Acoustic emission as a function of polarisation: Diagnosis of polymer electrolyte fuel cell hydration state

Bethapudi, Viswanath Sasank; Maier, Maximilian; Hinds, Gareth; Shearing, Paul R.; Brett, Dan J. L.; Coppens, MO

doi:10.1016/j.elecom.2019.106582

Cited by 13 publications

(40 citation statements)

References 18 publications

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“…Observing the acoustic activity for the 70% RH case, as shown in Fig. 4(c), between OCV and~0.65 V (~700 mA cm −2 ) the increase in CAEE for both fractal PEMFCs is similar, implying similar amounts of liquid water in the flow-fields [32]. Similar liquid water levels are maintained in the flow-field for each system; the superior performance of the 2-way fractal PEMFC at lower current density is attributed to the greater land-electrode surface area, which reduces the Ohmic resistance of the system (Fig.…”

Section: Aefp Measurementsmentioning

confidence: 79%

“…2. The AE hit dataset primarily consisted of amplitude (dB), counts, duration (µs), rise time (µs), and absolute energy (aJ) [28,32]. In this study, the acoustic activity was presented as CAEE [32] and peak amplitude (PA) measured from individual acoustic hits, measured over a specified time interval.…”

Section: Acoustic Emission Testingmentioning

confidence: 99%

“…Up until 2500 s, there is a continuous increase in CAEE for both fractal PEMFCs and the corresponding cell voltage remains almost constant in this region. This can be identified as the stabilisation phase in fractal PEMFC operation, where reactants, humidification and liquid water within the cell are developing into a steady state condition [28,32].…”

Section: Cell Voltage Fluctuationmentioning

confidence: 99%

“…They identified that AE from a PEMFC is sensitive to the hydrodynamics of gas flow in the flow-field channels. Building on this preliminary analysis, Bethapudi et al [32] developed a new method, called acoustic emission as a function of polarisation (AEfP) and explored fuel cell operation over a range of current density, reactant relative humidity (RH) and cell operating temperature. AEfP represents the acoustic activity from a PEMFC, generated through mechanical events associated with liquid water droplets emerging from the gas diffusion layer (GDL) and being transported along flow-fields, where they impinge on channel walls.…”

Section: Introductionmentioning

confidence: 99%

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Hydration state diagnosis in fractal flow-field based polymer electrolyte membrane fuel cells using acoustic emission analysis

Bethapudi

Hack

Trogadas

et al. 2020

Energy Conversion and Management

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Techniques for evaluating water management are critical to diagnose the performance of polymer electrolyte membrane fuel cells (PEMFCs). Acoustic emission as a function of polarisation (AEfP) has been recently introduced as a non-invasive, non-destructive method to analyse the water generation and removal inside a PEMFC during polarisation. AEfP was shown to provide unique insight into water management within a conventional PEMFC and correlating it to cell performance. Here, AEfP is used to characterise the performance of fractal PEM-FCs by evaluating the hydration conditions inside them. This is achieved by probing the water dynamics inside two different fractal flow-field based PEMFCs, namely 1-way and 2-way fractal PEMFCs, and measuring the corresponding acoustic activity generated from them. AEfP is performed on the fractal PEMFCs under relatively humid (70% RH) and fully humidified (100% RH) reactant relative humidity (RH) conditions. Flooding in the 2-way fractal PEMFC, as opposed to the 1-way fractal PEMFC, is demonstrated under different operating conditions by the relatively higher acoustic activity it generates. Corroborating evidence of flooding in the 2-way fractal flow-field under different conditions is provided by its polarisation curves, impedance tests and galvanostatic (current hold) measurements.

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Section: Aefp Measurementsmentioning

confidence: 79%

Section: Acoustic Emission Testingmentioning

confidence: 99%

Section: Cell Voltage Fluctuationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Hydration state diagnosis in fractal flow-field based polymer electrolyte membrane fuel cells using acoustic emission analysis

Bethapudi

Hack

Trogadas

et al. 2020

Energy Conversion and Management

Self Cite

View full text Add to dashboard Cite

show abstract

“…It uses a piezoelectric sensor to detect mechanical perturbations emitted by an object and has been applied to a range of electrochemical energy storage devices. It has been used to monitor particle fracture and morphological changes in battery electrodes during charge and discharge (Ohzuku et al, 1997;Rhodes et al, 2010;Villevieille et al, 2010), has been found to be sensitive to Li-ion intercalation and formation of the solid electrolyte interphase (Kircheva et al, 2011;Kircheva et al, 2012) in Li ion batteries, and has also been applied to PEMFCs (Legros et al, 2009;Legros et al, 2010;Bethapudi et al, 2019). Two-phase systems, such as the water-gas mixture in the flow channels of the PEMWE analyzed in this work, are also readily analyzed using AE.…”

Section: Introductionmentioning

confidence: 99%

Diagnosing Stagnant Gas Bubbles in a Polymer Electrolyte Membrane Water Electrolyser Using Acoustic Emission

et al. 2020

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The use of acoustic emission as a low-cost, non-destructive, and operando diagnostic tool has been demonstrated for a range of electrochemical energy conversion and storage devices, including polymer electrolyte membrane water electrolysers (PEMWEs) and fuel cells. In this work, an abrupt change in acoustic regime is observed during operation of a PEMWE as the current density is increased from 0.5 to 1.0 A cm −2. This regime change is marked by a sudden drop in the number of acoustic hits, while hit duration, amplitude, and energy increase significantly. It is found that the change in acoustic regime coincides with a significant extension of the stagnant bubble region in the flow channels of the PEMWE, observed with high-speed optical imaging. These results demonstrate that acoustic emission can be used effectively as an operando diagnostic tool to monitor bubble formation (two-phase flow conditions) in PEMWEs, facilitating rapid testing or prototyping, and contributing to operational safety.

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A Review of Polymer Electrolyte Fuel Cells Fault Diagnosis: Progress and Perspectives

Zhou,

Jervis

2023

Chemistry Methods

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Polymer electrolyte fuel cells (PEFCs) are regarded as a substitution for the combustion engine with high energy conversion efficiency and zero CO2 emissions. Stable system operation requires control within a relatively narrow range of operating conditions to achieve the optimal output, leading to faults that can easily cause accelerated degradation when operating conditions deviate from the control targets. Performance recovery of the system can be realized through early fault diagnosis; therefore, accurate and effective diagnostic characterisation is vital for long‐term serving. A review of off‐line and on‐line techniques applied to the fault diagnosis of fuel cells is presented in this work. Off‐line approaches include electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), galvanostatic charge (GSC), visualisation‐based and image‐based techniques; the on‐line methods can be divided into model‐based, data‐driven, signal‐based and hybrid methods. Since each methodology has advantages and drawbacks, its effectiveness is analysed, and limitations are highlighted.

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Acoustic emission as a function of polarisation: Diagnosis of polymer electrolyte fuel cell hydration state

Cited by 13 publications

References 18 publications

Hydration state diagnosis in fractal flow-field based polymer electrolyte membrane fuel cells using acoustic emission analysis

Hydration state diagnosis in fractal flow-field based polymer electrolyte membrane fuel cells using acoustic emission analysis

Diagnosing Stagnant Gas Bubbles in a Polymer Electrolyte Membrane Water Electrolyser Using Acoustic Emission

A Review of Polymer Electrolyte Fuel Cells Fault Diagnosis: Progress and Perspectives

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