Gen Inoue

Kyushu University | Kyudai · Department of Chemical Engineering

Polymer electrolyte membrane fuel cells (PEMFCs) are a key feature of future hydrogen-based societies. The surface-patterning method for electrolyte membranes has been proposed as a performance improvement technique for PEMFCs. However, its underlying mechanism remains unclear because of complicated mass transport and chemical reaction phenomena. I...

Polymer electrolyte fuel cells (PEFCs) are expected to use as a power source for new generation automobiles, especially heavy-duty vehicles because of their low environmental affection. To be widely spread, it is essential to increase their power output and reduce the cost of catalyst platinum. Since oxygen reduction reaction (ORR) at the cathode i...

All-Solid-State Battery (ASSB), which is nonflammable, safe, and high capacity, is expected to be commercialized for electric vehicle applications in the near future. However, the correlation between the electrode structure and the stress on the solid-solid contact surface is unknown, and no design theory has been established. However, the design t...

Even normally shipped batteries may contain disturbing factors such as very small amounts of foreign matter or structural inhomogeneity, which can cause serious accidents such as thermal runaway or explosions. Since dismantling and identifying the cause is time-consuming and costly, nondestructive techniques for identifying the cause are required....

In order to develop high performance Polymer Electrolyte Fuel Cells (PEFCs), the innovative electrode materials are needed and utilized in optimal catalyst structure from the viewpoint of high output density, low amount of Pt and durability. In present PEFC, the resistance of the oxygen reduction reaction (ORR) at the cathode are dominant factors,...

1. Introduction Polymer electrolyte membrane fuel cells (PEMFCs) are highly efficient devices that utilize hydrogen energy. The large overpotential of PEMFCs, particularly under low relative humidity (R.H.) conditions [1], is a challenge. Equivalent circuit modeling is an effective technique for impedance analysis, in which circuit elements are use...

Cathode patterning is an effective means of improving the oxygen reduction reaction in polymer electrolyte membrane fuel cells. Because the conventional one-dimensional transmission line model cannot be applied to micropatterned electrodes, impedance modeling for micropatterned electrodes is conducted using a two-dimensional transmission line matri...

Silicon (Si) alloy provides a high charge capacity as the active material (AM) in anodes of all-solid-state batteries (ASSBs); however, it may expand by up to 300% during charging, which causes capacity losses associated with fragmentation and contact losses. Herein, a simulation framework including fabrication and intercalation of Si anode in an A...

Equivalent circuit modeling is a powerful technique for analyzing the complex impedance of polymer electrolyte membrane fuel cells. The transmission line model, which is based on reactant transport and electrochemical reactions, is frequently applied to porous electrodes. In this study, the distribution of the local charge transfer resistance was c...

In this study, a discrete element method (DEM) that can simulate particle plastic deformation, sintering, and electrode compaction of all-solid-state batteries was developed. The model can simulate elastic, plastic, and viscoelastic deformations that occur particularly in mold compaction processes. When the stress exceeds the yield strength of the...

In the developments of the polymer membrane electrolyte fuel cells (PEMFCs), strategic design of their catalysts layer is a key to improve the performance and durability. Especially, interfacial structure of the electrocatalysts constructed by carbon support, platinum (Pt)-based nanoparticles and polymer electrolyte so called ionomer dominates the...

The negative and positive electrodes of lithium-ion batteries exhibit different structural characteristics. In this study, considering the characteristics of each electrode layer of a lithium-ion battery, the correlation equation of the effective ion conductivity was formulated using a machine learning model. In general, the tortuosity depends on t...

The simulation of a cold-pressed electrode, which consists of active material (AM) particles coated with a solid electrolyte (SE), of an all-solid-state battery (ASSB), is presented. The aim of this study is to elucidate the effect of the SE coating structure on the performance of the ASSB. The new method we developed to simulate the SE-coated AM p...

Understanding ionomer distribution properties that facilitate proton conduction and oxygen transfer to Pt particles in the cathode catalyst layer (CCL) of the polymer electrolyte fuel cell (PEFC) is essential for optimized design of CCL with high cell performance. In this study, the model structure of Ketjen black (KB) as porous carbon was numerica...

The Cover Feature illustrates that high performance lithium‐sulfur battery that can only be achieved under harsh conditions. More information can be found in the Research Article by G. Inoue, M. Watanabe and co‐workers.

All-Solid-state batteries (ASSBs) are non-flammable and safe and have high capacities. Thus, ASSBs are expected to be commercialized soon for use in electric vehicles. However, because the electrode active material (AM) and solid electrolyte (SE) of ASSBs are both solid particles, the contact between the particles strongly affects the battery chara...

Because it is time‐consuming to optimize the design of a cathode catalyst layer (CCL), a numerical simulation to predict the reaction and mass transport characteristics without trial and error is desirable. This study used numerical analysis to investigate how the mass transport occurring in CCLs with flat and three‐dimensional (3D) structures infl...

The volume expansion of anode active materials in all-solid-state lithium-ion batteries strongly affects the dynamic change of electrode structure and its activity of electrochemical reaction and mass transport. Thus, it is important to understand the mechanism and the internal phenomena during the charging process with volume expansion. And also,...

The operation of a lithium‐sulfur (Li−S) battery under lean electrolyte conditions is essential for enhancing the energy density to a practical level. It is rather challenging to reduce the amount of electrolyte in Li−S cells because the discharge reactions of sulfur (Li2Sx formation: x=8−1) occur via a fully dissolution/precipitation conversion me...

The catalyst layer (CL) being the site of electrochemical reactions, is the core subunit of the membrane electrode assembly (MEA) in polymer electrolyte fuel cells (PEFCs). Thus, the porous structure of the CL has a significant influence on oxygen transfer resistance and affects the charge/discharge performance. In this study, the three-dimensional...

Parameter optimization is a long-standing challenge in various production processes. Particularly, powder film forming processes entail multiscale and multiphysical phenomena, each of which is usually controlled by a combination of several parameters. Therefore, it is difficult to optimize the parameters either by numerical-model-based analysis or...

Optimization of the structure of cathode catalyst layers (CCLs) for promoting the transfer of reactants and products in polymer electrolyte fuel cells (PEFCs) is important for improving the cell performance. In this study, using theoretical equations, we confirmed that the shortened proton conduction path in the ionomer layer (IL) with a 3D-pattern...

Reduction of resistances in next-generation secondary batteries, which considerably affects battery performance under high-rate conditions, is essential to increase their output density. In particular, lithium-ion batteries (LiBs) require sufficient contact between the collector and the composite electrode layer. However, contact is often disrupted...

The resistance of the cathode oxygen reduction reaction in polymer electrolyte fuel cells must be reduced for improving the performance. Therefore, it is important to thoroughly understand the relationship between the heterogeneous structures and the cell performance. However, it is difficult to obtain such an understanding using experimental appro...

Early fault detection and correct diagnosis are required for chemical plants. Therefore, the existing fault detection systems using upper/lower thresholds have difficulties to detect faults when the correlation among process variables breaks without excess of any thresholds. In our previous study, an artificial immune system—especially, negative se...

Micropatterns applied to proton exchange membranes can improve the performance of polymer electrolyte fuel cells; however, the mechanism underlying this improvement is yet to be clarified. In this study, a patterned membrane electrode assembly (MEA) was compared with a flat one using electrochemical impedance spectroscopy and distribution of relaxa...

In this study, we investigated the effect of silica (SiO2) layer included in a cathode catalyst layer (CL) on the performance for polymer electrolyte fuel cells (PEFCs). Porous carbons such as Ketjen black (KB) have been widely used as a support for Pt catalysts in PEFCs. Such KB-supported Pt catalyst (Pt/KB) was used as a cathode CL with low ionom...

All-solid-state batteries (ASSBs) have enabled the development of compact and safer batteries with solid and non-flammable electrolytes. However, their practical applications are limited due to the difficulty associated with solid electrolytes (SEs) in forming a connected network for ionic transport and sufficient contact area on the active materia...

The structure of the cathode catalyst layer (CCL) is critically important for improving the performance, durability, and stability of polymer electrolyte fuel cells. In this study, we designed CCLs with a three-dimensional (3D) structure that could increase the surface area of the CCLs to decrease their oxygen transfer resistance. The CCLs were fab...

Optimizing the ionomer/carbon (I/C) ratio in the catalyst layer (CL) of polymer electrolyte membrane fuel cells (PEMFCs) is vital for maximizing PEMFC efficiency. In this study, the effect of the I/C ratio for a platinum (Pt) catalyst loaded on a polybenzimidazole (PBI)-coated Vulcan (Vulcan/PBI/Pt) is compared with a conventional Pt catalyst on Vu...

In order to improve the performance of Lithium-ion secondary batteries (LiBs) for electric vehicles and hybrid electric vehicles, it is very important to understand the internal transport phenomena and resistance under a high rate condition to increase power density. Especially, it is important to focus on the actual porous electrode structure, and...

In order to accelerate the development of polymer electrolyte fuel cells (PEFCs), it is important to optimize the structure of catalyst layers (CLs) including Pt particles, ionomer loading, and porosity, resulting in the improvement of performance. Numerical analysis can assist in designing the optimized CLs without trial and error. In this study,...

We simulated cold press fabrication and intercalation damage in a sulfide All-Solid-State Battery (ASSB) electrode using the Discrete Element Method. We developed a new cohesive hybrid-particulate model that both can simulate particle consolidation during fabrication and material failure during intercalation expansion. In this way, the effect of th...

In order to increase energy density and enhance safety, all-solid-sate lithium-ion batteries have been developed as a storage battery for electric vehicle (EV). Further performance improvement of all-solid-sate lithium-ion batteries requires optimization of the electrode structure. In this paper, we constructed a phase interface model focusing on t...

In recent years, high capacity and high output of secondary batteries such as lithium ion batteries have been desired. The battery uses a porous electrode layer, and its structural design, such as filling factor and geometrical shape, is performed by trial and error. Therefore, design support technology is required to improve development speed. It...

All-solid-state batteries are desired to be used especially for electric vehicles due to the expected features for rapid charging, safety, and unnecessity of battery cooling systems. In recent years, solid electrolytes with high ionic conductivity have been developed. ¹ However, it is known that the effective ionic conductivity in the electrode is...

Polymer electrolyte fuel cell (PEFCs) is a potential power source for new-generation automobiles like fuel cell vehicles that run on hydrogen energy, it has been studied a lot for last decades in order to use as the power sources of automotive. The most important characteristics of PEFCs are low operation temperature and quick start and shutdown. H...

In order to improve the cell performance of polymer electrolyte fuel cells (PEFCs), it is essential to design the cathode catalyst layers (CLs) with the optimal morphology considering the mass transport such as electron, proton, and oxygen as well as an electrochemical reaction. As designing the cathode CLs, it is required to consider the fabricati...

To spread polymer electrolyte fuel cells (PEFCs) widely, which have many advantages, such as low environment load and high energy conversion efficiency, design and optimization of cathode catalyst layers (CLs) are necessary. CLs have inhomogeneous microstructures where Pt catalysts covered with ionomer thin films are supported by carbon particles....

Recently, all-solid-state-lithium-ion batteries have attracted attention as next-generation batteries serving as driving sources for electric vehicles (EVs) and hybrid electric vehicles (HEVs). However, it is required to have more power density and more energy density. In order to develop the performance of batteries, High-capacity negative active...

The development of an all-solid-state lithium-ion battery (ASSB) as a next-generation storage battery is being promoted from the viewpoints of higher energy density and safety, but higher power density is an issue. One of the factors is that the interface resistance is high. At present, research is being actively conducted to reduce interface resis...

Recently, all-solid-state lithium-ion batteries (ASSLiB) has emerged as one of the most promising candidates for next-generation power sources for electric vehicles (EVs) and energy storage. The main reason is the introduction of non-flammable solid electrolyte (SE) which substantially reduces the risk of battery fires. However, more research is ne...

Development of heterogeneous catalysts for energy conversion has been required to solve environmental issues arising from the combustion of fossil fuels. Polymer electrolyte fuel cells (PEFC) are promising power generation devices alternative to the internal combustion engine. PEFC performance is strongly dependent on the catalytic activity for the...

The structure of cathode catalyst layer (CCL) is critically important for improved performance, durability, and stability of polymer electrolyte fuel cells (PEFCs). In this research, two types of CCL are designed to do comparison, one is flat structure, and the other is 3D structure. Inkjet printing method was used in this research to fabricate the...

To spread polymer electrolyte fuel cells, improving the cell performance is required. The cell performance depends on various factors. One of the factors that lowers cell performance is proton transport resistance in catalyst layers. Catalyst layers have multiscale structures which influence on proton transport resistance. In this study, to investi...

Direct formic acid fuel cells (DFAFCs) have received considerable attention because they can generate a higher power density compared to other direct liquid fuel cells. However, when generated CO 2 bubbles are retained in the anode’s porous transport layer (PTL), the performance of the DFAFCs deteriorates. The gas–liquid two-phase flow behavior wit...

we report a proof-of-concept study on CO2 adsorbents synthesized by a thermally initiated free-radical copolymerization and then coated onto carbon paper and poly tetra fluoroethylene via a spray coating approach. A milli-channel reactor was employed to support the obtained materials for efficient CO2 capture with wet conditions, short cooling and...

In this work, we report a proof-of-concept study on CO2 adsorbents synthesized by a thermally initiated free-radical copolymerization and then coated onto carbon paper and poly tetra fluoroethylene via a spray coating approach. A milli-channel reactor was employed to support the obtained materials for efficient CO2 capture with wet conditions, shor...

A particle model for ionomer attachment on carbon black in a Polymer Electrolyte Fuel Cell (PEFC) catalyst layer was developed based the random walk method. Two different methods of particle attachment were used that resemble different catalyst ink preparation conditions: the solution method and the colloidal method. In the solution method, the sim...

Carbon-supported Pt catalysts (Pt/Cs) for use of cathode catalyst layers (CLs) for PEFCs were covered with silica layers in order to improve performance. CLs with low ratio of ionomer to carbon (I/C) for Pt/C and silica-coated Pt/C were fabricated using an inkjet printing (denoted as Pt/C(IJ) and SiO2-Pt/C(IJ)) to reduce oxygen diffusion resistance...

In polymer electrolyte fuel cells (PEFCs), an ionomer is needed to maintain the proton conductivity in the catalyst layer; however, it causes oxygen diffusion resistance because of its thickness on the platinum surface and the blockage of the void spaces. Therefore, understanding the ionomer distribution on a platinum/carbon black (CB) support cata...

We developed a reconstruction simulation model for a catalyst layer of a polymer electrolyte fuel cell to elucidate the effect of the size and shape of the catalyst agglomerates on the cell performance. The geometry of the catalyst layer was obtained by simulating the packing of carbon black agglomerates in ink modeled as multisphere objects by the...

We simulate agglomeration in different fuel cell catalyst ink solutions using Discrete Element Method. Carbon support is modelled as particles in various inks with ionomer and various solvents. The particles interact with particle-pair forces resulting in agglomerate build-up. The classical colloidal theory with van der Waals and electric double la...

Amine-containing nanogel particles as promising absorbents have been developed to reversibly uptake and release CO2 at a low regeneration temperature (75 °C), which is an efficient way to limit the degradation and volatility of amine. It is extremely important to explore a suitable CO2 capture process for further scale-up and industrial application...

Introduction Recently, formic acid is expected as one of the energy career for renewable energy. Especially, direct formic acid fuel cells (DFAFCs) which use formic acid as fuel, have received considerable attention since they can generate higher power density than the other direct liquid fuel cells [1]. However, CO 2 gas is generated in the anode...

Polymer Electrolyte Fuel Cells (PEFCs) are expected to be used for automobiles and various applications because of their high power density and low environmental load. To spread PEFCs, improving cell performance is required. One of the factors that lowers cell performance is proton transport resistance in catalyst layers (CLs) which depends on CLs...

LNG process optimization using Genetic Algorithms was investigated and compared with knowledge-based search algorithm implemented on the same process with the same objective function. The aim was to investigate the effectiveness of such algorithm in contrast to Genetic Algorithms. Scrupulous attention was given to simulating the same process as pre...

Polymer electrolyte fuel cells (PEFCs) are promising for automobiles and various applications because of their high power density and low operating temperature. The cost must be reduced without sacrificing performance of cells by decreasing Pt loading. However, at lower Pt loading, the efficiency decreases because mass transport losses largely incr...

With the development of lithium ion battery (LIB) are recognized as a practical green option for the energy transportation and storage. Over the past decades, solid state batteries (SSB) have received the much attention among the LIB researchers, due to the development of electrolytes with high conductivity comparable to that of the liquid electrol...

Developed novel catalysts has been enhanced its activity and durability by researchers. There are some approaches to enhance Pt activity such as alloy, core-shell, and nanoframe and to improve durability by covered catalysts such as Silica, carbon, and organic compound. However, as for evaluation of catalyst, it is generally difficult to reflect ha...

For the improvement of Lithium-ion Batteries (LiBs) performance, the optimum structure design of porous electrode is needed. In particular, the relationship between porous structure and the internal phenomena has to be understood well from the viewpoint of improvement of capacity, output power density and durability [1]. In LiBs electrode layer, th...

In order to improve the performance of Lithium ion secondary batteries (LiBs) for electric vehicles and hybrid electric vehicles, it is very important to understanding the internal transport phenomena and resistance under high rate condition to increase power density. In our previous studies, we focused on the actual porous electrode structure, and...

The 3D structure of the catalyst layer (CL) in the polymer electrolyte fuel cell (PEFC) is modeled with a Pt/carbon (Pt/C) ratio of 0.4–2.3 and ionomer/carbon (i/C) ratio of 0.5–1.5, and the structural properties are evaluated by numerical simulation. The models are constructed by mimicking the actual shapes of Pt particles and carbon aggregates, a...

The improvement of output density and durability of polymer electrolyte fuel cells (PEFCs) is required for the general spread of fuel cell vehicles. However, there is the subject that Pt catalyst particles make agglomerate under high potential and acid condition. It is directly related to the reduction of durability of cell. To solve this subject,...

Simulation of Optimization and Utilization for LiB with Multi Element Network Lithium ion batteries (LiBs) are used in electric vehicles (EVs), hybrid electric vehicles (HEVs) and so on. However, it is required to have more power density and more energy density. In order to develop the performance of LiB, not only material characteristics such as a...

In order to improve the performance of Lithium ion secondary batteries (LiBs) for electric vehicles and hybrid electric vehicles, it is very important to understanding the internal transport phenomena under high rate condition to increase power density. In our previous studies, we focused on the actual porous electrode structure, and the Li ion and...