State of Charge Estimation for Sodium-Ion Batteries Based on LSTM Network and Unscented Kalman Filter

With the increasing application of sodium-ion batteries in energy storage systems, accurate state of charge (SOC) estimation plays a vital role in ensuring both available battery capacity and operational safety. Traditional Kalman-filter-based methods often suffer from limited model expressiveness o...

Full description

Saved in:
Bibliographic Details
Main Authors: Xiangang Zuo, Xiaoheng Fu, Xu Han, Meng Sun, Yuqian Fan
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Batteries
Subjects:
Online Access:https://www.mdpi.com/2313-0105/11/7/274
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850078235137671168
author Xiangang Zuo
Xiaoheng Fu
Xu Han
Meng Sun
Yuqian Fan
author_facet Xiangang Zuo
Xiaoheng Fu
Xu Han
Meng Sun
Yuqian Fan
author_sort Xiangang Zuo
collection DOAJ
description With the increasing application of sodium-ion batteries in energy storage systems, accurate state of charge (SOC) estimation plays a vital role in ensuring both available battery capacity and operational safety. Traditional Kalman-filter-based methods often suffer from limited model expressiveness or oversimplified physical assumptions, making it difficult to balance accuracy and robustness under complex operating conditions, which may lead to unreliable estimation results. To address these challenges, this paper proposes a hybrid framework that combines an unscented Kalman filter (UKF) with a long short-term memory (LSTM) neural network for SOC estimation. Under various driving conditions, the UKF—based on a second-order equivalent circuit model with online parameter identification—provides physically interpretable estimates, while LSTM effectively captures complex temporal dependencies. Experimental results under CLTC, NEDC, and WLTC cycles demonstrate that the proposed LSTM-UKF approach reduces the mean absolute error (MAE) by an average of 2% and the root mean square error (RMSE) by an average of 3% compared to standalone methods. The proposed framework exhibits excellent adaptability across different scenarios, offering a precise, stable, and robust solution for SOC estimation in sodium-ion batteries.
format Article
id doaj-art-0f619f198b8a437ea5c83dac0ded153e
institution DOAJ
issn 2313-0105
language English
publishDate 2025-07-01
publisher MDPI AG
record_format Article
series Batteries
spelling doaj-art-0f619f198b8a437ea5c83dac0ded153e2025-08-20T02:45:37ZengMDPI AGBatteries2313-01052025-07-0111727410.3390/batteries11070274State of Charge Estimation for Sodium-Ion Batteries Based on LSTM Network and Unscented Kalman FilterXiangang Zuo0Xiaoheng Fu1Xu Han2Meng Sun3Yuqian Fan4School of Information Engineering, Henan Institute of Science and Technology, Xinxiang 453003, ChinaSchool of Information Engineering, Henan Institute of Science and Technology, Xinxiang 453003, ChinaSchool of Information Engineering, Henan Institute of Science and Technology, Xinxiang 453003, ChinaSchool of Computer Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, ChinaSchool of Computer Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, ChinaWith the increasing application of sodium-ion batteries in energy storage systems, accurate state of charge (SOC) estimation plays a vital role in ensuring both available battery capacity and operational safety. Traditional Kalman-filter-based methods often suffer from limited model expressiveness or oversimplified physical assumptions, making it difficult to balance accuracy and robustness under complex operating conditions, which may lead to unreliable estimation results. To address these challenges, this paper proposes a hybrid framework that combines an unscented Kalman filter (UKF) with a long short-term memory (LSTM) neural network for SOC estimation. Under various driving conditions, the UKF—based on a second-order equivalent circuit model with online parameter identification—provides physically interpretable estimates, while LSTM effectively captures complex temporal dependencies. Experimental results under CLTC, NEDC, and WLTC cycles demonstrate that the proposed LSTM-UKF approach reduces the mean absolute error (MAE) by an average of 2% and the root mean square error (RMSE) by an average of 3% compared to standalone methods. The proposed framework exhibits excellent adaptability across different scenarios, offering a precise, stable, and robust solution for SOC estimation in sodium-ion batteries.https://www.mdpi.com/2313-0105/11/7/274SOC estimationlong short-term memory networkunscented Kalman filterequivalent circuit model
spellingShingle Xiangang Zuo
Xiaoheng Fu
Xu Han
Meng Sun
Yuqian Fan
State of Charge Estimation for Sodium-Ion Batteries Based on LSTM Network and Unscented Kalman Filter
Batteries
SOC estimation
long short-term memory network
unscented Kalman filter
equivalent circuit model
title State of Charge Estimation for Sodium-Ion Batteries Based on LSTM Network and Unscented Kalman Filter
title_full State of Charge Estimation for Sodium-Ion Batteries Based on LSTM Network and Unscented Kalman Filter
title_fullStr State of Charge Estimation for Sodium-Ion Batteries Based on LSTM Network and Unscented Kalman Filter
title_full_unstemmed State of Charge Estimation for Sodium-Ion Batteries Based on LSTM Network and Unscented Kalman Filter
title_short State of Charge Estimation for Sodium-Ion Batteries Based on LSTM Network and Unscented Kalman Filter
title_sort state of charge estimation for sodium ion batteries based on lstm network and unscented kalman filter
topic SOC estimation
long short-term memory network
unscented Kalman filter
equivalent circuit model
url https://www.mdpi.com/2313-0105/11/7/274
work_keys_str_mv AT xiangangzuo stateofchargeestimationforsodiumionbatteriesbasedonlstmnetworkandunscentedkalmanfilter
AT xiaohengfu stateofchargeestimationforsodiumionbatteriesbasedonlstmnetworkandunscentedkalmanfilter
AT xuhan stateofchargeestimationforsodiumionbatteriesbasedonlstmnetworkandunscentedkalmanfilter
AT mengsun stateofchargeestimationforsodiumionbatteriesbasedonlstmnetworkandunscentedkalmanfilter
AT yuqianfan stateofchargeestimationforsodiumionbatteriesbasedonlstmnetworkandunscentedkalmanfilter