This paper proposes a fully unsupervised methodology for the reliable extraction of latent variables representing the characteristics of lithium-ion batteries (LIBs) from electrochemical impedance spectroscopy (EIS) data using information maximizing generative adversarial networks. Meaningful representations can be obtained from EIS data even when measured with direct current and without relaxation, which are difficult to express when using circuit models. The extracted latent variables were investigated as capacity degradation progressed and were used to estimate the discharge capacity of the batteries by employing Gaussian process regression. The proposed method was validated under various conditions of EIS data during charging and discharging. The results indicate that the proposed model provides more robust capacity estimations than the direct capacity estimations obtained from EIS, where the mean absolute error and root mean square error are less than 1.74 mAh and 1.87 mAh, respectively, for all operating conditions for lithium-ion coin cells with a nominal capacity of 45 mAh. We demonstrate that the latent variables extracted from the EIS data measured with direct current and without relaxation reliably represent the degradation characteristics of LIBs.
|Publication status||Published - 2022 Feb 15|
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (Ministry of Science and ICT) ( NRF-2017R1E1A1A03070161 , and NRF-20151009350 ), Korea Institute of Energy Technology Evaluation and Planning (KETEP) grants funded by the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20214910100070 ), and Seoul R&BD Program ( SC210026 ) through the Seoul Business Agency (SBA) funded by The Seoul Metropolitan Government .Computing resources were supported by the National Supercomputing Center ( KSC-2020-INO-0056 ) and the National IT Industry Promotion Agency (NIPA), Korea .
© 2021 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Building and Construction
- Mechanical Engineering
- Management, Monitoring, Policy and Law