A hybrid framework for lithium-ion battery SOH estimation under partial charging based on ICA reconstruction

Energy Conversion and Management X, vol. 30, pp. 101903

Abstract

Accurate estimation of the State of Health (SOH) of lithium-ion batteries is essential for ensuring safety, extending service life, and enabling predictive maintenance in energy storage applications. Peak features from Incremental Capacity Analysis (ICA) are widely used as Health Indicator (HI)s for SOH estimation. However, ICA curves derived under low C-rate and full operating cycles limits the applicability in practice. To address these limitations, a hybrid framework taking quasi-equilibrium ICA features from partial charging data is proposed. Quasi-equilibrium ICA curves derived from reconstructed OCV (Open Circuit Voltage) enables reliable peak feature extraction as HIs. A Long Short-Term Memory (LSTM) network with multi-head attention is then adopted to model temporal dependencies, while accommodating inputs with variable length through padding and masking mechanisms. The proposed method is validated on both PyBaMM-based simulation under Multi-stage Constant Current (MCC) charging profiles and a real aging dataset from KIT. The results demonstrate Root Mean Square Error (RMSE) values decreasing from 2.7% to 1.1% as the State of Charge (SOC) span during partial charging increases from 26.9% to 51.4% in simulation. On the experimental dataset, the method achieves RMSE decreasing from 2.6% to 1.5% as the SOC span during partial charging increases from 23.8% to 71.4%, demonstrating its robustness and practical applicability.

Authors 6

1. Qi Zhao Aachen Chair of Thermodynamics of Mobile Energy Conversion Systems (TME)

   RWTH Aachen University

   Affiliation as printed

   Chair of Thermodynamics of Mobile Energy Conversion Systems (TME), RWTH Aachen University, Forckenbeckstraße 4, Aachen, NRW 52074, Germany

2. Wenbin Li corresponding Aachen Chair of Thermodynamics of Mobile Energy Conversion Systems (TME)

   RWTH Aachen University

   Affiliation as printed

   Chair of Thermodynamics of Mobile Energy Conversion Systems (TME), RWTH Aachen University, Forckenbeckstraße 4, Aachen, NRW 52074, Germany

3. Chenye Song Aachen Chair of Mechatronics in Mobile Propulsion

   RWTH Aachen University

   Affiliation as printed

   Chair of Mechatronics in Mobile Propulsion (MMP), RWTH Aachen University, Forckenbeckstraße 4, Aachen, NRW 52074, Germany

4. Seyedmehdi Hosseininasab Aachen FEV Europe GmbH

   FEV (Germany)

   Affiliation as printed

   FEV Europe GmbH, Neuenhofstraße 181, Aachen, NRW 52078, Germany

5. Jakob Andert Aachen Chair of Mechatronics in Mobile Propulsion

   RWTH Aachen University

   Affiliation as printed

   Chair of Mechatronics in Mobile Propulsion (MMP), RWTH Aachen University, Forckenbeckstraße 4, Aachen, NRW 52074, Germany

6. Stefan Pischinger Aachen Chair of Thermodynamics of Mobile Energy Conversion Systems (TME)

   RWTH Aachen University

   Affiliation as printed

   Chair of Thermodynamics of Mobile Energy Conversion Systems (TME), RWTH Aachen University, Forckenbeckstraße 4, Aachen, NRW 52074, Germany