Characterisation of Commercial Li‐Ion Batteries Using Electrochemical Impedance Spectroscopy

Abstract

Electrochemical impedance spectroscopy (EIS) was used to characterize commercial cylindrical Li-ion cells under different state-of-charge (SOC) conditions and up to 300 charge/ discharge cycles to monitor state-of-health (SOH) status. The study included the effect of temperature to access better resolution of the time constants related to the redox reactions at the electrodes. The EIS in the 10 kHz-1 mHz frequency range allowed the elaboration of a comprehensive electrical equiv-alent that incorporated the geometry of the cell and the electrochemical processes occurring at the anode and cathode active material. The fitting procedure of the experimental EIS data to the equivalent circuit produced parameter values that can be used to assess the SOC and SOH of the cell. In the study example, early detection of cell degradation can be obtained using the evolution of Li + diffusion resistance through the solid electrolyte interface (SEI) layer.

Microporous Sulfur–Carbon Materials with Extended Sodium Storage Window

“…The semi‐circle in the mid‐frequency region is associated with the SEI formation and contributes to charge transfer resistance due to the trapped electrons at the interface, [ 37 ] affecting the state‐of‐health (SoH) of the batteries. [ 38 ] The charge transfer resistance (R 1 in Figure S19 , Supporting Information) of SC‐1000 after cycling is the highest among all, which might indicate a lower SoH than the SC‐800 and SC‐900 (Table S4 , Supporting Information). We attribute this phenomenon primarily to the more diffusion‐controlled process observed in SC‐1000, which eventually leads to the growth of a thicker SEI.…”

Coprecipitation Synthesis and Impedance Studies on Electrode Interface Characteristics of 0.5Li2MnO3·0.5Li(Ni0.44Mn0.44Co0.12)O2 Cathode Material

“…To solve the above problems, we must first understand more information about the electrochemical behavior of electrode materials during lithium delithiation/lithiation, including the performance of SEI and the charge transfer process at the electrode/electrolyte interface, which play a key role in cycle stability and capacity maintenance. EIS is one of the most effective instruments for researching the interface properties of electrode materials based on the delithiation/lithiation mechanism and has been confirmed before [20][21][22][23][24]. However, there are few studies on the failure mechanism of the electrode interface of Li-manganese-rich electrode materials in systematic EIS testing.…”

Prospects for managing end‐of‐life lithium‐ion batteries: Present and future

“…[63][64][65][66] By swapping out bad cells and reformulating the best match to bring the voltage, capacity, and internal resistance of the entire battery pack into alignment, the remaining energy can be used more efficiently. ReJoule's technology [67,68] for diagnosing battery packs relies on electrochemical impedance spectroscopy (EIS), which uses alternating current swept at many frequencies to measure the health of materials within the battery. More advanced diagnostic techniques are expected to be developed in the coming years to provide data that can be interrogated when a battery pack is decommissioned to facilitate recombination or recycling.…”