Cylindrical 21700 High-Energy Cell
FEB 68E
Cylindrical 21700 cell delivering 6.5 Ah capacity, 312 Wh/kg energy density and 13 A maximum discharge rate.
Overview
The FEB 68E is a high-energy Li-ion cylindrical 21700 cell designed for applications that demand high energy density and extended runtime. Released in 2025 and with the manufacturer based in China, this cylindrical 21700 cell delivers 6.5 Ah capacity and 23.4 Wh of energy at a nominal voltage of 3.6 V, with a maximum continuous discharge capability of 13 A, making it suitable for applications with moderate power requirements. A gravimetric energy density of 312 Wh/kg puts it at the upper end of the library. The silicon-bearing anode contributes to that energy density.
Key Features
Discharge rate: 13 A continuous (2.0 C)
Energy density: 312 Wh/kg
Power density: 624 W/kg
Capacity: 6.5 Ah nominal capacity
Applications: aviation, e-mobility, drones
Technical Specifications from the Manufacturer
Parameter
Manufacturer
FEB
Model
21700-68E
Type
Li-ion
Form factor
Cylindrical 21700
Country of origin
China
Release year
2025
Nominal voltage
3.6
Energy capacity [Wh]
23.4
Capacity [Ah]
6.5
Gravimetric energy density [Wh/kg]
312
Gravimetric power density [W/kg]
624
Max continuous discharge [A]
13
Volume [cm³]
26.1191
Mass [g]
75
Positive electrode (cathode)
Ni-based
Negative electrode (anode)
Graphite/Si additive
Value
Applications & Use‑Cases
The FEB 68E is well suited to the following applications due to its 21700 format and high energy density performance.
Aviation: Requires high specific energy for extended flight duration, high power-to-weight ratio for climb performance, and reliable operation across wide temperature ranges at altitude.
E-Mobility: Requires balanced energy and power density for range and acceleration, high cycle life for daily use, and robust calendar life to ensure long-term reliability.
Drones: Demands high gravimetric power density for thrust and payload capacity, rapid current response for flight control, and stable voltage delivery across dynamic flight profiles.
General Applications: Suitable for applications requiring reliable lithium-ion performance with proven cycle life, consistent capacity delivery, and operational safety across diverse use cases.
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Performance & Model Data
Below are modelled performance metrics for the FEB 68E across key indicators, including constant current behaviour, rate capability, temperature dependence, and available power under representative drive cycle conditions.
Constant Current Voltage
Access FEB 68E constant-current discharge curves in Voltt to size your pack against the voltage window your system actually needs. (Chart shown is illustrative, not 68E data.)
Constant Current Temperature
Access FEB 68E thermal discharge data in Voltt to specify cooling and cell spacing before you commit to a pack layout. (Chart shown is illustrative, not 68E data.)
Pulse Power Behaviour
Access FEB 68E pulse power maps in Voltt to set peak current limits and parallel count for your worst-case load. (Chart shown is illustrative, not 68E data.)
Dynamic Profile Response
Access FEB 68E mission profile simulations in Voltt to prove the pack holds up over a real duty cycle before you build it. (Chart shown is illustrative, not 68E data.)
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Case Studies
See how we helped McMurtry reduce cell evaluation time by 70% through data driven testing and modelling.
Motorsports
McMurtry Automotive: Faster cell evaluation
McMurtry Automotive used The Voltt and validated cell models to evaluate the transition from the Molicel P45B to P50B during early pack concept development.
Side by side modelling enabled rapid comparison of electrical and thermal behaviour, avoiding lengthy physical test campaigns. This approach reduced cell evaluation time by seven months, allowing the team to lock in cell selection and pack assumptions earlier while lowering technical risk and accelerating vehicle development.
Comparison with Related Cells
Compare the FEB 68E with similar Cylindrical 21700 cells offering comparable capacity and performance characteristics.
Model
Capacity
Max Discharge
Typical Use
Access Cell Data
Manufacturer Background
FEB
FEB is a Chinese cylindrical lithium-ion cell manufacturer
Far East Battery, trading as FEB, was founded in 2009 and is a core subsidiary of the listed Far East Smart Energy group. The company develops and manufactures cylindrical lithium-ion cells, modules and complete pack systems, with the 18650 and 21700 formats forming the backbone of its catalogue. FEB serves electric vehicles, stationary energy storage, electric two-wheelers, power tools and consumer electronics, giving it volume across several high-turnover segments. It has pushed mass-produced 21700 capacity upward in successive steps, releasing higher-capacity variants ahead of much of the market while holding the same cell dimensions. Its position rests on capacity records within established formats rather than novel chemistries.
Frequently Asked Questions
What is the capacity and voltage of the FEB 68E?
The FEB 68E has a nominal capacity of 6.5 Ah and a nominal voltage of 3.6 V, providing 23.4 Wh of energy per cell.
What is the maximum continuous discharge capability of the FEB 68E?
The FEB 68E supports continuous discharge rates up to 13 A, delivering a power density of 624 W/kg.
How much does the FEB 68E weigh and what is its volume?
The cell has a mass of 75 g and a volume of 26.12 cm³.
In which industries is the FEB 68E commonly used?
The FEB 68E is used across aviation, e-mobility, drones, applications that demand high energy density and long runtime.
What is The Voltt and how does it accelerate cell evaluation?
The Voltt holds 500+ verified commercial cell datasheets alongside validated simulation models built from cells characterised in About:Energy's own lab. Engineers screen candidates against their real duty cycle before buying hardware, which cut cell evaluation time by seven months for McMurtry Automotive and reduces evaluation cycles by up to 70%.
What data can be extracted using The Voltt?
Constant-current discharge curves at multiple C-rates, DC internal resistance against state of charge and temperature, pulse power maps, thermal response, and full mission-profile simulation with user-defined pack configurations. Models are available as equivalent circuit, thermal, physics-based and degradation formats, exportable for use in MATLAB, Simulink and Python workflows.
