Short Circuit Formation Research Articles

Prognosis of Internal Short Circuit Formation in Lithium-Ion Batteries: An Integrated Approach Using Extended Kalman Filter and Regression Model

Prognosis of Internal Short Circuit Formation in Lithium-Ion Batteries: An Integrated Approach Using Extended Kalman Filter and Regression Model

Transient Short Circuit-Based Degradation of Lithium and Sodium Anode-Free Batteries

The demand for an extended range of electric vehicles has created a renaissance of interest in replacing the common lithium-ion with a higher energy-density metal anode (e.g., Li or Na). However, alkali metal cells suffer from capacity fading and potential safety issues. The uneven metal electrodeposition often results in dendrite formation and potentially hazardous situations such as cell short-circuiting and thermal runaway.Though lithium plating has been studied widely, a better understanding of the short-circuiting mechanisms and metal battery failure is required. Moreover, a considerable performance gap exists between symmetric metal cells and realistic metal batteries."Soft shorts" are small localised electrical connections between two electrodes that allow the co-existence of direct electron transfer and interfacial reaction. Although soft shorts were identified as a major safety issue in the early nineties, their detection and prevention were not widely studied. Therefore, a fundamental understanding of passivated metals' plating and a reliable testing method for soft short circuits is critical for realising metal batteries, such as Li-Air, Li-S, and anode-free batteries.Here we compared short circuit formation mechanisms and degradation in symmetric cells and anode-free lithium and sodium batteries using coupled galvanostatic impedance spectroscopy (GEIS) and in-situ nuclear magnetic resonance spectroscopy (NMR) for the first time.The coupling of in-situ NMR and EIS allows the observation of metal batteries' electrochemical and chemical dynamics and degradation in real time without affecting the cells' operation.We demonstrated that lithium and sodium short circuit formation mechanisms fundamentally differ and strongly depend on electrolyte composition and SEI stability. This new understanding of the metal plating mechanism is crucial to develop the next generation of rechargeable batteries with high energy density, prolonged cycling life and improved sustainability.

Design Strategies for Anodes and Interfaces Toward Practical Solid-State Li-Metal Batteries.

Solid-state Li-metal batteries (based on solid-state electrolytes) offer excellent safety and exhibit high potential to overcome the energy-density limitations of current Li-ion batteries, making them suitable candidates for the rapidly developing fields of electric vehicles and energy-storage systems. However, establishing close solid-solid contact is challenging, and Li-dendrite formation in solid-state electrolytes at high current densities causes fatal technical problems (due to high interfacial resistance and short-circuit failure). The Li metal/solid electrolyte interfacial properties significantly influence the kinetics of Li-metal batteries and short-circuit formation. This review discusses various strategies for introducing anode interlayers, from the perspective of reducing the interfacial resistance and preventing short-circuit formation. In addition, 3D anode structural-design strategies are discussed to alleviate the stress caused by volume changes during charging and discharging. This review highlights the importance of comprehensive anode/electrolyte interface control and anode design strategies that reduce the interfacial resistance, hinder short-circuit formation, and facilitate stress relief for developing Li-metal batteries with commercial-level performance.

Mediating Lithium Plating/Stripping by Constructing 3D Au@Cu Pentagonal Pyramid Array

Lithium (Li) metal is perceived as the “holy grail” of anodes for secondary batteries due to its innate merits. Regrettably, the commercial application of Li metal anodes (LMAs) has been hampered by problems derived from the uncontrollable growth of Li dendrites, which could result in formation of short-circuits, thereby leading to fatal safety accidents. Here, a three-dimensional lithiophilic gold (Au)-coated copper (Cu) pentagonal pyramid array (Au@CuPPA) is constructed on planar Cu foil via electrodeposition followed by a chemical reduction method. Owing to the features of the lithiophilic layer and 3D porous structure, the proposed Au@CuPPA can not only facilitate Li-ion migration and charge transfer, but also effectively diminish the nucleation overpotential. Consequently, an even and steady Li plating/stripping process for up to 460 h and with a charge capacity of 3 mAh cm−2 is accomplished by using the Au@CuPPA current collector. The Li@Au@CuPPA|LiFePO4 full cell achieves a high Coulombic efficiency (CE) of 99.4% for 150 cycles at 0.5 C with a capacity retention of 92.4%.

Numerical simulation of electrochemical migration of Cu based on the Nernst-Plank equation

Electrochemical Migration (ECM) is getting more attention in the microelectronics industry due to the continuing miniaturization, which increases the possibility of short circuit formation caused by the ECM-induced dendrites. This work presents a 2D numerical model of the ECM based on the Nernst-Plank equation. The model contains the deterministic description of the metal dissolution, the changes of electrolyte properties, and the ion transport in the electrolyte. However, the reduction of the ions and the dendrite growth is described stochastically. The capability of the model was tested in the case of pure copper electrodes with a gap distance 200 µm, 10 VDC bias, 20 °C temperature, and a contaminant-free electrolyte. The results of the model were validated by experimental water-drop tests. The results showed very good agreement between the experimental and the calculated mean time to failure values, dendrite morphologies, and the kinetics of the dendrite formation. The model showed that the developing dendrites consume most of the Cu2+ ions around them, which answers why only some dominant dendrites can develop in a given area. The model proved that not only the electric field but the diffusion of the ions is also dominant in given phases of the ECM process. Our model could be a useful tool for ECM failure prediction and for further ECM researches as the digital twin of the ECM process. Also the approach can be applied in various aspects of failure-prediction in modern reflow-soldering.

Understanding Degradation Effects of Elevated Temperature Operating Conditions in Polymer Electrolyte Water Electrolyzers

The cost of polymer electrolyte water electrolysis (PEWE) is dominated by the price of electricity used to power the water splitting reaction. We present a liquid water fed polymer electrolyte water electrolyzer cell operated at a cell temperature of 100 °C in comparison to a cell operated at state-of-the-art operation temperature of 60 °C over a 300 h constant current period. The hydrogen conversion efficiency increases by up to 5% at elevated temperature and makes green hydrogen cheaper. However, temperature is a stress factor that accelerates degradation causes in the cell. The PEWE cell operated at a cell temperature of 100 °C shows a 5 times increased cell voltage loss rate compared to the PEWE cell at 60 °C. The initial performance gain was found to be consumed after a projected operation time of 3,500 h. Elevated temperature operation is only viable if a voltage loss rate of less than 5.8 μV h−1 can be attained. The major degradation phenomena that impact performance loss at 100 °C are ohmic (49%) and anode kinetic losses (45%). Damage to components was identified by post-test electron-microscopic analysis of the catalyst coated membrane and measurement of cation content in the drag water. The chemical decomposition of the ionomer increases by a factor of 10 at 100 °C vs 60 °C. Failure by short circuit formation was estimated to be a failure mode after a projected lifetime 3,700 h. At elevated temperature and differential pressure operation hydrogen gas cross-over is limiting since a content of 4% hydrogen in oxygen represents the lower explosion limit.

Effects of Polyacrylonitrile Anchoring Polymer Layer Solder Anisotropic Conductive Films on the Solder Ball Movement for Fine-Pitch Flex-on-Flex (FOF) Assembly

In this paper, anchoring polymer layer (APL) solder anisotropic conductive films (ACFs) combined with an ultrasonic (US) bonding method are newly introduced. The effects of APL ACFs properties on conductive particle movement and interconnection stability for ultrafine-pitch chip-on-glass applications were reported earlier. It was found that the APL structure not only suppresses the conductive particles movement during the ACFs bonding process for ultrafine-pitch applications, but also prevents electrical short-circuit formation between neighboring bumps. However, to achieve a stable electrical interconnection, APL ACFs require additional process steps such as an oxygen plasma etch process to remove the APL polymer skins surrounding the conductive particles using a thermocompression bonding method. However, during the US bonding process, it was found that the polyacrylonitrile (PAN) polymer skin coated on conductive particles was successfully removed by vertical directional US vibration. Therefore, stable and metallurgical solder joint formation can be achieved without an additional oxygen plasma etching process.

82‐4: Effects of the Anchoring Polymer Layer (APL) Materials on Conductive Particle Movements for Ultra‐Fine Pitch Chip‐on‐Glass (COG) Interconnection

In this study, APL has been introduced into the ACFs system. Then, the effects of APL ACFs properties on the conductive particle movement and interconnection stability of ultra‐fine pitch COG applications were investigated. The APL structure can not only significantly suppress the conductive particles movement for ultra‐fine pitch COG applications but also prevent electrical short circuit formation between electrodes. After ACFs bonding process, the percentage of captured conductive particles of the conventional ACFs was 33%, however, that of PAN APL ACFs showed 95%. In addition, the APL ACFs showed excellent electrical properties such as stable contact resistance without any open or short circuits.

Ball Grid Array Interconnection Properties of Solderable Polymer–Solder Composites With Low-Melting-Point Alloy Fillers

In this work, a novel ball grid array (BGA) interconnection process has been developed using solderable polymer–solder composites (SPCs) with low-melting-point alloy (LMPA) fillers to enhance the processability of the conventional capillary underfill technique and to overcome the limitations of the no-flow underfill technique. To confirm the feasibility of the proposed technique, a BGA interconnection test was performed using four types of SPCs with a different LMPA concentration (from 0 to 5 vol %). After the BGA interconnection process, the interconnection characteristics, such as morphology of conduction path and electrical properties of the BGA assemblies, were inspected and compared. The results indicated that BGA assemblies using SPC without LMPA fillers showed weak conduction path formation, including open circuit (solder bump loss) or short circuit formation because of the expansion of air voids within the interconnection area due to the relatively high reflow peak temperature. Meanwhile, assemblies using SPC with 3 vol % LMPAs showed stable metallurgical interconnection formation and electrical resistance due to the relatively low-reflow peak temperature and favorable selective wetting behavior of molten LMPAs for the solder bumps and Cu metallizations.

Formation process and photovoltaic properties of Cu(In,Ga)Se2 and (Ag,Cu)(In,Ga)Se2 on flexible stainless steel substrates formed at different selenization temperatures

Cu(In,Ga)Se2 (CIGS) and (Ag,Cu)(In,Ga)Se2 (ACIGS) films were successfully fabricated on stainless steel substrates using the non-vacuum spin-coating process followed by the selenization process. As the selenization temperature was increased to 550 °C, the Voc, Jsc, FF, and conversion efficiency of both CIGS and ACIGS solar cells were enhanced. On selenization at temperature above 550 °C, the morphology of the CIGS films become angular shape, and porous microstructures were formed. EDS and SIMS analyses revealed that the iron ions were substantially diffused from stainless steel substrates into the CIGS absorber layers. The existence of iron ions in CIGS thin films resulted in formation of short circuits of CIGS solar cells, thereby dropping the conversion efficiency of solar cells to zero. On the other hand, the efficiency of ACIGS was higher than that of CIGS solar cells owing to the high band gap and densified thin films. In addition, adding silver ions to the absorber layers effectively enhanced the stability of ACIGS thin films during high-temperature selenization, and suppressed the interaction between the absorber layers and iron ions. This research reveals that the incorporation of silver ions to form ACIGS improved the conversion efficiency at low selenization temperatures, and enhanced the stability of ACIGS films at high selenization temperatures.

Li7La3Zr2O12 Interface Modification for Li Dendrite Prevention

Al-contaminated Ta-substituted Li7La3Zr2O12 (LLZ:Ta), synthesized via solid-state reaction, and Al-free Ta-substituted Li7La3Zr2O12, fabricated by hot-press sintering (HP-LLZ:Ta), have relative densities of 92.7% and 99.0%, respectively. Impedance spectra show the total conductivity of LLZ:Ta to be 0.71 mS cm(-1) at 30 °C and that of HP-LLZ:Ta to be 1.18 mS cm(-1). The lower total conductivity for LLZ:Ta than HP-LLZ:Ta was attributed to the higher grain boundary resistance and lower relative density of LLZ:Ta, as confirmed by their microstructures. Constant direct current measurements of HP-LLZ:Ta with a current density of 0.5 mA cm(-2) suggest that the short circuit formation was neither due to the low relative density of the samples nor the reduction of Li-Al glassy phase at grain boundaries. TEM, EELS, and MAS NMR were used to prove that the short circuit was from Li dendrite formation inside HP-LLZ:Ta, which took place along the grain boundaries. The Li dendrite formation was found to be mostly due to the inhomogeneous contact between LLZ solid electrolyte and Li electrodes. By flatting the surface of the LLZ:Ta pellets and using thin layers of Au buffer to improve the contact between LLZ:Ta and Li electrodes, the interface resistance could be dramatically reduced, which results in short-circuit-free cells when running a current density of 0.5 mA cm(-2) through the pellets. Temperature-dependent stepped current density galvanostatic cyclings were also carried out to determine the critical current densities for the short circuit formation. The short circuit that still occurred at higher current density is due to the inhomogeneous dissolution and deposition of metallic Li at the interfaces of Li electrodes and LLZ solid electrolyte when cycling the cell at large current densities.

Study of Stripping and Deposition of Magnesium in Mg Batteries

Magnesium (Mg) is an attractive material for use in the battery systems for many reasons: it is cheap and abundant; it has high volumetric capacity (3832 mAh/cm3); an attractive negative reductive potential (-2.3 V vs. SHE) and it has less safety issues since Mg is not plagued by dendrite formation.[1]Those properties are a motivation for the development of Mg batteries, but still a lot of additional research must be done on the fields of the electrolytes, suitable cathode materials and understanding the reversibility of Mg stripping and deposition. Despite the results that Mg is not forming dendrites[2], we have noticed non homogenous stripping and deposition of Mg in the different electrolyte solutions. Such non homogenous deposition can overgrow the separator, leading to formation of short circuits. To better understand reasons and to control the parameters that are influencing different morphologies of Mg deposition, we have decided to perform a detailed and systematic study how different electrolyte solutions and impurities (particularly H2O) influence process of Mg stripping and deposition. All the electrochemical measurements were performed in a two electrode beaker cell inside the glove-box (Ar atmosphere). Morphology of Mg foil and nano Mg powder was checked by scanning electron microscope. Solvents with different quantity of water were used for preparation of the electrolyte solutions. We performed two different sets of the electrochemical measurements; cyclic voltammetry and potentiometric cycling. While cyclic voltammetry showed a reversible stripping and deposition process, the potentiometric cycling revealed more information about the efficiency and kinetics of the process. Figure 1a presents Mg stripping and deposition process at a constant current in the first few cycles, showing that the electrodeposition process is taking part at two different potentials. Those two steps can be only observed when the source of Mg is not infinitive (as a positive electrode we typically used copper foil). To better understand the electrochemical processes occurring during the stripping and the deposition, we performed a controlled experiment where Mg was galvanostatically deposited on the Cu (Cu1) positive electrode (charge used for stripping was 0.5 Ah). Then Mg negative electrode was replaced by a fresh Cu electrode (Cu2) and Mg, deposited on Cu1 electrode, was galvanostatically cycled between two Cu electrodes (Cu1 and Cu2), which were examined under SEM at various stages of Mg deposition. Mg deposits appear at two different particle sizes (Figure 1b) and we found that smaller particles are consumed at the beginning of galvanostatic cycling; for the stripping of larger particles a certain overpotenital is required, which is then observed as a second potential. Working with different current densities we additionally found out that the size of particles depends on the current density, used for galvanostatic experiment. Low current densities are leading to large spherical particles, while with high current densities we obtained numerous small spherical particles. We need to point out that non homogenous electrodeposition of Mg can lead to disintegration of the bigger Mg particles from Mg foil surface and consequently to lower Coulombic efficiency as it was observed from our experiments. Careful analyses of Mg foil reveal a pitting corrosion on the surface. The reason for pitting corrosion formation has been studied. Our focus was on the water content in the solvent, which was found to have a large effect on the surface density and size of corroded spots. Besides lower Coulombic efficiency, problems related with the corrosion can importantly influence Mg battery behavior. Although the Mg does not form dendrites, the use of the Mg foil has several restrictions, among them two are exposed in this work. The solution to overcome those can be use of an electrode, prepared from Mg nano powder. Nano Mg powder deposition and stripping follows similar mechanisms as Mg foil, but powder exhibits some improved kinetic properties, which are quite beneficial for overall battery performance and surface deposition seems more uniform than in the case of the foil. Mg foil and nano powder were also tested in the complete Mg battery and we can confirm superiority of Mg nano powder over Mg foil. [1] Aurbach, D.; Cohen, Y.; Moshkovich, M. Electrochem. Solid-State Lett. 2001, 4, A113. [2] Matsui, M. J. Power Sources 2011, 196, 7048. Figure 1

A half millimeter thick coplanar flexible battery with wireless recharging capability.

Most of the existing flexible lithium ion batteries (LIBs) adopt the conventional cofacial cell configuration where anode, separator, and cathode are sequentially stacked and so have difficulty in the integration with emerging thin LIB applications, such as smart cards and medical patches. In order to overcome this shortcoming, herein, we report a coplanar cell structure in which anodes and cathodes are interdigitatedly positioned on the same plane. The coplanar electrode design brings advantages of enhanced bending tolerance and capability of increasing the cell voltage by in series-connection of multiple single-cells in addition to its suitability for the thickness reduction. On the basis of these structural benefits, we develop a coplanar flexible LIB that delivers 7.4 V with an entire cell thickness below 0.5 mm while preserving stable electrochemical performance throughout 5000 (un)bending cycles (bending radius = 5 mm). Also, even the pouch case serves as barriers between anodes and cathodes to prevent Li dendrite growth and short-circuit formation while saving the thickness. Furthermore, for convenient practical use wireless charging via inductive electromagnetic energy transfer and solar cell integration is demonstrated.

Effect of Compression Cycling on Polybenzimidazole‐based High‐Temperature Polymer Electrolyte Membrane Fuel Cells

AbstractContact pressure cycling experiments have been conducted with various commercial high temperature PEM membrane‐electrode‐assemblies based on phosphoric acid doped PBI. Two different membrane‐electrode‐assembly types have been electrochemically investigated employing linear sweep voltammetry, electrochemical impedance spectroscopy and polarization curves, but also micro‐computed tomography imaging has been used as post‐mortem investigation technique. Thickness displacement changes on the membrane‐electrode‐assemblies (MEA) during the experiences have also been recorded. Reversible and irreversible effects have been observed in MEA behavior during the three contact pressure cycles. Furthermore, the micro‐computed tomography tool allows a detailed visual insight into the structural effects of compression forces on the MEA. The electrochemical characterization has revealed that damages under contact pressure cycling have been induced in both kinds of MEAs. Moreover, once MEA damages have appeared, they are facilitated from cycle to cycle. These damages are related to hydrogen crossover and short circuit formation that develop fuel cell performance deterioration. Thus, micro‐computed tomography imaging investigations reveal defects, pin holes or cracks within the catalyst layer and membrane e.g., which may cause degradation aspects like hydrogen crossover or loss of electrical isolation already observed by the electrochemical characterization.

Impact of Contact Pressure Cycling on Non-Woven GDLs of HT-PEM Fuel Cells

The Gas Diffusion Layer (GDL) plays an important role in the performance of a fuel cell, but it also strongly controls the durability of the membrane-electrode-assembly (MEA). Mechanical damages like fiber intrusion at high contact pressure can lead to hydrogen crossover and electrical short circuit formation. In this paper a non-woven GDL is analyzed by electrochemical methods in a fuel cell test station under contact pressure cycling between 0.2 and 1.5 MPa. These results are compared ex-situ with the microscopic structural changes in the material investigated by micro computed tomography in combination with a specially designed compression tool. The optical measurements allow the identification of GDL defects. A clear correlation between the loss of internal resistance and hydrogen crossover current and the emerging of small cracks and fiber intrusions could be established.

In situ Observations and Quantitative Analysis of Short Circuit Probability Due to Ultrahigh Frequency Fatigue

Ultrahigh frequency fatigue (GHz) can lead to the formation of extrusions in aluminum thin film metallizations. Protruding from the surface, such extrusions can connect adjacent electrodes leading to the formation of short circuits. In situ observations presented in this paper verify this belief. Based on measurements from ex situ experiments, we present a defect-based probabilistic model to predict the failure probability, allowing to estimate the lifetime of test devices undergoing such load conditions.

Self-patterned Metal Electrodes by the Fusion Control of Silver Nanoclusters for Inkjet Printing Process

The opportunity of inkjet printing for the fabrication of metal electrodes in electronics applications has been explored for years but the direct fabrication of fine metal electrodes in the scale of tens of micrometers and less has suffered from its limited resolution and reliability. Moreover, the imperfect wetting control of silver ink has caused the short circuit formation between adjacent electrodes, even with a surface energy patterning technique. In this study, a novel self-patterning technique is introduced, which has the capability to convert metallo-organic silver ink to either conductive or non-conductive patterns, as intended. It is found that polyaniline allows the infiltration of metallo-organic silver ink into the voids among polyaniline granules and inhibits the formation of networked silver nanoclusters after a thermal process. With the fusing control layer of polyaniline, conductive and non-conductive patterns were successfully self-differentiated, no matter where metallo-organic silver ink lied down, and the line resistance of the self-patterned metal electrode as fine as 96 μm in line width and 27 μm in line space was as low as 27.55±0.62 Ω/cm.

Copolymerization of polytriphenylamine with coumarin to improve the oxidation potential and LiFePO 4 battery overcharge tolerance

By an oxidative-coupling copolymerization with coumarin, the oxidation potential of polytriphenylamine was improved to 3.75 V from 3.60 V. The copolymer exhibited excellent electrochemical activity in redox cycling. The separator used in the experiment was prepared by roll pressing the copolymer powder with 30% (wt.) polytetrafluoroethylene into a ∼80 μm thick sheet, which was incorporated into a LiFePO 4–Li cell. Tests showed that when the cell was overcharged to 3.789 V, the copolymer separator was oxidized and became electronically conducting, which caused short circuit formation and prevented the organic electrolyte from being oxidized. Although the cell was overcharged at 0.3 C for 5 h, the voltage was stable at 3.789 V. When discharged, the cell released all its capacity at normal charge. The cell was overcharged seven times with identical results obtained for each cycle. Overcharging at different rates demonstrated that the separator could exhibit reversible, self-activating protection for LiFePO 4-based batteries, even at 1.3 mA/cm 2 (3.2 C to the cell).

TECHNOLOGICAL IMPROVEMENT IN COPPER ELECTROMETALLURGY: OPTIBAR SEGMENTED INTERCELL BARS (PATENT PENDING)

This paper summarizes the development of the segmented intercell bars technology for copper electrometallurgy, applicable on both electrorefining (ER) and electrowinning (EW). It starts with how it works and ends with the results of a full scale industrial test. This technological improvement inhibits short circuit formation and improves current efficiency and production levels. These results are accomplished by reducing the current density dispersion. In fact, the cathodes of a plant designed to operate with a nominal 300 A/m2 usually present current densities in a range between 200 and 400 A/m2 (±33% deviations). This high dispersion limits the aim of EW and ER plants for production level increase, quality improvement and cost reduction. Industrial tests performed in a copper ER plant proved that the segmented intercell bar technology halves dispersion and inhibits short circuit formation. Finally, an estimation of economical impact is presented.Cet article résume le développement de la technologie de barres intercellulaires segmentées de l’électrométallurgie du cuivre, qui s’applique tant à l’électroraffinage (ER) qu’à l’extraction par voie électrolytique (EW). On commence par expliquer comment cela fonctionne et l’on termine avec les résultats d’un essai industriel à pleine échelle. Cette amélioration technologique inhibe la formation de court circuit et améliore le rendement du courant et les niveaux de production. On accomplit ces résultats en réduisant la dispersion de densité de courant. En fait, les cathodes d’une usine conçues pour fonctionner avec 300 A/m2 nominal présentent habituellement des densités de courant dans la gamme de 200 à 400 A/m2 (déviations de ±?33%). Cette dispersion élevée limite l’objectif des usines de EW et ER d’augmentation du niveau de production, d’amélioration de la qualité et de réduction des coûts. Les essais industriels effectués dans une usine de ER de cuivre ont prouvé que la technologie de barre intercellulaire segmentée diminuait de moitié la dispersion et empêchait la formation de court circuit. Finalement, on estime l’impact économique.

Copper Electrowinning using Segmented Intercell Bars for Improved Current Distribution

The most widely used technology for obtaining pure copper (>99.999% Cu) from copper oxide ores is LIX-SX-EW (Leaching – Solvent Extraction – Electrowinning). In the EW step, the maximum current that can be applied is partially limited by the possibility of the formation of short circuits. The Walker configuration, despite its apparent robustness and simplicity, exhibits high dispersion of the electrode currents. This paper reviews the current distribution phenomena and proposes a Whitehead based configuration implemented with a multicircuit intercell bar to force the current balance. This arrangement drives the current through more balanced resistance circuits despite intrinsic process parameter deviations. A more even current distribution produces cathodes capable of complying with tighter standards improving chemical and physical cathode quality parameters. Also, the proposed configuration can decrease the probability of short circuit formation allowing operation at higher current densities. Finally, use of the proposed electrical arrangement makes possible the continuous measurement of the flow of current in each electrode using current sensors. This allows for the early detection/correction of short circuits and continuous monitoring of the current distribution in the whole cellhouse.