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The determination of low battery capacity (low capacity) for battery cells is based on a straightforward comparison between the post-formation (post-charging/discharging cycle) capacity and the designed capacity value. If the capacity measured after the formation process is lower than the designed value, the first response should be to confirm whether there are errors in the formation process settings (such as discharge current, charging time, cut-off voltage, and formation temperature). ①If the formation step settings are correct, it is necessary to change the testing point and re-perform the formation process on the battery cell to check if there are issues with the formation equipment or channels. ②Assuming no abnormalities are found in the formation data after changing the equipment, then the original equipment is likely problematic. ③If the re-test still shows low capacity, it can be confirmed that the low-capacity issue truly exists. After confirming the existence of low capacity, it is necessary to further determine the frequency and severity of the low-capacity occurrences to grasp the actual situation of low capacity from an overall perspective. This requires a more systematic approach. Before conducting a systematic analysis, it is advisable to first disassemble the re-charged low-capacity battery cells to inspect the interface. If no issues are found, it is likely due to insufficient positive electrode coating weight or inadequate design margin. If there are interface problems, it may be due to other issues in the manufacturing process or design. Next, we will investigate the causes of low capacity from the design end and the process manufacturing end. I. Design End Material system compatibility: In particular, the compatibility between the negative electrode and electrolyte has a significant impact on battery cell capacity. For newly introduced negative electrodes or electrolytes, if repeated tests show that each battery cell experiences lithium plating and low capacity, there is a high likelihood of material mismatch. The reasons for mismatch may include: ①Inadequate density, thickness, or instability of the SEI (Solid Electrolyte Interphase) film formed during formation; ②Possible delamination of the graphite layer caused by PC (propylene carbonate) in the electrolyte; ③Excessively high designed areal density or compaction density, making the battery cell unable to adapt to high-rate charging and discharging. Adequacy of capacity design margin: ①Starting from the gravimetric capacity of the positive electrode material: Due to errors in positive/negative electrode coating, formation cabinet accuracy, and adhesive effects on capacity, a certain capacity margin must be reserved during design. For new materials, accurate assessment of the gravimetric capacity of the positive electrode in the specific system is crucial. The same positive electrode material may not exhibit the same gravimetric capacity when paired with different negative ...

What is COV The COV (Coefficient of Variation) in lithium-ion battery coating is a statistical indicator used to quantify the consistency of the coating process. It is calculated using the formula: COV = (Standard Deviation σ / Mean) × 100%. By eliminating differences in dimensions, this indicator reflects the dispersion degree of the dataset. A lower COV value indicates better coating uniformity. How to Evaluate Coating Quality Using COV Evaluation of Coating Surface Density Consistency The COV directly reflects the degree of fluctuation in coating surface density. For example, a COV of 0.5% for coating surface density indicates that the standard deviation of the data is 0.5% of the mean value. Industry standards are as follows: COV ≤ 0.3%: Extremely high surface density consistency. 0.3% < COV < 0.5%: Current mainstream level. COV > 0.5%: Process optimization is required. This indicator directly impacts cell capacity design. For instance, with a COV of 0.5%, a 3σ corresponds to a fluctuation of 1.5%, and the minimum cell capacity design needs to be set at 98.5% of the mean value. Analysis of AB Surface Coating Uniformity By using in-situ resistance testing methods (such as the BER2500 device), the resistance of the A-side, B-side, and total through-resistance of the electrode are measured respectively, and the COV value of each resistance is calculated. The larger the COV, the more uneven the distribution of the conductive network in the coating. For example, in a double-sided coating process, if there is a significant difference in the COV of AB surface resistance, it may be due to uneven distribution of conductive agents caused by slurry sedimentation or different drying rates, which may further lead to lithium plating or reduced cycle life of the battery. Optimization Directions for Process Parameters Slurry Stability: Changes in slurry viscosity and solid content directly affect the coating COV. It is necessary to ensure that the slurry has no sedimentation and stable fluidity. Drying Control: Excessively high or low temperatures can cause coating cracks or incomplete drying, affecting surface density consistency. Equipment Precision: Slit extrusion coating technology is more suitable for reducing COV due to its closed system and high-precision control. Precautions Sensitivity to Extreme Values: COV is susceptible to outliers. It is necessary to combine data cleaning or supplement other indicators (such as CPK) for comprehensive evaluation. Multidimensional Verification: In addition to surface density, it is recommended to combine COV values of resistance, thickness, and other parameters to comprehensively evaluate coating quality.

This is mainly due to three reasons: differences in material characteristics between the cathode and anode, varying process effects and performance requirements, and different temperature sensitivities of binders. 1.Differences in Material Characteristics Between Cathode and Anode The cathode materials (such as LiFePO4, NCM) are hard and poorly conductive, and hot rolling can effectively enhance the compaction effect: the high hardness of particles leads to high compaction resistance (the compaction resistance of the cathode is four times that of the anode), and hot rolling softens the PVDF binder to enhance the bonding force between the active material and the current collector. Hot rolling can reduce pole piece rebound by about 50%, reduce rolling force by up to 62% (depending on the specific material system and process capabilities), and simultaneously improve the distribution of conductive agents, enhancing electron conduction efficiency. The anode's graphite is low in hardness and prone to plastic deformation, but excessive compaction can easily lead to particle crushing: secondary cold rolling adjusts thickness and pore structure in stages, reducing stress concentration and avoiding particle fracture caused by a single high pressure. Secondary rolling can make the pore distribution more uniform, reducing the expansion rate from 5.00% to 4.47% after cycling and improving cycle stability. 2.Process Effects and Performance Requirements Optimization of cathode hot rolling: Hot rolling at 100°C significantly reduces pole piece resistance (by 2.1%) and thickness rebound rate (by 50%), while increasing the peak peel strength. Hot rolling requires less rolling force when thinning pole pieces, and thickness uniformity is easier to control (uniformity of roller surface temperature is required to be high, as it deteriorates at 120°C). Advantages of anode secondary cold rolling: Secondary cold rolling gradually increases compaction density, avoiding a decrease in peel strength caused by a single high pressure (e.g., peel strength after one-time rolling is 0.298N vs. remaining stable at 0.298N after secondary rolling). The lateral and longitudinal elongation rates stabilize at 0.27% and 1.17%, respectively, reducing the risk of pole piece cracking. 3.Binder and Temperature Sensitivity The cathode's PVDF maintains good viscosity at high temperatures (40~150°C), and hot rolling promotes crosslinking with active substances, enhancing bonding strength. The anode's aqueous binder (such as CMC/SBR) is heat-sensitive, and high temperatures may cause degradation. Cold rolling maintains chemical stability, avoiding a decrease in peel strength. Due to the cathode's hardness and poor conductivity, hot rolling is required to improve compaction and electrical performance; anode secondary cold rolling balances the need for plastic deformation with structural integrity, avoiding particle crushing and stabilizing peel strength. The differences in processes between the ...

What are solid-state batteries? Solid-state batteries are a type of battery that uses solid electrolytes to replace traditional liquid or gel-type electrolytes. Compared to conventional lithium-ion batteries, solid-state batteries have a more stable structure, offering higher energy density, safer performance, and faster charging speed. The main problems with solid-state batteries: Technical Aspects Low ionic conductivity: The strong interaction between ions and high migration energy barriers in solid electrolytes result in lower ionic conductivity compared to liquid electrolytes, leading to slow charging and discharging rates and rapid capacity fading. Lithium dendrite growth: Even with solid electrolytes of high mechanical strength, it is difficult to completely inhibit the growth of lithium dendrites, which can form on the surface of the negative electrode and even penetrate through the solid electrolyte, causing battery short circuits. Solid-solid interface issues: The solid-solid interface in solid-state batteries has a small contact area, and volume changes during electrode charging and discharging can disrupt the interface structure, worsening contact, increasing interface impedance, and potentially causing chemical reactions to form unstable interface layers. Mechanical performance challenges: Solid materials in solid-state batteries are more prone to cracking when subjected to mechanical stress, such as during battery assembly or during vibrations or collisions in use, affecting battery performance and safety. Poor low-temperature performance: Solid-state batteries may experience more pronounced performance degradation in low-temperature environments, affecting their use in cold regions. Cost Aspects High material costs: Expensive materials such as lithium metal and special ceramic electrolytes, including high-priced lithium sulfide, are typically used, resulting in costs significantly higher than those of liquid lithium batteries. High manufacturing costs: The production process is complex, requiring precision processes and equipment, such as high-density stacking and high-precision electrolyte coating, as well as special production environments, with low production efficiency, leading to higher manufacturing costs. Environmental and Recycling Aspects Resource and energy consumption issues: From raw material extraction, processing, to manufacturing, significant natural resources and energy are consumed. The mining and refining of new materials can damage the environment, and the high energy consumption during production increases carbon emissions. Recycling challenges: The recycling and disposal of discarded solid-state batteries pose challenges. Their internal structures are complex, containing multiple metals and chemicals. Improper recycling can pollute the environment, and recycling technologies and processes are immature and costly.

February 10, 2025, XiaMen: As the festive atmosphere of the Chinese New Year gradually fades, all employees of TOB NEW ENERGY officially concluded their Spring Festival holidays today (February 10) and returned to work with full enthusiasm and high morale, embarking on a new year's journey of striving! At 10:00 a.m., TOB NEW ENERGY headquarters and branches across various locations simultaneously held simple yet warm commencement ceremonies. Mr. Huang, representing the company's management, extended New Year greetings and best wishes to all employees, thanking everyone for their hard work and outstanding contributions over the past year. Mr. Huang also encouraged everyone to continue striving for excellence in the new year, aiming high and working together to achieve the company's annual goals! Mr. Huang emphasized in the speech: 2025 is a crucial year for TOB NEW ENERGY to achieve its strategic goals, with both opportunities and challenges ahead. All employees must quickly adjust their mindset, refocus, and dedicate themselves to the new year's work with even greater enthusiasm, higher morale, and a more pragmatic approach, contributing to the company's high-quality development! Mr. Huang also pointed out: In the new year, the company will adhere to its development strategy, continue to increase investments in R&D, and continuously enhance core competitiveness. The company aims to provide customers with higher-quality products and services, create broader development platforms for employees, and generate greater value for society! Following the commencement ceremony, employees from various departments swiftly engaged in their work with a focused and orderly approach, embracing the challenges of the new year with a spirited attitude. Everyone expressed that in the new year, they will face challenges with even greater determination and a more pragmatic style, striving together to achieve the company's annual goals and jointly writing a new chapter in TOB NEW ENERGY's development! TOB NEW ENERGY, as a leading enterprise in the battery production line solutions, has always adhered to its quality first, service supreme company philosophy and is committed to becoming an industry leader and promoting the company's mission of sustainable development. With the collective efforts of all employees, TOB NEW ENERGY is confident in achieving even greater success and glory in 2025!

Dear Valued Clients, As the Chinese New Year approaches, we would like to inform you that our company will be observing the holiday from January 25th to February 9th. During this period, our offices will be closed, and regular business operations will resume on February 10th. We sincerely appreciate your continued support and trust in our services. Wishing you a joyful and prosperous Chinese New Year! Emergency Contact: Tel : +86-18120715609 Email : tob.amy@tobmachine.com

On January 14, 2025, TOB NEW ENERGY organized a fire drill. Process Description: At 4 PM, a warehouse clerk discovered a fire in the warehouse. The fire was intense, prompting immediate alerting actions. The clerk organized the evacuation of warehouse staff and notified the general manager. The general manager swiftly mobilized all emergency response teams into position. (1) The warehouse supervisor secured the scene and brought along the emergency medical kit. (2) The emergency contact dialed 119 to report the fire. (3) The safety officer notified all relevant contingency plans. The main content of this fire drll was to simulate a warehouse fire and demonstrate how employees could self-rescue and evacuate after a fire breaks out, familiarize themselves with the use of fire-fighting equipment, and learn how to extinguish initial-stage fires. During the drill, employees covered their mouths with wet towels or hands, bent over, and quickly and orderly evacuated from the warehouse to the emergency assembly point. At the same time, they gained knowledge about fire safety and the use of fire extinguishers, and everyone personally operated a fire extinguisher.

TOB NEW ENERGY to All Employees and Valued Customers: As another year draws to a close and the holiday season is upon us, TOB NEW ENERGY would like to express our sincere gratitude to all our employees for their hard work and dedication throughout the year. We would also like to thank our valued customers for their continued support and trust. This past year has been filled with both challenges and triumphs. Through the collective efforts of our employees, we have achieved remarkable results and witnessed steady growth across all business lines. This success is a testament to the hard work and dedication of every individual in our company, as well as the unwavering support of our customers. On this joyous occasion, TOB NEW ENERGY TEAM extends our warmest wishes for a Merry Christmas and a Happy New Year! May the coming year bring you health, happiness, and prosperity. Looking ahead, we are filled with optimism! We remain committed to our core values of “Top of Best, Top of Battery”, and we will continue to put our customers first by consistently improving our battery machine and battery production line solution. We will invest heavily in research and development to drive innovation and provide our customers with even better services in solid-state battery solutions, sodium-ion battery solutions, supercapacitor solutions, and lithium-ion battery production line solutions, etc. We will further strengthen our team by fostering a high-performing and highly skilled workforce. Once again, thank you for your continued support. Wishing you a joyous holiday season and a prosperous New Year! TOB NEW ENERGY TEAM December 24, 2024