<2024> 4680 배터리 기술 개발 동향 및 전망

Tesla acquired Maxwell Technologies for the dry battery electrode process (DBE) used in the production of large cylindrical batteries like the 4680. The dry electrode process is characterized by low energy requirements for drying, a smaller factory footprint for the drying process, and lower production costs. If the dry coating process is applied to both electrodes, it could lead to significant cost reductions, creating a win-win situation for EV manufacturers and production companies. The dry electrode process is one of the manufacturing technologies employed by Tesla for the 4680 battery, and with the implementation of various technologies for 4680 production, an overall cost reduction of 56% is anticipated.

Tesla is currently producing 4680 cells with dry-coated electrodes at the Gigafactory in Texas Austin, where Model Y and Cybertruck are being manufactured. According to available information, Tesla has not yet completed the dry coating process on the scale required to rapidly produce 4680 cells to meet production targets. However, several companies, including Panasonic, LG, CATL, EVE, BAK, SVOLT, and others, have entered the development and mass production of 4680 cells. The 4680 trend is gaining momentum globally, with announcements from BMW, Daimler, Apple, Lucid, Rivian, Xiaopeng, NIO, FAW, JAC Motors, and others regarding the adoption of 4680 batteries.

According to the forecasts from SNE Research, the demand for xEV 4680 cells is projected to be approximately 72 GWh by the year 2025 and around 650 GWh by the year 2030. For Tesla, it is estimated to be around 80 GWh by the year 2025, for BMW around 59 GWh, and for other companies, approximately 44 GWh by the year 2025.

Despite the challenges of the dry coating process, there are several reasons for the adoption of the 4680 cells. Below are listed the outstanding advantages of the 4680 cells:

• (1)High energy density: The capacity of the 4680 cells is five times that of the 2170 cells, with only a change in external dimensions. Additionally, by utilizing a Si/C (Silicon/Carbon) anode, it is possible to achieve a 10% increase in energy density. Furthermore, with the use of a Si/C anode, the energy density can be further increased by up to 20%, reaching beyond 300 Wh/kg.
• (2)Safety: The "cylindrical" design is considered the most robust solution for thermal runaway, a critical safety issue associated with heat propagation within battery packs. Recent battery incidents have all been attributed to thermal runaway in specific battery cells within the pack, leading to the generation of a significant amount of heat that, in turn, heats up surrounding battery cells, resulting in the propagation of thermal runaway.

However, cylindrical batteries have a smaller cell capacity, and the energy released due to thermal runaway in a single battery is lower, reducing the likelihood of propagation compared to prismatic and pouch-shaped batteries. The curvature of the cylindrical design somewhat limits the heat transfer between batteries. In other words, even when cylindrical batteries are in complete contact due to their curved surfaces, there is still a significant gap, which somewhat restricts the heat transfer between batteries.

• (3)Rapid charging performance: The 4680 battery undergoes structural changes to enhance its charging speed, adapting to the high-speed charging requirements of the material system. Additionally, it incorporates an "All flag" design, further contributing to the acceleration of charging speeds.

(4)High production efficiency -> Low cost

Cylindrical batteries were the first commercially available lithium-ion batteries and have the most mature production processes. This is reflected in higher assembly efficiency compared to prismatic and pouch-shaped batteries. While the current production efficiency of the 4680 is unknown, the characteristics of cylindrical batteries, with their concentric winding design, determine the production speed. Despite larger cylindrical batteries having a lower production speed than smaller ones, they are still much faster than prismatic and pouch-shaped batteries. The production rate for 1865/2170 batteries is typically around 200PPM (200 batteries /minute). Meanwhile, for prismatic batteries with a capacity below 200Ah, the rate is around 10-12PPM, and for larger prismatic batteries with a capacity exceeding 200Ah, it's around 10PPM. The production efficiency of pouch-shaped batteries is even lower.

(5)Scaling up -> Reduced BMS complexity

For Tesla, the predominantly smaller capacity of cylindrical battery cells meant that achieving specific power performance required an enormous total number of cells. For instance, 7000+ cells of the 18650 type or 4000+ cells of the 2170 type were needed. This high cell count posed significant challenges in terms of thermal management for the battery system. Consequently, many automakers were discouraged from adopting cylindrical batteries. However, with the advent of the 4680 era, the required number of battery cells has decreased to 960-1360 cells. The reduced cell count implies improved space utilization in the pack and a substantial simplification of the required Battery Management System (BMS), addressing issues related to heat dissipation in large cylindrical batteries.

In this report, SNE Research systematically organizes information from various sources, including presentations from each company related to the 4680, scattered data from disassembly and performance tests, and reviews of key papers. Through this comprehensive approach, the report analyzes the practical effects and performance improvements of the 4680 introduction. Furthermore, by referencing data from external research institutions, our report aims to assist readers in understanding the outlook and scale of the large cylindrical battery market.

Additionally, we provides an overview of the current status and key products of 4680 manufacturers. It also highlights the scale of Gigafactory facilities and indicates the correlation between the production volume and quantity of Cybertruck, offering intriguing insights into the manufacturability of the 4680. The goal is to provide comprehensive insights to researchers and individuals interested in this field.

The Strong Point of this report is as below:

• 1. Summarizing the developmental trends and information related to the 4680 for an overall understanding and ease of comprehension.
• 2. In-depth analysis and summarization of the disassembly reports for 4680 cells and packs to enhance understanding.
• 3. Assessing the market and production outlook for 4680 batteries to understand market size and growth rates.
• 4. Detailed analysis of materials and technologies applied to the 4680 through the examination of academic papers.

Table of Contents

1. 4680 Cylindrical Battery Overview

• 1.1. Tesla Battery Day Analysis
• 1.2. Battery Day Summary and Key Findings
• 1.3. Tesla Battery Cell Design
• 1.4. Tesla Battery Cell Manufacturing Process
  • 1.4.1. Coating
  • 1.4.2. Winding
  • 1.4.3. Assembly
  • 1.4.4. Formation
• 1.5. Tesla Si-anode
• 1.6. Tesla Hi-Ni Cathode
• 1.7. Tesla Cell - Vehicle Integration
• 1.8. Tesla Cell Cost Improvement
• 1.9. Tesla 4680 Battery Development
  • 1.9.1. Development History
  • 1.9.2. Battery Specification
  • 1.9.3. Battery-adopted Tesla EV
  • 1.9.4. Battery Supplier
  • 1.9.5. Battery Production Timing
• 1.10. 46xx Battery Roadmap
  • 1.10.1. New 46xx Cell Design
  • 1.10.2. New 46xx Cell Production

2. 4680 Battery Development Trend

• 2.1. Increased Demand for Cost Reduction and Efficiency
• 2.2. Demanding Safety Requirements
• 2.3. Fast Charing as Future Trend
• 2.4. Battery Makers Competition for Market Entrance
• 2.5. Tesla Development Trend
  • 2.5.1. 4680 Sales Volume and Production Capacity
  • 2.5.2. 4680 Demand Calculation
• 2.6. Global OEMs' Layout Acceleration
• 2.7. 46xx Battery Detailed Specification by Maker

3. 4680 Battery Detailed Technology

• 3.1. Cathode
  • 3.1.1. Application of Ultra High Nickel
  • 3.1.2. Establishment of Production Capacity
  • 3.1.3. Upgrade of Production Technology
• 3.2. Anode
  • 3.2.1. Silicon-based Development
  • 3.2.2. Silicon-based Development Timeline
  • 3.2.3. Si-anode Modification
  • 3.2.4. Acceleration of Si-anode Industrialization
• 3.3. Other Battery Materials
  • 3.3.1. SWCNT Conductive Material
  • 3.3.2. Steel Battery Can
  • 3.3.3. Al Battery Can
    • 3.3.3.1. Al housing Cell Design Concept
    • 3.3.3.2. 46xx Large-size Cylindrical Cell
    • 3.3.3.3. 46xx Jelly Roll Concept
    • 3.3.3.4. 46xx Jelly Roll Heat Transfer and Distribution
    • 3.3.3.5. 46xx Jelly Roll Heat Simulation
    • 3.3.3.6. 46xx Jelly Roll Cooling Improvement
• 3.4. Production Process
  • 3.4.1. 4680 Battery Production Process Technology
  • 3.4.2. 4680 Production Process Differentiation
    • 3.4.2.1. Dry Electrode Coating
    • 3.4.2.2. Dry Process Examples
    • 3.4.2.3. Electrode and Tab Integrated Cutting
    • 3.4.2.4. Difficulty of Laser Welding
    • 3.4.2.5. Integrated Die casting and CTC

4. Tesla 4680 Battery Pack Disassembly

• 4.1. Overview
• 4.2. Battery Disassembly and Analysis
• 4.3. Tesla 4680 Battery Cell, Pack, and Engineering Analysis
  • 4.3.1. Tesla 4680 Battery Design Data
  • 4.3.2. Pack Structure (Cell Direction)
  • 4.3.3. Electricity Connection with Each Cell
  • 4.3.4. Suggested Pack Assembly Method
  • 4.3.5. Model 3 Pack Analysis
    • 4.3.5.1. Pack Analysis Result (Summary)
    • 4.3.5.2. Details of Heat Release
  • 4.3.6. Model 3 Battery Current Collector

5. Tesla 4680 Battery Cell Disassembly and Characteristics

• 5.1. Summary
• 5.2. Overview
• 5.3. Previous Studies
• 5.4. Detailed Analysis
• 5.5. Specific Experiment
  • 5.5.1. Test Cell Overview
  • 5.5.2. Cell Disassembly and Substance Extraction
  • 5.5.3. Structure and Element Analysis
  • 5.5.4. 3 Electrode Analysis
  • 5.5.5. Electrical Characteristics
  • 5.5.6. Thermal investigation
• 5.6. Result and Consideration
  • 5.6.1. Cell and Jelly roll Structure
  • 5.6.2. Electrode Design
  • 5.6.3. Material Characteristics
  • 5.6.4. 3 Electrode Analysis
  • 5.6.5. Capacity and Impedance Analysis
  • 5.6.6. Similar OCV, DVA and ICA Analysis
  • 5.6.7. HPPC Analysis
  • 5.6.8. Thermal Characteristics Analysis
• 5.7. Conclusion

6. Technologies for Success of 4680 Battery

• 6.1. Multi(all) Tab Technology
• 6.2. Tab Welding Technology
• 6.3. Cooling Technology

7. 4680 Battery Energy Density Improvement and Cost Down

• 7.1. Overview
• 7.2. Energy Density (up arrow)/ Fast Charging (up arrow)/ Cost (down arrow)
  • 7.2.1. Blade Battery / High-Ni Prismatic Battery Comparison
  • 7.2.2. Increase of Fast Charging Rate
  • 7.2.3. Production Improvement and Cost Down with Dry Electrode (DBE)
• 7.3. High-Concentration Electrolyte Adoption
  • 7.3.1. Decrease of 4680 Electrolyte Q'ty / GWh
  • 7.3.2. High-Concentration Electrolyte and LiFSI Addition
  • 7.3.3. Fluorine FEC Addition
• 7.4. 4680 Electrolyte Major Players

8. 4680 Battery Heat Problem Prediction and Mitigation Solutions

• 8.1. Experiment Summary
• 8.2. Experiment Method
• 8.3. Heat Transfer Model Equation
• 8.4. Experiment Result and Discussion
• 8.5. Experiment Conclusion

9. Cylindrical LIB Cell Design, Characteristics and Manufacturing

• 9.1. Overview
• 9.2. Experiment Material and Method
  • 9.2.1. Cell Design
  • 9.2.2. Cell Properties
  • 9.2.3. Cell Energy Density
  • 9.2.4. Cell Impedance
  • 9.2.5. Cell Temperature
• 9.3. Experiment Result and Consideration
  • 9.3.1. Cylindrical LIB Cell Design
  • 9.3.2. Jelly Roll Design
    • 9.3.2.1. Geometry
  • 9.3.3. Tab Design
  • 9.3.4. Cell Properties
    • 9.3.4.1. Cell Energy Density
    • 9.3.4.2. Cell Resistance
    • 9.3.4.3. Cell Thermal Behavior
  • 9.3.5. Jelly Roll Manufacturing
• 9.4. Experiment Conclusion

10. Cell size and Housing Material and their Influences of Tabless Cylindrical LIB Cell

• 10.1. Overall Overview
• 10.2. Experiment
  • 10.2.1. Reference cell
  • 10.2.2. Cell Modeling
    • 10.2.2.1. Cell Size and Geometric Model
    • 10.2.2.2. Jelly Roll Electrode Layer
    • 10.2.2.3. Hollow core
    • 10.2.2.4. Tabless Design
  • 10.2.3. Cell Housing
  • 10.2.4. Thermal - Electrical - Electrochemical Framework
    • 10.2.4.1. Boundary Conditions and Discretization
• 10.3. Experiment Result and Discussion
  • 10.3.1. Energy Density
    • 10.3.1.1. Influence of Cell Diameter
    • 10.3.1.2. Influence of Cell Height
    • 10.3.1.3. Influence of Housing Material
  • 10.3.2. Fast Charging Performance
    • 10.3.2.1. Realization of Heat Transfer Coefficient Control Algorithm
    • 10.3.2.2. Influence of Cell Height and Housing Material with Axial Cooling
    • 10.3.2.3. Influence of Cell Diameter and Housing Material with Axial Cooling
    • 10.3.2.4. Influence of Tab Design and Scaling of Series Resistance
    • 10.3.2.5. Influence of Cell Size and Housing Material on Fast Charging
• 10.4. Experiment Conclusion

11. 4680 Cell Maker and Car OEMs Current Status

• 11.1. Tesla
• 11.2. Panasonic
• 11.3. LGES
• 11.4. SDI
• 11.5. EVE
• 11.6. BAK
• 11.7. CATL
• 11.8. Guoxuan Hi-TECH
• 11.9. SVOLT
• 11.10. CALB
• 11.11. Envision AESC
• 11.12. LISHEN
• 11.13. Easpring
• 11.14. Kumyang
• 11.15. BMW
• 11.16. Rimac

12. Tesla 4680 Battery Patent Analysis

• 12.1. Tabless Electrode Battery (PTC/US2019/059691)
• 12.2. Tabless Energy Storage Devices and their Manufacturing Methods (PTC/US2021/050992)
• 12.3. Dry Process Patent 1(Inclusion of particulate nonfibrification binder: US11545666 B2)
• 12.4. Dry Process Patent 2 (Compositions and methods for passivation of electrode binders: US11545667 B2)

13. 4680 Battery Market Outlook

• 13.1. Overall Market Outlook
• 13.2. 4680 Major Materials Market Outlook
  • 13.2.1. Si-based Anode
  • 13.2.2. Hi-Ni Ternary Cathode
  • 13.2.3. LiFSI
  • 13.2.4. Composite Copper Foil
  • 13.2.5. PVDF Binder
  • 13.2.6. CNT Conductor
  • 13.2.7. Laser Welding Equipment
  • 13.2.8. Housing CAN
  • 13.2.9. Ni plated CAN
• 13.3. 4680 Demand Outlook and Capacity Outlook

14. Tesla 4680 Cell Production Outlook

• 14.1. 4680 Outlook by Consulting Company
• 14.2. Tesla/BMW 4680 Demand Outlook
• 14.3. Tesla 4680 Cell for Cybertruck Production Outlook
  • 14.3.1. 4680 Giga Texas Production Estimates
  • 14.3.2. 4680 Cell Production Capacity vs. Cybertruck Production Volume (Units)
  • 14.3.3. 4680 Cell Annual Capacity vs. Daily Production Volume
  • 14.3.4. 4680 Cell Production Capacity vs. Production Time Change Trend
  • 14.3.5. Tesla Giga Factory P/P Line Major Processes