LG INR21700 M50

Key features

• NMC 811
  • Li(Ni_0.84Co_0.10Mn_0.06)O₂
  • +1%wt Si
• 267Wh/kg
• 740Wh/litre
• 1176W/kg
• 3261W/litre

Designed to meet

• Safety:
• Transport:
• Quality:

• Nominal Capacity = 5.0Ah
  • Minimum capacity = 4.85Ah
  • 4.921Ah at C/5 [1]
• Nominal Voltage = 3.63V
• Nominal Energy = 18.20Wh
  • Minimum energy = 17.60Wh
• Maximum voltage = 4.20V +/-0.05V
• Cutoff voltage = 2.50V
• Maximum continuous discharge
  • 1.5C at 5°C to 60°C
  • 0.3C at -20°C to 5°C
  • 0.2C at -30°C to -20°C
• Maximum pulse discharge 10s = 80W at 80% SoC
  • max pulse current =
• Maximum charge
  • 0.7C at 25°C to 50°C
  • 0.3C at 0°C to 25°C
• Operating temperature range = °C
• Storage temperature range °C
• Cycle life

Dimensions

• Dia: ≤21.10mm
• H: ≤70.15mm
• Volume: litres
• Mass: 0.068kg +/-0.001kg

The diameter is given based on largest measurement at the top of the cell (Section A)

Test data

• Maximum discharge current =
• Short circuit current =
• ACIR ≤25mΩ @1 kHz
• DCIR = 30+/-6mΩ 30s 0.5C

Capacity vs Temperature

Reference 1 has many continuous discharge curves for this cell from 0.2A up to 20A continuous.

DCIR vs Temperature

The DCIR was measured by Popp et al [6] at 3 C-rates and at different temperatures. The DCIR values were taken 0.5s into the pulse and have been plotted below versus temperature.

Cycle Ageing

The product data sheet specifies 500 cycles at C/3 charge and C/3 discharge between 4.2V and 2.85V, hence 100% to 0%.

The EU collaborative project iModBatt [Reference 5] has tested and cycled a number of cells.

This data shows that the M50 cycle life decrease rapidly when charged above 1C.

Physical Properties

Chang-Hui Chen et al [7] used this cell to develop the cell teardown, analysis techniques and subsequent mathematical models. The table below comes from this paper and lists some of the physical parameters for the Cathode, Separator and Anode.

Internal Gas Pressure

Gas Pressure Post Formation – Gulsoy et al [1] developed a technique to measure the accumulated pressure within the cylindrical cell post formation, the cell in question was the LG INR21700 M50. The method involved opening the cell and inserting a sensor without incurring a loss of pressure. A bespoke test rig was designed to achieve this. Three cells were tested and the average gas pressure was 260 mbar.

Gas Pressure vs SoC – Gulsoy et al [1] show the gas pressure versus SoC for an LG INR21700 M50 cell and Hemmerling et al [2] show the gas pressure versus SoC for an LG INR18650 MJ1 cell.

Internal gas pressure of instrumented cells with respect to 0% SOC during the processes of (a) charging with C/3 rate and (b) discharging with 1C rate at different ageing stages

Safety data

Independent safety tests of the cell.