🔋 Li-ion Battery Simulator

Visualise lithium intercalation, charge/discharge cycles, State-of-Charge (SoC), and how internal resistance and capacity fade evolve over repeated cycling.

C-rate 1.0 C

Temperature 25 °C

Internal resistance 50 mΩ

Capacity degradation 0 %

SoC: 50%

Voltage: 3.70 V

Current: 0.00 A

Power: 0.00 W

Cycle: 0

Avail. capacity: 100%

How it works

Li-ion intercalation: During charge, lithium ions move from cathode (LiCoO₂) through the electrolyte and intercalate into the graphite anode. Discharge reverses this process, releasing electrons via the external circuit.

OCV curve: The open-circuit voltage follows a characteristic S-shaped profile versus SoC. The simulation uses a piecewise Nernst-like function fitted to typical NMC chemistry (3.0–4.2 V range).

Terminal voltage: V_t = OCV ± I·R_int. During charge: V_t = OCV + I·R_int. During discharge: V_t = OCV − I·R_int.

Capacity fade: Repeated cycling causes lithium plating, SEI growth, and electrode cracking, permanently reducing available capacity. Adjust the Capacity degradation slider to simulate an aged cell.

Temperature effect: Low temperatures increase internal resistance and reduce ion mobility. High temperatures accelerate side reactions. The simulation applies a temperature correction factor to R_int.