advancements in electrolyte chemistry are laying the foundation for more efficient and durable lithium-ion batteries across varied temperatures and conditions.Quote InquiryContact us

Semi solid state battery: The Future of Energy StorageA semi solid state battery represents a breakthrough in battery technology by merging the features of both solid and liquid electrolytes. This innovation is primarily aimed at enhancing lithium-ion batteries, boasting high ionic conductivity within the electrolyte. Among cutting-edge battery technologies, semi solid state batteries stand out due to their high energy density, increased safety, extended lifespan, and minimal environmental impact, positioning them as a leading contender in advanced energy storage solutions.Types of Semi Solid State BatteriesSemi solid state batteries can be categorized into three main types: gel polymer type, clay type, and liquid additive type.Gel Polymer Type Semi Solid State BatteryThis variant is a flexible battery utilizing a gel electrolyte. It showcases impressive bending resistance and rapid charging capabilities, making it ideal for card-sized and wearable devices.Clay Type Semi Solid State BatteryThis type takes inspiration from clay, with electrolytes integrated into the electrode. It features an extended service life and reduced risks of liquid leaks and fires, rendering it suitable for solar power generation and automotive applications.Liquid Filled Type Semi Solid State BatteryThis battery is constructed from ceramic, with electrolyte minimally absorbed inside. It offers excellent thermal stability and is viable for high-temperature applications, such as the Internet of Things, industrial equipment, and automotive interiors.Electrolytes in Lithium-Ion BatteriesBatteries, including semi solid state batteries, charge and discharge as ions move between the positive and negative electrodes. In traditional lithium-ion batteries, where the electrolyte path is crucial, the use of flammable liquid electrolytes has prompted the development of safer alternatives, such as all solid state and semi solid state batteries.Comparing Other Battery TechnologiesLithium Iron Phosphate BatteryThis battery uses iron phosphate (LiFePO4) in its positive electrode, offering cost-effectiveness and thermal stability. With a lengthy lifespan and many charge cycles, these batteries have a reduced environmental impact due to the non-use of rare metals.Ternary Lithium-Ion BatteryThese batteries incorporate ternary compounds like nickel cobalt manganese (NCM) or nickel cobalt aluminum (NCA) in the positive electrode. Despite high energy density and performance at low temperatures, they involve expensive rare metals like cobalt, increasing risks of thermal runaway and ignition.ConclusionSemi solid state battery technology is a promising frontier in advancing energy storage applications. Given its remarkable advantages over existing solutions, such as lithium iron phosphate and ternary lithium-ion batteries, it is a forward-looking choice for safer, efficient, and environmentally friendly power systems.Quote InquiryContact us

Understanding capacity retention rate in Lithium-Ion BatteriesWhat is Capacity Retention Rate?Capacity retention rate is a critical parameter in evaluating lithium-ion batteries and other secondary batteries. As these batteries undergo various battery evaluation tests, such as cycling tests, float charging tests, and storage tests, they experience deterioration, leading to a decrease in their capacity from the original value, measured in mAh or Ah. The capacity retention rate is calculated as the ratio of the current capacity (mAh or Ah) to the initial capacity, multiplied by 100. In simpler terms, it represents the remaining capacity as a percentage of the initial capacity, initially set at 100%.Example of Capacity Retention Rate in Cycle TestingDuring cycle testing, which assesses battery degradation through repeated charging and discharging, the capacity retention rate serves as a key evaluation metric. The graph demonstrating capacity retention rate in this context typically shows the percentage of capacity retained on the vertical axis against the number of cycles on the horizontal axis. A battery that sustains a high capacity retention rate after numerous cycles is considered to be of high quality.Factors Influencing Capacity Retention RateSeveral elements impact the capacity retention rate of a battery apart from cycle count. These include the charging and discharging rates during cycles, ambient temperature, and others. The decline in capacity retention rate can be estimated using degradation coefficients such as Kc in cycle tests and Kf in float tests. The formula is: reduction in capacity retention rate = Kc x square root of cycle tests + Kf x time in storage.Key ConsiderationsOne important factor in cyclic testing is the depth of discharge (DOD). A larger DOD leads to more significant expansion and contraction of the active materials during charge-discharge cycles, increasing contact resistance and affecting the capacity retention rate. Another caution is the electrolyte amount in the battery. Insufficient levels can lead to drying up (liquid depletion), severely affecting the capacity retention rate.Quote InquiryContact us

Understanding Internal Resistance in Lithium-ion batteriesThe Importance of Internal Resistance in Lithium-ion BatteriesThe internal resistance of lithium-ion batteries is a vital factor in determining their overall performance. It influences key attributes like charge and discharge efficiency, power output, thermal management, and aging rate.Methods for Measuring Internal Resistance in Lithium-ion BatteriesThree primary methods are used to test the internal resistance of lithium-ion batteries: DC internal resistance (DCIR), AC internal resistance (ACIR), and electrochemical impedance spectroscopy (EIS).DC Internal Resistance (DCIR) in Lithium-ion BatteriesThe DCIR method involves applying a small DC pulse current to lithium-ion batteries and measuring the voltage change. Using Ohm's law (V=IR), the internal resistance is calculated. This method provides a quick assessment of battery health and performance. The IEC 61960 standard suggests using discharge pulses to derive DCIR values.AC Internal Resistance (ACIR) for Lithium-ion BatteriesACIR tests are performed by applying a small AC signal to the lithium-ion battery and measuring the AC response. This method, typically conducted at 1 kHz, allows for the analysis of impedance without the interference from low-frequency electrochemical processes.Electrochemical Impedance Spectroscopy (EIS) in Lithium-ion BatteriesEIS is a more complex technique used to analyze the impedance properties of lithium-ion batteries over a range of frequencies. It provides comprehensive insight into the battery's internal electrochemical processes, making it invaluable in research and development.Comparing DCIR and ACIR in Lithium-ion BatteriesACIR offers fast and highly reproducible measurements and is ideal for quick battery inspections. DCIR, although less reproducible, provides a more accurate representation of a lithium-ion battery's internal resistance during real-world use.Normalized Internal Resistance in Lithium-ion BatteriesAccording to manufacturer specifications, the normalized internal resistance for commercial LFP lithium-ion batteries typically ranges from 35 to 70 mΩ*Ah.Quote InquiryContact us

Exploring Double-layer coating technology in Lithium-Ion Battery ProductionIntroduction to Double-Layer Coating TechnologyThe innovative double-layer coating technology is reshaping the design of electrode pieces for lithium-ion batteries. This multi-layer architectural approach boosts performance, creating a "high-speed channel" for ions and electrons, thereby minimizing diffusion resistance and mitigating capacity loss. A key focus is the gradient distribution of electrode porosity, employing a high porosity upper layer and a dense lower layer to balance energy density and rapid charging capabilities.Advancements in Double-Layer Coating TechnologyDeveloped in tandem with the need to enhance production efficiency, the double-layer coating technology advances electrode performance by utilizing two distinct slurries. Examples of double-layer structure electrodes include:Binder Layering: To address adhesion issues caused by adhesive migration during coating drying, the lower slurry in the double-layer coating may be enriched with a high ratio of SBR.Conductive Agent Hierarchy: Maintaining equal total conductive agent content, studies reveal better battery performance with higher conductive agent concentration near the current collector.Particle Stratification: Differentiation in particle types and sizes allows dual energy density and power characteristics within the same battery design.Porosity Layers: Gradual porosity in the electrode's double-layer structure enhances lithium ion migration, boosting electrochemical performance at elevated current densities.Challenges and Solutions in Double-Layer Coating TechnologyThe double-layer coating technology faces several challenges, such as a narrower process window compared to single-layer applications. Major issues include air entrainment, slurry mixing, and coating stability affected by viscosity and surface tension differences. Optimizing these parameters is crucial for achieving high-quality double-layer coatings.Experimental findings (e.g., Figures 9, 10, 11, 12) demonstrate that the ultimate coating thickness achievable with double-layer coating technology surpasses single-layer applications, though with limitations in speed stability. Adjustments in flow ratio, viscosity, and tension are critical for successfully navigating the process window.Future Prospects of Double-Layer Coating TechnologyDespite limited studies, the advantages of double-layer coating technology in lithium-ion battery production are apparent. For optimal outcomes, meticulous control over slurry properties and process parameters is essential for a stable and uniform double-layer coating.ConclusionThe implementation of double-layer coating technology is crucial for advancing lithium-ion battery efficiency. By leveraging intricate multi-layer structures, this approach offers superior battery performance and high-speed charging capabilities.Quote InquiryContact us

AB Simultaneous coating technology on both sidesIntroduction to AB Simultaneous Coating TechnologyIn the 2010s, traditional lithium-ion battery coating machines typically employed a single-sided coating method. This required pole pieces to be coated twice—first on side A, dried, then rewinded for side B coating. However, advancements led to the development of double-sided coating machines designed for foldback processing, offering substantial improvements in efficiency.Emergence of Simultaneous Coating TechnologyRecent innovations have introduced AB Simultaneous Coating Technology on Both Sides, enabling both sides to be coated and dried concurrently. This new approach minimizes repetitive actions and significantly enhances coating efficiency.Patent Advancements in Simultaneous CoatingIn 2016, Professor Zhao Boyuan patented a "Simultaneous Double-sided Extrusion Coating Device." This device utilizes front and back coating units that coat substrates in a vertical upward direction. Air flotation steering converts this upward movement into horizontal, ensuring non-contact drying for superior coating results.Panasonic's Two-sided Coating DevicePanasonic’s two-sided coating device emphasizes tensioning and substrate stabilization using a specialized adsorption mechanism. The uniform floating of substrates is achieved through positive and negative pressure balance, culminating in precise two-side coating using a floating drying oven.Commercial Applications and InnovationsCompanies like Golden Galaxy and Dürr have launched commercial solutions employing AB Simultaneous Coating Technology on Both Sides. These machines feature high-speed coating dies and unique floating ovens, overcoming challenges like jitter and ensuring quality and performance enhancements in lithium batteries.Key Innovations in AB Simultaneous Coating TechnologyDevelopment of combined extrusion coating dies for high-precision application.Introduction of floating high-speed ovens with optimized air supply structures.Addressing jitter issues to ensure consistent coating and drying processes.Utilizing enhanced tension control and deviation correction systems.Research and Development in AB Simultaneous Coating TechnologyResearch teams have been focusing on improving coating uniformity using contact coating dies. Studies reveal that contact dies significantly reduce gap fluctuation, optimizing the coating process.Modeling and Simulation for ImprovementAdvanced models involving fluid dynamics and VOF two-phase flow have been developed to simulate second-side coating scenarios, providing valuable insights into factors affecting coating consistency and quality.The Future of AB Simultaneous Coating TechnologyAs obstacles such as stable coating without back rollers and complete floating dries are conquered, AB Simultaneous Coating Technology on Both Sides is set to become the mainstream in lithium-ion battery manufacturing, promising continuous advancements in the industry.Quote InquiryContact us

Unveiling the Secrets of Sodium-ion batteries: Disassembly and AnalysisSodium-ion batteries have emerged as a promising alternative energy storage solution. This article delves into the meticulous process of disassembling sodium-ion batteries and inspecting their components.Electrolyte Extraction and Analysis in Sodium-Ion BatteriesTo extract the electrolyte from sodium-ion batteries, the discharge process is initiated at a constant current-constant voltage of 600mA until reaching 1.5V and current drops to 1mA. Then, under argon protection in a glove box, the battery's cover is removed. The cells of the sodium-ion batteries are secured for extraction with a special holder that features an auto-injection vial and placed in a centrifuge tube fit for centrifuge analysis.The centrifuge starts at 4,000 rpm, reaching 10,000 rpm over 6 hours to extract the electrolyte from sodium-ion batteries successfully. Typically, around 3.4 grams of electrolyte is extracted, diluted with methylene chloride, and its composition analyzed using GC-MS. The key solvents extracted from the sodium-ion batteries include dimethyl carbonate (DMC), methyl ethyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), and ethyl propionate (EP).Conductive Salt Analysis in Sodium-Ion BatteriesA 200 μL sample of the electrolyte underwent ICP-OES examination for sodium salt content, revealing an average sodium concentration of 1.42 mol/L with NaPF6 as the primary conductive salt for sodium-ion batteries.Detailed Solvent Composition with GC-FIDThe relative solvent ratios of sodium-ion batteries' electrolyte were quantified via GC-FID analysis, showing an average composition of 41.8 wt% DMC, 15.2 wt% EMC, 14.3 wt% EP, 7.3 wt% EC, and 21.4 wt% PC.Active Material Analysis in Sodium-Ion BatteriesExploring the constituents of sodium-ion batteries, samples from electrodes were dissolved and analyzed through ICP-OES. An analysis of SEM-EDX further revealed the elemental distribution in sodium-ion batteries' electrodes.Cathode Composition and StoichiometryThe cathode in sodium-ion batteries was determined to be Ni/Mn/Fe in equal parts, leading to the composition Na0.96Ca0.02Nix0.33Mny0.33Fez0.33O2 layered oxide, while the anode remains hard carbon.Pore Structure Analysis in Sodium-Ion BatteriesInvestigating the pore structure of sodium-ion batteries, mercury intrusion assessment revealed the highest porosity in diaphragms at 40.6%, with specific pore sizes prevalent at 87.5 nm for diaphragms and larger sizes for electrodes.Imaging and TopographyThe structural imaging from CT scans provided insights into the topography of the cathode and anode in sodium-ion batteries, contributing to a deeper understanding of their physical attributes and operational efficiency.Quote InquiryContact us

Lithium battery paste: An Essential Component in Battery ManufacturingIntroduction to Lithium Battery Paste and Its ImportanceThe lithium battery paste is pivotal to the manufacturing of lithium-ion batteries. It affects both the performance and quality of electrode pieces, directly influencing key attributes like voltage, energy density, cycle life, rate performance, and safety.Key Characteristics of Quality Lithium Battery PasteA top-notch lithium battery paste is defined by high solids content, even distribution, moderate viscosity, and finely dispersed particles. These traits ensure a uniform coating, enhance storage stability, and improve overall battery performance while maintaining safety.Challenges in Lithium Battery Paste ManufacturingPoor quality in lithium battery paste often stems from raw material issues, flawed preparation processes, and inadequate environmental controls. Impurities, uneven particle sizes, improper mixing, and environmental factors all contribute to undesirable outcomes like residual bubbles, affecting uniformity and stability.Significance of Raw Material and Environmental ControlTo produce superior lithium battery paste, manufacturers must select high-quality raw materials, optimize the preparation process, and ensure controlled environmental conditions. Addressing these aspects reduces risks and enhances the manufacturing process.Innovative Solutions for Monitoring Lithium Battery PasteLingsheng Technology introduces a cutting-edge ultrasonics-based solution for monitoring lithium battery paste quality in real-time. This system leverages non-invasive ultrasonic probes and advanced algorithms for detecting and managing anomalies like bubbles and agglomerates during the pulping stage.Advantages of Real-Time Slurry Quality MonitoringBy setting parameter standards, this innovative system assesses the need for secondary deaeration of lithium battery paste. This process reduces scrap rates and refines the coating process, ensuring the delivery of high-quality batteries.Quote InquiryContact us