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

Rheology of the slurry: A Key Factor in Electrode Coating ProcessabilityThe rheology of the slurry plays a crucial role in processing lithium-ion battery electrodes. This slurry is a non-Newtonian fluid, showcasing pseudoplastic characteristics by decreasing viscosity under shear. The viscosity of the slurry is a critical determinant in the electrode coating processability, influencing coater pressure, speed, and slurry stability.Slurry Dynamics and ViscosityUnderstanding the rheology of the slurry highlights its nature as a shear-rate-dependent fluid. Unlike Newtonian fluids with consistent viscosity regardless of shear, non-Newtonian fluids like the slurry exhibit variable viscosity. Specifically, the slurry displays shear thinning; its viscosity decreases as shear rate increases.Microscopic Mechanisms of Slurry RheologyOn a microscopic level, the rheology of the slurry hinges on interactions between its components. For example, in an anode slurry consisting of graphite, carbon black, PVDF binder, and NMP solvent, the particles' colloidal interactions dictate rheological behavior. These include van der Waals forces and steric hindrance from polymers, particularly between nanometer to micron-sized particles.Impact on Electrode CoatingThe link between rheology of the slurry and the coating process cannot be overstated. Slurries with higher viscosities encounter increased pressure and speed constraints during coating. Conversely, low-viscosity slurries risk spreading post-coating. The right balance involves controlling viscosity at the process's actual shear rate.Particle Interactions and Slurry StructureThe rheology of the slurry is shaped by particle interactions, with carbon black and graphite interacting distinctly within the polymer suspension. At varying shear rates, carbon black networks break into smaller aggregates due to hydrodynamic forces, altering viscosity. This behavior is reversible with shear reduction rebuilding the network.Polymer Influences in Slurry RheologyThe rheology of the slurry is also significantly impacted by polymer structures. The interaction between carbon black and PVDF, for example, varies with particle surfaces, affecting the layer thickness and inter-particle forces. In systems with graphite and CMC, adsorption levels, shear rates, and molecular weight all play key roles in viscosity changes.Slurry Challenges with High-Nickel MaterialsFor high-nickel materials, the rheology of the slurry faced challenges with PVDF binders undergoing dehydrofluorination due to residual base groups. This results in an irreversible gel-like network which complicates viscosity management. Techniques to alleviate this issue by adding solvents may not successfully reduce viscosity.Quote InquiryContact us

Revolutionizing Solid State Batteries with Solid electrolyte powder ionsImproving Solid Electrolyte Powder Ions for Better Battery SafetyExplore solid electrolyte powder ions for advancing safer and efficient batteries.Understanding Solid Electrolyte Powder Ions in Battery TechnologyThe pivotal variance between solid-state and liquid batteries lies in their electrolytes, where solid electrolyte powder ions play a crucial role. Liquid battery electrolytes predominantly consist of carbonate solvents combined with lithium salts. On the other hand, solid-state batteries utilize solid substances, leading to innovative battery designs.Solid Electrolyte Powder Ions: Categories and CharacteristicsSolid electrolyte powder ions are integral to ion conduction in solid-state batteries, substantially enhancing safety over traditional liquid lithium-ion batteries by eliminating PP/PE separators, which mitigates risks like lithium dendrite penetration. Key categories of solid electrolyte powder ions include oxides, sulfides, polymers, and halides.Each category of solid electrolyte powder ions has unique attributes. Oxide solid electrolytes, noted for their hardness, often pair with liquids to form semi-solid-state batteries. Sulfides, though moisture-sensitive, are considered promising for their high conductivity and softer texture. Polymer-based solid electrolyte powder ions suffer from low conductivity, whereas halides, still in research, offer promising ionic conductivity and voltage stability.Global Advances in Solid Electrolyte Powder IonsCountries like Japan and South Korea prioritize the sulfide route for developing solid electrolyte powder ions, while domestic enterprises often opt for oxides. This path enhances processing speed with semi-solid technologies. The pressure's influence on solid electrolyte powder ions’ performance can be profound, boosting ionic conductivity.Testing Solid Electrolyte Powder Ions: The SEMS1100 SystemYuanneng Technology’s SEMS1100 system marks a breakthrough in assessing solid electrolyte powder ions. It allows real-time measurements of ionic conductivity under pressure, vital for battery development.Solid Electrolyte Powder Ions in LPSC and LLZOSulfide solid electrolyte powder ions, like LPSC, exhibit impressive conductivity akin to liquid electrolytes. The SEMS1100 device reveals a decrease in EIS spectra with pressure increment, signifying better conductivity. Conversely, oxide electrolytes such as LLZO demonstrate lower conductivity due to poor particle-to-particle contact.Challenges and Future Directions for Solid Electrolyte Powder IonsDespite high compression generating excellent conductivity in sulfide solid electrolyte powder ions, major challenges persist, including environmental stability and interface compatibility. Yet, with continued research, the potential of solid electrolyte powder ions in revolutionizing battery technology remains promising.Conclusion: The Future of Solid Electrolyte Powder IonsIn conclusion, while oxide solid electrolyte powder ions often require combination with polymer or liquid counterparts, sulfide forms stand out for independent high conductivity after compression. Addressing existing issues could cement the role of solid electrolyte powder ions in daily battery technology, steering towards a safer energy future.Quote InquiryContact us

Exploring the Dynamics of Lithium battery slurry SuspensionsThe Role of Charged Particles in Lithium Battery SlurryIn lithium battery slurry suspensions, particle surfaces are always charged. This charge leads to the formation of an electric double layer on the particle surface, comprising an adsorption layer and a diffusion layer. The crucial aspect here is the zeta potential, which is the potential difference from the adsorption layer to the inside of the particles. A high zeta potential in lithium battery slurry allows particles to maintain sufficient distance to counteract van der Waals forces, thereby enhancing suspension stability. Conversely, a low zeta potential results in reduced inter-particle repulsion, leading to particle attraction and agglomeration.Factors Affecting Lithium Battery Slurry StabilityThe dispersed phase content, pH value, and inorganic salt concentration in the lithium battery slurry influence the thickness of the electric double layer. These factors alter the zeta potential and reduce electrostatic repulsion, affecting the slurry’s stability.Adsorption Mechanisms in Lithium Battery SlurryAdsorption plays a vital role in lithium battery slurry suspensions, defining how substances adhere to surfaces within the slurry. The surfactant’s adsorption mode, strength, and amount determine the interaction with dispersed particles. Within the lithium battery slurry, surfactants adhere to particle interfaces, creating a dense layer that increases steric hindrance among particles. This spatial stabilization enhances the anti-coalescence stability of the slurry.Influencing Surfactant Adsorption in Lithium Battery SlurryThe type and dosage of surfactant, along with molecular weight, system pH, salt concentration, and temperature, critically influence surfactant adsorption in lithium battery slurry suspensions. These factors determine the dispersion efficiency within the slurry system, significantly impacting performance.Quote InquiryContact us

Lithium Battery Ageing: Is Full Charge Dangerous?The manufacturing of lithium batteries encompasses three key stages: electrode production, cell packaging, and battery activation. Specifically, the activation process ensures full engagement of active substances with the electrolyte, promising stable electrochemical performance. This stage incorporates pre-charging, formation, and aging of lithium batteries, each step critical to maintaining optimal battery conditions.Understanding the Aging Process of Lithium BatteriesAging in lithium batteries involves storing them post-chemical charging and discharging. This step, conducted at room or elevated temperatures, is pivotal in ensuring performance stability. It facilitates full electrolyte penetration into electrode sheets, stabilizes the SEI film on the graphite negative electrode, and expedites the stabilization of electrochemical performance by accelerating potential side effects like gas production and electrolyte breakdown.Key Factors in Lithium Battery AgingState of Charge (SOC): The charge level of a lithium battery affects its aging rate and voltage drop. Tests under specific charging conditions are common.Storage Temperature: Temperature critically impacts the self-discharge rate and chemical reaction rate in lithium batteries.Aging Duration: Extended aging times, especially at high temperatures (e.g., 45°C for 7 days), are energy-intensive.Risks of Full Charge in Lithium Battery AgingChunpeng Zhao et al.'s research highlights the dangers associated with high SOC in lithium batteries. They created thermal shocks to induce explosions in lithium batteries, noting that higher SOC levels reduce time to explosion while increasing temperature and pressure outcomes. Specifically, a lithium battery at 100% SOC poses a significantly higher explosion risk, warranting careful evaluation of safety hazards during the activation process.Concluding ThoughtsThe process of lithium battery activation must balance operational processes with safety to prevent potential explosions. High-energy density in large batteries necessitates scrupulous attention to thermal safety, ensuring that fires and explosions are proactively avoided.Quote InquiryContact us