Non-Destructive Performance Comparison of Li-Ion 2032 Coin Cells for Extreme Temperature Applications

Rechargeable lithium-based coin cells are now commercially available, offering an eco-friendly alternative, but their use is not as widespread. The primary concerns of consumers are safety and reliability in a range of applications. Persistent safety concerns plague lithium-ion battery technology, and batteries of small size are susceptible to rapid heat conduction and physical impacts from dropping and puncturing the battery. Reliability, especially under non-ambient temperature present performance concerns, thus detailed performance tests for coin cells are an urgent matter. We report on a non-destructive, temperature-dependent performance comparison of six different commercially available, rechargeable 2032 coin cell models through galvanostatic cycling: LIR2032 (CT-Energy), LIR2032H (CT-Energy), LIR2032 (EEMB), LIR2032H (EEMB), LIR2032 (LoopaCell) and ML2032 (Maxell). Batteries were cycled over 100 cycles at temperatures ranging from 60°C to 0°C. Performance at room temperature was consistent with the manufacture-provided datasheet for all cells. At high temperatures, all cells except for LIR2032 (EEMB) performed in a stable manner. At cold temperatures, all LIR2032 showed stable performance, yet LIR2032H cells performed poorly. During hot and room temperature cycling we also observed an increase in initial capacity, which may be due to a gradual elimination of concentration polarization between the interface and bulk electrolyte as identified from dQ/dV analysis and EIS. Most cells showed an initial ohmic resistance decrease, then loss of both electrode’s active material at mid-cycles, and faradaic rate decrease of cathode until end-cycles. Both XRD results and dQ/dV analysis allowed prediction of electrode composition:LIR cells were identified as LCO/GIC, and ML2032 (Maxell) being LMO/Mg2Si. Results of scanning electron microscopy and energy dispersive spectroscopy will also be presented to observe interfacial reactions that may be causing the initial capacity increase and cell deterioration.