Lithium-ion capacitors (LICs) bridge the performance gap between traditional lithium-ion batteries and supercapacitors, delivering superior power density, extended cycle life, and significantly higher energy density than conventional double-layer capacitors. These attributes position LICs as a compelling solution for demanding applications such as electric vehicle acceleration, regenerative braking in urban rail systems, wind power smoothing, smart grid stabilization, and uninterruptible power supplies. Their ability to charge in seconds makes them particularly attractive for high-power scenarios, yet rapid charging introduces a serious risk: lithium plating on the anode. This unwanted deposition of metallic lithium can lead to reduced efficiency, capacity fade, increased internal resistance, and in severe cases, dendrite formation that risks short circuits and thermal runaway. Until recently, no direct or precise method existed to monitor lithium plating specifically in LICs during high-rate charging, limiting the safe exploitation of their full potential.
In a groundbreaking study, researchers developed the first accurate detection approach for lithium plating in LICs by employing 3-electrode pouch-type cells and focusing on differential analysis of the anode potential, moving beyond conventional terminal voltage monitoring. This innovative setup allowed precise tracking of plating onset through multiple complementary techniques: differential charging voltage (DCV) during charging, Coulombic efficiency (CE) assessment, and voltage relaxation profile (VRP) analysis post-charge. These methods revealed that lithium plating initiates at a charging rate of 20 C. Below 50 C, the deposited lithium remains largely reversible, stripping back during discharge without significant harm to performance. Above 50 C, however, irreversible "dead" lithium accumulates, confirmed by scanning electron microscopy showing dendritic agglomerates on the anode after cycling. The study also uncovered two distinct reverse reactions following deposition—lithium stripping and lithium intercalation—with potential differences of approximately 20 mV under relaxation and 45 mV under constant-voltage conditions on soft carbon anodes. In constant-current-constant-voltage protocols, the cutoff current in the voltage hold phase critically influences plating behavior, with lower cutoffs exacerbating intercalation and stripping dynamics.
To demonstrate broader applicability, the CE and VRP methods were successfully extended to high-capacity 1,100 F commercial LIC pouch cells, where irreversible plating was detected starting at 70 C. This validation confirms the techniques' reliability for indirect, non-destructive detection in practical, two-electrode systems, offering a pathway to monitor plating without specialized hardware.
These findings carry substantial benefits for energy storage safety and efficiency. By pinpointing safe charging thresholds and distinguishing reversible from irreversible plating, the approach prevents capacity loss and enhances cycle life, while mitigating risks of thermal events in high-power devices. The methods provide actionable data for real-time battery management systems, enabling dynamic adjustment of charging protocols to maintain performance under demanding conditions.
Looking forward, this research opens avenues for optimized LIC charging strategies that maximize power delivery while preserving longevity, such as adaptive multi-stage protocols or integration with advanced thermal management. Future efforts could refine these detection techniques for in-situ application in full systems, explore plating behavior under varied temperatures or aging, and extend insights to hybrid configurations combining LICs with other storage types. Such advancements would accelerate adoption in electric mobility, renewable integration, and high-reliability power backup.
Ultimately, this work represents a pivotal advancement in LIC technology by delivering the first robust framework for lithium plating detection during ultra-fast charging. It equips engineers with essential tools to harness LICs' hybrid strengths safely and effectively, paving the way for more reliable, high-performance energy solutions that support the transition to sustainable, electrified infrastructures.
Reference
Author: Shasha Zhao a b, Xianzhong Sun a b c d, Yabin An a b c, Zhang Guo a e, Chen Li a b d, Yanan Xu a b d, Yi Li f, Zhao Li g, Xiong Zhang a b c d, Kai Wang a b c d, Yanwei Ma a b c d
Title of original paper: Lithium plating accurate detection of lithium-ion capacitors upon high-rate charging
Article link: https://www.sciencedirect.com/science/article/pii/S2773153725000180
Journal: Green Energy and Intelligent Transportation
DOI: 10.1016/j.geits.2025.100268
Affiliations:
a Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
b University of Chinese Academy of Sciences, Beijing 100049, China
c Key Laboratory of High Density Electromagnetic Power and Systems (Chinese Academy of Sciences), Haidian District, Beijing 100190, China
d Shandong Key Laboratory of Advanced Electromagnetic Conversion Technology, Institute of Electrical Engineering and Advanced Electromagnetic Drive Technology, Qilu Zhongke, Jinan 250013, China
e Hubei Key Laboratory of Advanced Technology for Automotive Components, Wuhan University of Technology, Wuhan 430070, China
f Department of Materials Engineering, KU Leuven, Leuven 3001, Belgium
g Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
