Second-life lithium-ion battery aging dataset based on grid storage cycling.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Used lithium-ion battery cells from electric vehicles present potential for second-life applications.
• Grid energy storage systems (ESS) require robust and long-lasting battery solutions.
• Understanding degradation mechanisms in repurposed batteries is crucial for their economic viability.

Purpose of the Study:

• To create an experimental dataset of used lithium-ion battery cells for second-life ESS.
• To analyze the feasibility of second-life applications for aged battery cells.
• To quantify battery degradation under simulated grid storage conditions.

Main Methods:

• Testing of ten INR21700-M50T lithium-ion cells (graphite/silicon anode, NMC cathode) after initial EV use.
• A 24-month aging campaign combining calendar aging at room temperature and cycling under synthetic grid duty cycles.
• Simulated seasonal temperature variations (20°C to 35°C) during cycling.
• Periodic degradation assessments using Reference Performance Tests for second-life (RPT S) and Electrochemical Impedance Spectroscopy (EIS) at various states of charge (SOC).

Main Results:

• The dataset captures the combined effects of cycling-induced stress and long-term calendar aging on battery performance.
• Degradation was monitored through capacity fade and pulse power reduction.
• Electrochemical Impedance Spectroscopy provided insights into changes in internal battery resistance.

Conclusions:

• The experimental data provides valuable insights into the performance and degradation of used lithium-ion cells in grid energy storage.
• This dataset can inform the design and implementation of second-life battery strategies.
• Further research can utilize this data to optimize battery management systems for repurposed batteries.