Cylindrical 21700 High-Power Cell
LG Chem H51
Cylindrical 21700 cell delivering 5 Ah capacity with 258 Wh/kg energy density and 25 A maximum discharge rate.
Overview
The LG Chem H51 is a lithium-ion cylindrical 21700 cell designed for applications that demand reliable performance and competitive energy storage. Released in 2024 and with the manufacturer based in South Korea, this cylindrical 21700 cell delivers 5 Ah capacity and 18.2 Wh of energy at a nominal voltage of 3.64 V, with a maximum continuous discharge capability of 25 A, making it well suited to energy-focused applications requiring extended runtime. Its 258 Wh/kg gravimetric energy density is above the 21700 cylindrical median of 257 Wh/kg in the About:Energy battery library.
Key Features
High discharge rate: 25 A continuous (5.0 C)
Energy density: 258 Wh/kg
Power density: 1,291 W/kg
Applications: aviation, motorsports, e-mobility
Technical Specifications from the Manufacturer
Parameter
Manufacturer
LG Chem
Model
INR21700-H51
Type
Li-ion
Form factor
Cylindrical 21700
Country of origin
South Korea
Release year
2024
Nominal voltage
3.64
Energy capacity [Wh]
18.2
Capacity [Ah]
5
Gravimetric energy density [Wh/kg]
258
Gravimetric power density [W/kg]
1291
Max continuous discharge [A]
25
Volume [cm³]
25.09
Mass [g]
70.5
Positive electrode (cathode)
Negative electrode (anode)
Value
Applications & Use‑Cases
The LG Chem H51 is well suited to the following applications due to its cylindrical 21700 form factor and high power 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.
Motorsports: Demands sustained high discharge under competitive load profiles, rapid transient response for acceleration, and thermal stability to maintain performance during race conditions.
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.
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 LG Chem H51 across key indicators, including constant current behaviour, rate capability, temperature dependence, and available power under representative drive cycle conditions.
Constant Current Voltage
Access LG Chem H51 constant-current discharge curves in Voltt to size your pack against the voltage window your system actually needs. (Chart shown is illustrative, not H51 data.)
Constant Current Temperature
Access LG Chem H51 thermal discharge data in Voltt to specify cooling and cell spacing before you commit to a pack layout. (Chart shown is illustrative, not H51 data.)
Pulse Power Behaviour
Access LG Chem H51 pulse power maps in Voltt to set peak current limits and parallel count for your worst-case load. (Chart shown is illustrative, not H51 data.)
Dynamic Profile Response
Access LG Chem H51 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 H51 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 LG Chem H51 with similar Cylindrical 21700 cells offering comparable capacity and performance characteristics.
Model
Capacity
Max Discharge
Typical Use
Access Cell Data
Manufacturer Background
LG Chem
LG Energy Solution is a South Korean manufacturer producing cylindrical, pouch and prismatic lithium-ion cells
LG Energy Solution, formerly the battery division of LG Chem, is headquartered in Seoul and is one of the world's largest lithium-ion cell manufacturers. It produces cylindrical 18650 and 21700 cells alongside pouch and prismatic formats, supplying passenger vehicles, energy storage systems, power tools and consumer electronics. Its cylindrical range uses high-nickel NCM and NCMA cathode chemistry, with capacity and rate variants distinguished by model suffix. Manufacturing spans South Korea, China, Poland and the United States, including joint ventures with automotive partners. Its position rests on supplying most major vehicle manufacturers at scale while holding the quality systems that automotive qualification demands.
Frequently Asked Questions
What is the capacity and voltage of the LG Chem H51?
The LG Chem H51 has a nominal capacity of 5 Ah and a nominal voltage of 3.64 V, providing 18.2 Wh of energy per cell.
What is the maximum continuous discharge capability of the LG Chem H51?
The LG Chem H51 supports continuous discharge rates up to 25 A, delivering a power density of 1,291 W/kg.
How much does the LG Chem H51 weigh and what is its volume?
The cell has a mass of 70.5 g and a volume of 25.1 cm³.
In which industries is the LG Chem H51 commonly used?
The LG Chem H51 is used across aviation, motorsports, e-mobility, applications that demand high power delivery and reliable performance across demanding duty cycles.
How does the LG Chem H51 compare with the Samsung 50U?
Comparing the LG Chem H51 with the Samsung 50U: capacity 5 Ah against 5 Ah; maximum continuous discharge 25 A against 60 A; energy density 258 Wh/kg against 250 Wh/kg; mass 70.5 g against 72 g. Both datasheets can be compared side by side in The Voltt.
What chemistry and format is the LG Chem H51?
The LG Chem H51 is a cylindrical 21700 cell. It has a nominal voltage of 3.64 V and a volume of 25.1 cm³. Its full datasheet is free to view in The Voltt.
