Xinhua Zhu

Xinhua Zhu
Université Libre de Bruxelles | ULB · Department of Chemistry

PhD

About

22
Publications
4,550
Reads
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195
Citations
Additional affiliations
March 2019 - September 2023
Vrije Universiteit Brussel
Position
  • Postdoc
Description
  • PostDoc researcher for Lithium-based battery technology, focusing on the development of advanced in-situ/operando characterization techniques.
June 2014 - March 2019
Vrije Universiteit Brussel
Position
  • PhD Student
Education
October 2011 - November 2013
Ulm University
Field of study
  • Physical chemistry

Publications

Publications (22)
Article
Full-text available
Kelvin probe force microscope (KPFM) is an AFM-based technique, which can be used for studying lithium ion batteries (LIBs). The capabilities of this technique for practical applications have been explored further in this work. A direct correlation between the local surface potential measured by KPFM and the electrochemical potential of LiNi0.80Co0...
Article
Full-text available
A comprehensive post-mortem study is conducted on the power-optimized LiNi0.80Co0.15Al0.05O2 (NCA) cathode material harvested from large-format commercial pouch cells with different aging conditions. Uneven degradation phenomena are observed in the harvested NCA electrode during the post-mortem analysis. A schematic model, which is associated with...
Article
Full-text available
High voltage cathodes suffer from degradation phenomena that are challenging to observe and identify during cell operation. Dense and smooth sputtered thin films electrodes with an absence of binders and conductive additives allow a direct study of the active material upon Li insertion and extraction at surface and bulk. Using an operando spectrosc...
Article
Electrochemical impedance spectroscopy (EIS) is a powerful technique for characterization of lithium-ion batteries (LIBs). It has extensively been used in laboratory research, but seldom in industrial applications, e.g., electrical vehicles (EVs). This is because the latter needs EIS measurements during operation, but achieving valid EIS measuremen...
Article
Full-text available
Anomalous diffusion impedance due to the solid-state Li⁺ diffusion in Li-ion batteries is often troublesome for the analysis. In this work, we propose a novel analytical Parallel-diffusion Warburg (PDW) model and couple it with the conventional equivalent electrical circuit model (EECM) analysis to tackle this long-standing challenge. The analytica...
Preprint
Full-text available
Anomalous diffusion impedance due to the solid-state Li+ diffusion in Li-ion batteries is often troublesome for the analysis. In this work, we propose a novel analytical Parallel-diffusion Warburg (PDW) model and couple it with the conventional equivalent electrical circuit model (EECM) analysis to tackle this long-standing challenge. The analytica...
Presentation
Electrochemical impedance spectroscopy (EIS) is a powerful non-invasive tool for characterising electrochemical systems. Applied to Li-ion batteries, EIS is shown to be an informative indicator for their state-of-health (SoH) [1,2,3]. However, EIS is limited by the constraints of linearity and stationarity, while Li-ion batteries inherently behave...
Article
Full-text available
Electrochemical impedance spectroscopy (EIS) is a non-invasive technique for examining kinetics of electrochemical systems. Applied to energy storage devices, the impedance contains information about the state-of-charge and state-of-health of a battery. Classical EIS measurements, as implemented in many cyclers, are restricted by two important assu...
Article
Full-text available
Equilibria evolving over time, also called trends, are often present in ongoing measurements of real-life systems. These trends are considered as disturbances when computing the Best Linear Time-varying Approximation (BLTVA) of the system. Current techniques for dealing with trends in BLTVA measurements consist of modelling the trend with a finite...
Article
Full-text available
The solid–electrolyte interphase (SEI), the passivation layer formed on anode particles during the initial cycles, affects the performance of lithium-ion batteries (LIBs) in terms of capacity, power output, and cycle life. SEI features are dependent on the electrolyte content, as this complex layer originates from electrolyte decomposition products...
Article
Full-text available
The class of nonlinear time-varying (NLTV) systems includes all possible systems and, hence, is difficult to identify. Still, when the nonlinearities are not too strong then, depending on the application, a linear model might be sufficient for approximating the true response. To quantify the approximation error of the linear model, detecting and qu...
Presentation
A systematic post-mortem analysis on a batch of power-optimized commercial LiNi 0.80 Co 0.15 Al 0.05 O 2 (NCA) electrodes with different aging conditions was conducted. This aging study provides direct evidence that the intrinsic surface heterogeneity, resulting in locally overcharge reactions, plays a critical role in the degradation of NCA electr...
Article
Full-text available
A comprehensive electrochemical impedance study is conducted on LiNi0.80Co0.15Al0.05O2 electrode material as a function of state-of-charge and aging. Electrodes are harvested from four commercial batteries with different state-of-health conditions. Odd random phase electrochemical impedance spectroscopy and the symmetric cell approach are applied i...
Presentation
Higher power output requires faster charge transfer reactions in the charge/discharge process. Lower activation energy directly correlates to faster Li ion diffusion. Morphology of active materials, binders, separators and electrolytes play an important role in determining the activation energy of a battery system. In [1] the authors showed through...
Presentation
Several electrochemical energy technologies (batteries, fuel cells, supercapacitors, …) have been developed. Many have been commercialized, but a large number is still under development. Systems are optimized in terms of life time, performance and cost, and new systems are being designed. The electrode and electrolyte materials must have the requir...

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