<2024> 4680 Battery Technology Development Trend and Outlook
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)Fast 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.
- Contents -
1.
4680 Cylindrical Battery Overview 12
1.1. Tesla Battery Day Analysis 14
1.2. Battery Day Summary and Key
Findings 15
1.3. Tesla Battery Cell Design 16
1.4. Tesla Battery Cell Manufacturing
Process 18
1.4.1. Coating 19
1.4.2. Winding 20
1.4.3. Assembly 20
1.4.4. Formation 20
1.5. Tesla Si-anode 21
1.6. Tesla Hi-Ni Cathode 22
1.7. Tesla Cell – Vehicle Integration
23
1.8. Tesla Cell Cost Improvement 24
1.9. Tesla 4680 Battery Development 25
1.9.1. Development History 25
1.9.2. Battery Specification 26
1.9.3. Battery-adopted Tesla EV 27
1.9.4. Battery Supplier 27
1.9.5. Battery Production Timing 28
1.10. 46xx Battery Roadmap 29
1.10.1. New 46xx Cell Design 29
1.10.2. New 46xx Cell Production 32
2.
4680 Battery Development Trend 34
2.1. Increased Demand for Cost
Reduction and Efficiency 34
2.2. Demanding Safety Requirements 34
2.3. Fast Charging as Future Trend 38
2.4. Battery Makers Competition for
Market Entrance 38
2.5. Tesla Development Trend 41
2.5.1. 4680 Sales Volume and
Production Capacity 41
2.5.2. 4680 Demand Calculation 42
2.6. Global OEMs’ Layout Acceleration
44
2.7. 46xx Battery Detailed
Specification by Maker 46
3.
4680 Battery Detailed Technology 54
3.1. Cathode 54
3.1.1. Application of Ultra High
Nickel 54
3.1.2. Establishment of Production
Capacity 56
3.1.3. Upgrade of Production
Technology 57
3.2. Anode 59
3.2.1. Silicon-based Development 59
3.2.2. Silicon-based Development
Timeline 60
3.2.3. Si-anode Modification 63
3.2.4. Acceleration of Si-anode
Industrialization 68
3.3. Other Battery Materials 70
3.3.1. SWCNT Conductive Material 70
3.3.2. Steel Battery Can 74
3.3.3. Al Battery Can 76
3.3.3.1. Al housing Cell Design
Concept 81
3.3.3.2. 46xx Large-size Cylindrical
Cell 83
3.3.3.3. 46xx Jelly Roll Concept 84
3.3.3.4. 46xx Jelly Roll Heat Transfer
and Distribution 84
3.3.3.5. 46xx Jelly Roll Heat
Simulation 85
3.3.3.6. 46xx Jelly Roll Cooling
Improvement 86
3.4. Production Process 88
3.4.1. 4680 Battery Production Process
Technology 88
3.4.2. 4680 Production Process
Differentiation 91
3.4.2.1. Dry Electrode Coating 91
3.4.2.2. Dry Process Examples 94
3.4.2.3. Electrode and Tab Integrated
Cutting 95
3.4.2.4. Difficulty of Laser Welding
97
3.4.2.5. Integrated Die casting and
CTC 99
4.
Tesla 4680 Battery Pack Disassembly 103
4.1. Overview 103
4.2. Battery Disassembly and Analysis
103
4.3. Tesla 4680 Battery Cell, Pack,
and Engineering Analysis 112
4.3.1. Tesla 4680 Battery Design Data
112
4.3.2. Pack Structure (Cell Direction)
122
4.3.3. Electricity Connection with
Each Cell 123
4.3.4. Suggested Pack Assembly Method
125
4.3.5. Model 3 Pack Analysis 126
4.3.5.1. Pack Analysis Result
(Summary) 126
4.3.5.2. Details of Heat Release 129
4.3.6. Model 3 Battery Current
Collector 131
5.
Tesla 4680 Battery Cell Disassembly and Characteristics 135
5.1. Summary 135
5.2. Overview 135
5.3. Previous Studies 136
5.4. Detailed Analysis 137
5.5. Specific Experiment 137
5.5.1. Test Cell Overview 137
5.5.2. Cell Disassembly and Substance
Extraction 138
5.5.3. Structure and Element Analysis
142
5.5.4. 3 Electrode Analysis 143
5.5.5. Electrical Characteristics 143
5.5.6. Thermal investigation· 145
5.6. Result and Consideration 145
5.6.1. Cell and Jelly roll Structure
145
5.6.2. Electrode Design 147
5.6.3. Material Characteristics 149
5.6.4. 3 Electrode Analysis 152
5.6.5. Capacity and Impedance Analysis
153
5.6.6. Similar OCV, DVA and ICA
Analysis 154
5.6.7. HPPC Analysis 156
5.6.8. Thermal Characteristics
Analysis 156
5.7. Conclusion 158
6.
Technologies for Success of 4680 Battery 163
6.1. Multi(all) Tab Technology 163
6.2. Tab Welding Technology 171
6.3. Cooling Technology 176
7.
4680 Battery Energy Density Improvement and Cost Down 183
7.1. Overview 183
7.2. Energy Density ↑/ Fast Charging
↑/ Cost ↓ 184
7.2.1. Blade Battery / High-Ni
Prismatic Battery Comparison 184
7.2.2. Increase of Fast Charging Rate
186
7.2.3. Production Improvement and Cost
Down with Dry Electrode (DBE) 188
7.3. High-Concentration Electrolyte
Adoption 191
7.3.1. Decrease of 4680 Electrolyte
Q’ty / GWh 191
7.3.2. High-Concentration Electrolyte
and LiFSI Addition 195
7.3.3. Fluorine FEC Addition 200
7.4. 4680 Electrolyte Major Players
202
8.
4680 Battery Heat Problem Prediction and Mitigation Solutions 204
8.1. Experiment Summary 204
8.2. Experiment Method 204
8.3. Heat Transfer Model Equation 206
8.4. Experiment Result and Discussion
207
8.5. Experiment Conclusion 210
9.
Cylindrical LIB Cell Design, Characteristics and Manufacturing 212
9.1. Overview 212
9.2. Experiment Material and Method
214
9.2.1. Cell Design 214
9.2.2. Cell Properties 217
9.2.3. Cell Energy Density 217
9.2.4. Cell Impedance 218
9.2.5. Cell Temperature 218
9.3. Experiment Result and
Consideration 219
9.3.1. Cylindrical LIB Cell Design 219
9.3.2. Jelly Roll Design 221
9.3.2.1. Geometry 221
9.3.3. Tab Design 223
9.3.4. Cell Properties 227
9.3.4.1. Cell Energy Density 227
9.3.4.2. Cell Resistance 228
9.3.4.3. Cell Thermal Behavior 229
9.3.5. Jelly Roll Manufacturing 231
9.4. Experiment Conclusion 234
10.
Cell size and Housing Material and their Influences of Tabless Cylindrical LIB
Cell 235
10.1. Overall Overview 235
10.2. Experiment 236
10.2.1. Reference cell 236
10.2.2. Cell Modeling 237
10.2.2.1. Cell Size and Geometric
Model 237
10.2.2.2. Jelly Roll Electrode Layer
237
10.2.2.3. Hollow core 237
10.2.2.4. Tabless Design 237
10.2.3. Cell Housing 238
10.2.4. Thermal – Electrical –
Electrochemical Framework 238
10.2.4.1. Boundary Conditions and Discretization
239
10.3. Experiment Result and Discussion
239
10.3.1. Energy Density 239
10.3.1.1. Influence of Cell Diameter
239
10.3.1.2. Influence of Cell Height 241
10.3.1.3. Influence of Housing
Material 241
10.3.2. Fast Charging Performance 242
10.3.2.1. Realization of Heat Transfer
Coefficient Control Algorithm 242
10.3.2.2. Influence of Cell Height and
Housing Material with Axial Cooling 243
10.3.2.3. Influence of Cell Diameter
and Housing Material with Axial Cooling 246
10.3.2.4. Influence of Tab Design and
Scaling of Series Resistance 250
10.3.2.5. Influence of Cell Size and
Housing Material on Fast Charging 252
10.4. Experiment Conclusion 253
11.
4680 Cell Maker and Car OEMs Current Status 256
11.1. Tesla 256
11.2. Panasonic 258
11.3. LGES 260
11.4. SDI 261
11.5. EVE 261
11.6. BAK 266
11.7. CATL 266
11.8. Guoxuan Hi-TECH 268
11.9. SVOLT 269
11.10. CALB 270
11.11. Envision AESC 271
11.12. LISHEN 273
11.13. Easpring 274
11.14. Kumyang 275
11.15. BMW 276
11.16. Rimac 280
12.
Tesla 4680 Battery Patent Analysis 281
12.1. Tabless Electrode Battery
(PTC/US2019/059691) 281
12.2. Tabless Energy Storage Devices
and their Manufacturing Methods (PTC/US2021/050992) 285
12.3. Dry Process Patent 1(Inclusion
of particulate nonfibrification binder: US11545666 B2) 294
12.4. Dry Process Patent 2
(Compositions and methods for passivation of electrode binders: US11545667 B2)
298
13.
4680 Battery Market Outlook 301
13.1. Overall Market Outlook 301
13.2. 4680 Major Materials Market
Outlook 306
13.2.1. Si-based Anode 306
13.2.2. Hi-Ni Ternary Cathode 310
13.2.3. LiFSI 312
13.2.4. Composite Copper Foil 314
13.2.5. PVDF Binder 316
13.2.6. CNT Conductor 316
13.2.7. Laser Welding Equipment 317
13.2.8. Housing CAN 318
13.2.9. Ni plated CAN 319
13.3. 4680 Demand Outlook and Capacity
Outlook 321
14.
Tesla 4680 Cell Production Outlook 325
14.1. 4680 Outlook by Consulting
Company 325
14.2. Tesla/BMW 4680 Demand Outlook
325
14.3. Tesla 4680 Cell for Cybertruck
Production Outlook 326
14.3.1. 4680 Giga Texas Production
Estimates 326
14.3.2. 4680 Cell Production Capacity
vs. Cybertruck Production Volume (Units) 327
14.3.3. 4680 Cell Annual Capacity vs.
Daily Production Volume 328
14.3.4. 4680 Cell Production Capacity
vs. Production Time Change Trend 328
14.3.5.
Tesla Giga Factory P/P Line Major Processes 329