Battery 4680 vs 2170

A 4680 battery is a cylindrical lithium-ion cell with a diameter of 46 millimeters (mm) and a height of 80 millimeters (mm).

The 4680 battery is a next-generation cylindrical lithium-ion battery designed by Tesla for electric vehicles.

(Source: Tesla Battery Day)

The 4680 battery is made up of several key components:

Electrodes:

• Cathode: There can be some variation here, but Tesla primarily uses a Lithium Nickel Manganese Cobalt (NCM) cathode chemistry, specifically NCM 811 in some of their current iterations. This cathode material offers high energy density for strong performance.
• Anode: The anode is typically made from graphite, a common choice in lithium-ion batteries due to its good electrical conductivity and ability to store lithium ions.

Separator: A thin, microporous membrane separates the anode and cathode. This allows ions to flow between the electrodes but prevents them from physically touching, which could cause a short circuit.

Electrolyte: This conductive solution carries lithium ions between the anode and cathode during charging and discharging. The specific electrolyte makeup is proprietary information, but it likely involves lithium salts dissolved in a solvent.

Canister: The 4680 uses a cylindrical metal casing to hold all the internal components.

Additional components: There are additional components that facilitate current collection, maintain structural integrity, and enhance safety. These may include current collectors, binders, and safety additives.

For a fair comparison, we’ll use commonly used performance parameters assuming the same active materials in both batteries.

Weight/Volume: A 2170 cylindrical battery weighs 68.64g and has a volume of 24.25cc. In comparison, the 4680 cylindrical battery weighs 352.44g and has a volume of 132.95cc. This translates to a volume and weight that are roughly 5-6 times greater for the 4680 battery.

Battery Capacity: The 2170 cylindrical battery has a capacity of approximately 18.12 Wh, while the 4680 boasts a capacity of around 100 Wh. This represents a more than 5-fold increase in capacity for a single 4680 cell compared to a 2170 cell.

Energy Density: The energy density by weight (Wh/kg) for the 2170 battery is 263.93, and its energy density by volume (Wh/L) is 747.05. The 4680 battery achieves energy densities of 282.36 Wh/kg and 752.15 Wh/L, respectively. While the improvement in volumetric energy density is minimal (586.85 Wh/L for 2170 vs. 590.74 Wh/L for 4680), the 4680 benefits from advancements like electrode-free tabs and dry processing technology, leading to a significant improvement in overall energy density.

Battery 4680 vs 2170 Specs

One of the main challenges with using large numbers of cylindrical batteries is the complexity of the Battery Management System (BMS) needed to monitor them accurately. Take the Model Y Long Range version for example. It requires approximately 4,416 21700 cylindrical batteries, each with a capacity of around 18 Wh. Currently, only a few car manufacturers (like Tesla) possess BMS systems precise enough to handle the monitoring of thousands of batteries simultaneously.

The 4680 large cylindrical battery significantly reduces the number of batteries required in a pack, thus simplifying BMS management. With a single cell boasting a capacity of roughly 100 Wh, a Model Y would only need around 800 4680 cells. This translates to an 81.88% reduction in the number of batteries that need monitoring compared to a pack using 21700 cells, drastically lowering the complexity of BMS management. This reduction in BMS complexity could promote the wider adoption of cylindrical batteries in electric vehicles.

Tesla aims to achieve significant cost reductions across various aspects of the 4680 battery, including cell design, production processes, and materials. According to their goals, the vehicle range will be increased by 54%, the battery cost per kWh will be reduced by 56%, and the investment cost will be reduced by 69% per GWh.

Battery Core Production: The 4680 tabless battery features a no-lug design, eliminating the need for tab installation or welding. This simplifies the manufacturing process by reducing the number of parts. Consequently, Tesla’s new battery production line will be 7 times faster, significantly improving production efficiency. Additionally, the investment cost per kilowatt-hour of production capacity will be reduced by 75%, creating favorable conditions for rapid production scale-up.

Positive and Negative Electrode Materials: High-nickel + silicon base materials are used. Nickel metal offers advantages in both specific capacity and cost compared to cobalt metal. Tesla promotes the development of cobalt-free cathodes by adopting a high-nickel cathode solution and utilizing new binders and conductive agents. This approach targets a 15% reduction in cathode material costs. In terms of negative electrode materials, Tesla utilizes a low-cost coated silicon negative electrode material, priced at around $1.2/kWh, which is more affordable than silicon-oxygen or silicon-carbon options. These material cost reductions translate to a 5% decrease in battery pack cost per kWh and ultimately contribute to a 20% increase in electric vehicle cruising range.

Complete Vehicle Manufacturing: Tesla’s innovative CTC (Cell-to-Chassis) technology optimizes interior space utilization. They have developed a new body structure that integrates the battery pack as a structural element, eliminating the need for separate battery pack components. This integration saves cost and space while improving the energy density at the battery pack level. Additionally, the overall number of structural parts required for the vehicle is reduced, leading to lower costs and weight. Tesla’s CTC technology is expected to reduce body weight by 10%, increase battery life by 14%, and decrease the number of parts by 370.

(Source: Tesla Battery Day)

BMW has announced it will be the first automaker to use cylindrical batteries in its ‘next generation’ models starting in 2025. The company awarded battery cell production contracts worth over 10 billion euros to CATL and EVE (Everview Lithium Energy).

NIO plans to build its first battery factory in Hefei to produce large cylindrical batteries, similar to Tesla’s 4680 format. The planned production capacity is 40 GWh, enough for batteries in 400,000 electric vehicles.

In October 2021, Panasonic developed the 4680 large cylindrical battery and invested 80 billion yen to build two new production lines in their Wakayama factory, Japan. These lines have a combined capacity of 10 GWh, targeted for use in 150,000 electric vehicles.

LG New Energy announced a new 4680 battery production line at its Chungju factory in South Korea (June 2022) to supply Tesla. With a planned capacity of 9 GWh, production is expected to begin in the second half of 2023.

Samsung SDI has established a 4680 battery test production line in Cheonan, South Korea. If the test goes well, they plan to build a 4680 battery mass production line in Malaysia next year, with a planned production capacity of 8-12GWh, to supply Tesla.

EVE Energy plans a large cylindrical production capacity of 61GWh+. In March 2022, they announced a cylindrical battery factory in Hungary to supply BMW. The first system product equipped with 46 series large cylindrical batteries successfully rolled off the production line in August. The company expects to generate 20GWh in 2023, with customers including BMW and Universiade. As of November 23, they have secured orders for Series 46 large cylinders totaling 486GWh in the next five years.

BAK announced on January 28, 2023 that it has signed a strategic cooperation agreement with Changzhou City, Jiangsu Province, and will spend 13 billion yuan to build its large cylindrical battery production line in Changzhou. After completion, the production capacity will reach 30 GWh.

(Source: SNEResearch, Offical Websites)