Electrolyte Channel Research Articles

Insight into the transport of ions from salts of moderated solubility through nanochannels: negative incremental resistance assisted by geometry.

In this study, the transport of salt with moderate solubility through bioinspired solid-state nanochannels was comprehensively investigated. For this purpose, bullet-shaped channels were fabricated and exposed to KClO4, a monovalent salt with moderate solubility. These channels displayed the typical rectifying behavior characteristic of asymmetrical channels but with one remarkable difference, the iontronic output exhibited a negative incremental resistance phenomenon of high gating efficiency when the transmembrane voltage in the open state was increased enough, giving rise to an inactivated state characterized by a low and stable ion current. The behavior is attributed to salt precipitation inside the channel and remarkably, it is not observed in other geometries such as cylindrical or cigar-shaped channels. Considering the central role of the surface in precipitation formation, the influence of several parameters such as electrolyte concentration, pH, and channel size was studied. Under optimized conditions, this system can alternate among three different conductance states (closed, open, and inactivated) and exhibits gating ratios higher than 20. Beyond its potential application in fields related to electronics or sensing, this study provides valuable insight into the fundamental principles behind ion rectifying behavior in solid-state channels and highlights the implications of surface phenomena at the nanoscale.

Evaluation of in-plane architecture in a thermo-electrochemical cell with nanostructured and porous Sb:SnO2 electrodes

Thermo-electrochemical cells (TECs) are able to convert heat into electricity. They are formed by two electrodes (typically Pt) separated by a redox electrolyte (usually 0.4 M aqueous ferro/ferricyanide). The widely adopted architecture of TECs consists of the two electrodes separated by an electrolyte channel. To our knowledge, no studies have been reported exploring a different architecture. Here, we evaluate an alternative configuration, which comprises a substrate with the two electrodes at its ends and with the electrolyte added on the top contacting both electrodes, forming a planar configuration. We explore first the use of the standard Pt electrodes deposited on top of a conductive glass substrate. Then, we replace the Pt by nanostructured and porous Sb-doped SnO2. The planar configurations are compared with their corresponding typical architectures using the common ferro/ferricyanide electrolyte. It was found that the planar TEC with Sb:SnO2 reached a temperature coefficient of 1.76 mV/K, higher than the value obtained in the standard configuration with Sb:SnO2 (1.21 mV/K), and also higher than the planar architecture with Pt electrodes, which showed the typical value for the ferro/ferricyanide electrolyte (1.45 mV/K). As a consequence of this significantly larger value, a 29.7 % higher maximum power output than the planar TEC with Pt was observed. Our study identifies for the first time interesting new features when a planar architecture is employed, opening the door to explore in more detail this alternative configuration in TECs.

A groovy laser processing route to achieving high power and energy lithium-ion batteries

3D-structured NMC622 with precisely controlled electrolyte channels were manufactured by incorporating femtosecond laser processing with conventional slurry casting. Demonstrated in a full cell for the first time, the 3D electrode structures mitigate plating and dendrite growth at the graphite electrode and lead to improved cycling performance, 75 % capacity retention vs 58 % after 500 cycles. 3D-structured NMC622 with a high areal capacity, 5.5 mAh cm−2, exhibits an areal capacity retention of ∼70 % and volumetric capacity exceeding 250 mAh cm−3 at ∼1.15C, three times and twice that of a conventional slurry-casted NMC622, respectively. The improved rate performance is attributed to the enhanced ionic transport and reduced charge transfer resistance facilitated by the 3D electrode structure, as shown through galvanostatic titration measurements. A finite element method-based 3D model illustrated the improved uniform distribution of Li-ion concentration and state of charge within the 3D-structured electrode. Additionally, the 3D electrode structure proved beneficial for wettability and accelerated electrolyte absorption, leading to improved manufacturing efficiency.

Emerging Frontiers in Multichannel Membrane Capacitive Deionization: Recent Advances and Future Prospects.

Capacitive deionization (CDI) has emerged as a promising desalination technology and recently promoted the development of multichannel membrane capacitive deionization (MC-MCDI). In MC-MCDI, the independent control of multiflow channels, including the feed and electrolyte channels, enables the optimization of electrode operation in various modes, such as concentration gradients and reverse voltage discharge, facilitating semicontinuous operation. Moreover, the integration of redox couples into MC-MCDI has led to advancements in redox-mediated desalination. Specifically, the introduction of redox-active species helps enhance the ion removal efficiency and reduce energy consumption during desalination. This systematic approach, combining principles from CDI and electrodialysis, results in more sustainable and efficient desalination. These advancements have contributed to improved desalination performance and practical feasibility, rendering MC-MCDI an increasingly attractive option for addressing water scarcity challenges. Despite the considerable interest in and potential of this process, there is currently no comprehensive review available that covers the operational features and applications of MC-MCDI. Therefore, this Review provides an overview of recent research progress, focusing on the unique cell configuration, vital operation principles, and potential advantages over conventional CDI. Additionally, innovative applications of MC-MCDI are discussed. The Review concludes with insights into future research directions, potential opportunities in industrial desalination technology, and the fundamental and practical challenges for successful implementation.

CFD modeling and simulation of benzyl alcohol oxidation coupled with hydrogen production in a continuous-flow photoelectrochemical reactor

Various conversion routes of biomass and its derivative compounds into high-value products has attracted attention from researchers recently. Among these, a solar-driven photoelectrochemical (PEC) oxidation approach of biomass alcohols to aldehydes is particularly of great interest for the potential applications because the reaction is selective and simultaneously accompanied with hydrogen production. Here, we propose a simulation of selective oxidation of benzyl alcohol into benzaldehyde coupled with hydrogen production in a 2-dimensional continuous-flow PEC reactor using COMSOL Multiphysics (5.6). In order to develop and fabricate a simple yet efficient reactor for a practical use, it is crucial to investigate the effects of operating and design parameters of the reactor on the reactions. Our studies demonstrated that the main contributions to product formation were the electrolyte flow velocity and the width of electrolyte channels. The optimized design parameter exhibited good photoelectrochemical performance with uniform potential distribution within the channels which served diffusion of neutral and charged species and electrochemical reaction. The maximum conversion of benzyl alcohol in this work was 48.25% with 100% selectivity of benzaldehyde. These findings are key for the design of the continuous-flow PEC reactor that can be applied to any series of biomass conversion reactions under mild conditions.

Improving material removal rate and surface roughness in macro electrolyte jet machining of TC4 titanium alloy using tools with a converging-diverging Laval-type electrolyte channel

Improving material removal rate and surface roughness in macro electrolyte jet machining of TC4 titanium alloy using tools with a converging-diverging Laval-type electrolyte channel

Electrolyte imbalance causes suppression of NK and T cell effector function in malignant ascites

BackgroundMalignant ascites commonly occurs in advanced or recurrent stages of epithelial ovarian cancer during peritoneal carcinomatosis and is correlated with poor prognosis. Due to its complex composition of cellular and acellular components malignant ascites creates a unique tumor microenvironment, which mediates immunosuppression and promotes progression of disease. However, the immunosuppressive mechanisms remain poorly understood.MethodsIn the present study, we explored the antitumor activity of healthy donor NK and T cells directed against ovarian cancer cells in presence of malignant ascites derived from patients with advanced or recurrent peritoneal carcinomatosis. A wide range of methods was used to study the effect of ascites on NK and T cells (FACS, ELISA, EliSpot, qPCR, Live-cell and confocal microscopy, Western blot and electrolyte flux assays). The ascites components were assessed using quantitative analysis (nephelometry, potentiometry and clinical chemistry) and separation methods (dialysis, ultracentrifugal filtration and lipid depletion).ResultsAscites rapidly inhibited NK cell degranulation, tumor lysis, cytokine secretion and calcium signaling. Similarly, target independent NK and T cell activation was impaired in ascites environment. We identified imbalanced electrolytes in ascites as crucial factors causing extensive immunosuppression of NK and T cells. Specifically, high sodium, low chloride and low potassium content significantly suppressed NK-mediated cytotoxicity. Electrolyte imbalance led to changes in transcription and protein expression of electrolyte channels and impaired NK and T cell activation. Selected inhibitors of sodium electrolyte channels restored intracellular calcium flux, conjugation, degranulation and transcript expression of signaling molecules. The levels of ascites-mediated immunosuppression and sodium/chloride/potassium imbalance correlated with poor patient outcome and selected molecular alterations were confirmed in immune cells from ovarian cancer patients.ConclusionOur data suggest a novel electrolyte-based mechanism of immunosuppression in malignant ascites of patients with peritoneal carcinomatosis. We show for the first time that the immunosuppression of NK cytotoxicity in coculture assays is correlated to patient poor survival. Therapeutic application of sodium channel inhibitors may provide new means for restoring immune cell activity in ascites or similar electrolyte imbalanced environments.

Abstract P385: Sex-specific Long Non-coding Gene Expression In Rat Nephron Segments

Transcriptomic and proteomic approaches have identified electrolyte transporters, channels and claudins with sex-specific expression along the nephron which adapt to physiological stressors in a sex-specific manner to maintain proper fluid and electrolyte homeostasis. Yet, less is known how long non-coding gene expression in specific nephron segments differs between sexes. We performed polyA-independent RNA-seq on manually isolated proximal tubule (PT) and medullary thick ascending limb (mTAL) from 6-7-week-old male and female Dahl salt sensitive rats. Sex specific gene expression differences [log2(fold change) ≥ 0.5 or ≤ -0.5; p adj ≤ 0.05] are summarized in the table. More sex-specific differences of both protein coding and lncRNA genes were detected in PT compared to mTAL. lncRNAs were less likely to demonstrate sex-specific differences than protein coding genes (p=2.59e-12 for PT and p=5.68e-3 for mTAL). Rare lncRNAs were expressed in one sex or the other (sex-exclusive). An interesting example is ENSRNOG00000069167 and ENSRNOG00000063718 which are transcribed on opposite strands from an overlapping sequence in male or female mTAL, respectively. Multiple sex-exclusive lncRNAs were colocalized with protein coding genes significantly enriched in the same sex, suggesting they may be co-regulated within a specific chromatin domain. For example, ENSRNOG00000068738 was exclusively expressed in male PT and is colocalized in a ~560-kbp region with Pcnx1 and Sipa1l1, both of which were also enriched in male PT. Collectively, these results extend our understanding of sex-specific gene expression differences in these nephron segments to include long non-coding genes.

Assessing the Impact of Thick Electrode Structure on the Fast Charge Performance of Lithium-Ion Batteries

The lithium-ion battery (LIB) is a key technology for inexpensive, renewable, and safe energy storage system, but there are a few challenges that need to be addressed to make LIB more efficient. One critical challenge is increasing both energy density and fast charging capability. Increasing electrode thickness can increase the energy density of lithium-ion batteries. However, increasing electrode thickness increases transport limitations and the risk of lithium plating, which limit safe fast charging capability. This work analyzes prospective improvements to the conventional lithium-ion cell electrode structure that may facilitate high energy density and fast charging capabilities. A 2D lithium-ion battery model is applied to five different cell designs to understand the impact of thick electrode structure on performance at different charge and discharge rates for a single cell. These five different cell designs consist of one conventional cell and four cells with electrodes modified by varied electrolyte channel arrangements. The simulated electrodes were taken as Li(Ni1/3Mn1/3Co1/3)O2 (NMC) for the cathode and graphite for the anode. The simulated electrolyte was 1 M lithium hexafluorophosphate (LiPF6) in 1:1 ethylene carbonate (EC) and diethylene carbonate (DEC). All five cells were simulated under discharge at C/10, C/2 and 1C followed by charge at 1C, 3C, and 5C with no rest time prior to charge. Adding electrolyte channels on the anode side was found to facilitate lithium ion transport and reduce the risk of lithium plating. Modification of both electrodes did not present any benefit compared to the conventional cell. Analysis of cell behavior based on mass transport Fourier number and a dimensionless mass flux parameter was performed to compare different electrodes at different charge and discharge conditions. These dimensionless parameters provide a means for the general assessment of prospective electrode structure modifications.

High-Throughput Activity Screening of Oxygen Reduction and Oxygen Evolution Catalysts

High-throughput techniques are being actively studied to expedite the evaluation of the electrocatalytic activity of newly developed materials. These techniques include the use of optical sensing or electrochemical array cells in stagnant or hydrodynamic aqueous electrolytes [1-2]. A new high-throughput electrochemical cell has been developed utilizing multiple glassy carbon working electrodes with dimensions comparable to those of a conventional ring-disk electrode (RDE) that are inserted into a channel flow cell (Figure 1) comprised of two PEEK blocks separated by a gasket that defines the electrolyte channel depth. This cell enables evaluation of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) activity as a function of the potential of multiple catalyst samples simultaneously that are deposited on the glassy carbon electrodes using standard methods used for RDE electrodes (e.g., using a hand-held micropipette). As shown in Figure 1, a common reference electrode is located in the lower cell block across an electrolyte channel from the working electrodes and a common counter electrode is located in the electrolyte outlet. Electrolyte flow has been simulated to ensure that the electrolyte is evenly distributed throughout the shallow flow channel with uniform laminar electrolyte flow and identical flow rate for all working electrodes. The new cell is coupled with a Bio-logic multichannel Potentiostat (VSP) that allows the use of multiple working electrodes simultaneously with a common counter electrode and common reference electrode. The catalyst activity and stability results obtained with the new cell have been verified by comparison with RDE measurements for the same catalysts. Acknowledgments This work was supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under the auspices of the Electrocatalysis Consortium (ElectroCat). Argonne National Laboratory is managed for the U.S Department of Energy by the University of Chicago Argonne, LLC, also under contract DE-AC-02-06CH11357.

Improved Rate Capability in Composite Solid-State Battery Electrodes Using 3-D Architectures

The limited rate capability observed at faster charging rates is a critical challenge for composite electrodes in solid-state batteries (SSBs). This becomes further amplified with increasing electrode thickness and higher ratios of active material to solid electrode, which result in trade-offs between energy and power density. To overcome these trade-offs, it is necessary to understand the factors responsible for poor rate capability by exploring new approaches to boost power density without compromising energy density. Herein, we fabricated 3-D patterned composite graphite (Gr/Li6PS5Cl) electrodes with low-tortuosity electrolyte channels using a templating approach. Graphite was chosen as a model system to study inhomogeneous lithiation in composite SSB electrode architectures because of the visible color changes that occur as a function of local state-of-charge. At faster cycling rates (1C), the 3-D patterned electrodes enabled considerably higher accessible capacity (38% increase) compared to the unpatterned control electrodes. These enhancements were visualized using operando video microscopy, where 3-D electrode architectures showed improved homogeneity in the local state-of-charge throughout the electrode thickness. The insights presented here will enable new strategies based on 3-D electrode architectures to overcome power/energy trade-offs in SSBs.

A falling film design for electrochemical CO2 reduction

Utilizing CO2 as a resource for CO production in electrochemical reactors requires gas diffusion electrodes (GDE) that maintain a stable and highly reactive gas/liquid/solid interface. When scaling the process towards industrial application, the pressure difference in the electrolyte channel increases, amplifying instabilities at the multi-phase boundary inside the GDE. To tackle this challenge, a falling film design where the electrolyte is solely driven downwards by gravity is presented in this work. The hydrostatic pressure is then counter weighed by the hydrodynamic pressure drop, leading to a constant pressure between gas and liquid side over the height of the electrode. Three 3D-printed electrolyte frame designs were compared in a flow cell regarding the liquid distribution in the channel. An even distribution could be achieved with 2 mm channel thickness at an electrolyte flow rate of 4000 mL min−1. Electrolysis experiments were carried out using a 100 cm2 silver GDE. Compared to a conventional electrolyte frame design, the falling film design yielded stable process conditions with a Faraday Efficiency to CO of up to 90 % at 100 mA cm−2 and a cell voltage of 5.5 V. The presented design presents a pathway for scaling CO2 electrolyzers in height and sustains a stable long-term process.

Determination of the tortuosity and contact resistances in thick graphite anodes via electrochemical impedance spectroscopy

Developing thick electrodes is vital to achieving the requirement of next-generation of lithium-ion batteries (LIBs) with high energy density. However, the thick electrode suffers from severe polarization, which makes the investigation of its internal impedance and dynamics crucial. Herein, the three types of resistances (ionic transmission resistance, ohmic resistance, and contact resistance) dominated by the composition and microstructure of thick graphite anodes are systematically explored by utilizing electrochemical impedance spectroscopy measurements on the symmetrical cell. Firstly, the relationship between tortuosity (τ) calculated from ionic transmission resistance and porosity (ε) of electrodes is studied, which conforms to the deformed Bruggeman equation (τ=fε−α). And the effect of different morphologies of mesocarbon microbeads (MCMB) and flake graphite (FG) on tortuosity is analyzed, then the mechanism of improving the dynamics of thick graphite anodes through constructing vertical electrolyte channels is clarified. Secondly, the ohmic resistance produced by electronic transmission and by ionic transmission are quantitatively characterized separately. Thirdly, the factors affecting the contact resistance of electrodes are also discussed in detail, revealing that the contact area and electronic resistivity govern the contact resistance. This work contributes to preparing the thick electrodes with low resistances.

Two-phase mass transfer in a vapor-fed microfluidic fuel cell

Microfluidic fuel cells (MFCs) fed with methanol vapor are highly competitive in the field of high-efficient energy sources. However, the lack of a two-phase mass transfer theory within the porous electrode restricts the performance and scalability of this potential power option. Herein, a two-dimensional vapor-fed MFC model for two-phase mass transfer based on the mixed wettability of each porous layer is proposed. The effects of two-phase mass transfer on the reactant transport, electrochemical reaction, ion conduction, and cell performance are deeply discussed. This model provides a plausible theoretical explanation for maintaining adequate ion conductivity in catalyst layer and the transport limitations for methanol and oxygen at each electrode. The low fuel concentrations under high current densities lead to concentration polarization, indicating that the inefficient mass transfer at the anode dominates the cell performance. Under a peak power density of 35 mW cm−2, the vapor-fed MFC’s fuel utilization can reach up to 56%. For scaling up vapor-fed MFCs, the horizontal electrolyte channel and uniformly distributed evaporation surface are ideal for optimizing anode utilization and output power. The proposed model covers a gap in the theory of two-phase mass transfer within vapor-fed MFCs and facilitates its practical implementation for improved electrochemical performance.

Inhomogeneities in the Catholyte Channel Limit the Upscaling of CO2 Flow Electrolysers.

The use of gas diffusion electrodes that supply gaseous CO2 directly to the catalyst layer has greatly improved the performance of electrochemical CO2 conversion. However, reports of high current densities and Faradaic efficiencies primarily come from small lab scale electrolysers. Such electrolysers typically have a geometric area of 5 cm2, while an industrial electrolyser would require an area closer to 1 m2. The difference in scales means that many limitations that manifest only for larger electrolysers are not captured in lab scale setups. We develop a 2D computational model of both a lab scale and upscaled CO2 electrolyser to determine performance limitations at larger scales and how they compare to the performance limitations observed at the lab scale. We find that for the same current density larger electrolysers exhibit much greater reaction and local environment inhomogeneity. Increasing catalyst layer pH and widening concentration boundary layers of the KHCO3 buffer in the electrolyte channel lead to higher activation overpotential and increased parasitic loss of reactant CO2 to the electrolyte solution. We show that a variable catalyst loading along the direction of the flow channel may improve the economics of a large scale CO2 electrolyser.

Assessing the Impact of Electrode Structure on the Fast Charge Performance of Lithium-ion Batteries

Increasing electrode thickness can increase the energy density of lithium-ion batteries. However, increasing electrode thickness increases transport limitations and the risk of lithium plating. This work analyzes prospective improvements to the conventional lithium-ion cell that may facilitate high energy density and fast charging capabilities. A 2D lithium-ion battery model is applied to understand the impact of thick electrode at different C-rates in a single cell stack. Five different cell geometries were analyzed for this work: one conventional cell and four test cases in which the conventional electrode geometries were modified by adding electrolyte channels to increase the rate transfer capability of lithium ions at high C-rates and reduce the risk of lithium plating. All five configurations were simulated in discharge at C/10, C/2, and 1 C followed by simulated charging at 1 C, 3 C, and 5 C with no rest period prior to charge. The addition of electrolyte channels in the anode only results in improved performance with respect to reduced plating risk. Dimensionless parameter analysis was performed to compare the battery performance with different electrode modifications at different C-rates. Scaling behavior based on these parameters clarifies the benefits and limitations of the varied electrode modification approaches.

Numerical modeling and performance analysis of an acid-alkaline aluminum-air cell

The imminent threat of climate change has prompted a global effort to decarbonize the transport sector through the adoption of electric vehicles. Aluminum-air cells have been utilized for this purpose due to their massive energy density, which can be boosted even further by employing an acidic catholyte and an alkaline anolyte. A numerical model of this system would be valuable for designing these cells, but none have been proposed thus far. In this work, we investigated the design of a dual-electrolyte aqueous acid-alkaline aluminum-air cell via numerical modeling to determine potential performance improvements under practical operating conditions. The model was implemented in COMSOL Multiphysics® and validated with experimental voltage and power density curves reported in literature. Afterwards, the performance of the cell was evaluated from its voltage and power density curves, concentration profiles, and ion fluxes. A sensitivity analysis of the cell performance was then conducted with respect to various design parameters and operating conditions to infer possible refinements in the cell's design. Lastly, we simulated cells that were redesigned following observations from the sensitivity analysis. The proposed model showed good agreement with experimental data, most notably at moderate applied current densities and near the maximum power point. H+ and OH− ions are consumed by the electrochemical reactions and a parasitic acid-base neutralization reaction, although the latter is discouraged at higher applied current densities. K+ and HSO4− served as the charge carriers and crossed over to their opposite electrolyte channel to retain electroneutrality whenever H+ or OH− were depleted by the reactions. Lowering the inlet flowrate and employing a thicker separator can reduce the extent of acid-base neutralization without sacrificing the maximum power output. Moreover, enlarging the cathode area can raise the maximum power output while also discouraging acid-base neutralization. Incorporating all three design changes resulted in a 4% increase in the maximum power output and 39% decrease in acid-base neutralization. We also simulated an alternative design that uses a cation exchange membrane, so that electrolyte separation does not rely on the flow pattern, and this yielded an 80% decrease in acid-base neutralization with minimal effect on the power output. The model was based on a proof-of-concept acid-alkaline aluminum-air cell, but it can serve as a baseline for improving the performance of similar cells with more practical designs or geometries.

A Moisture‐Induced Electric Generator with High Output Voltage for Self‐Powered Wearable Electronics

AbstractHarnessing energy from ubiquitous moisture is of intense interest because of its considerable potential in self‐powered wearable electronics. However, most existing moisture‐electric generators (MEGs) have poor output voltage, which limits their application possibility. Herein, a novel moisture‐induced electric generator (MIEG) is successfully fabricated with highly‐efficient electric generation by simply bridging a graphene oxide (GO) film and a bilayer graphene oxide/graphite (GOGH) composite film by a polyvinyl alcohol‐phosphoric acid electrolyte gel. The GO film can effectively boost conductive ion diffusion in the electrolyte channel under moisture adsorption while the bilayer GOGH film enhances a potential between two electrodes and output results based on its hydrophilic GO layer and good conductive graphite layer. These availabilities result in an elevated voltage of 1.1 V and a high current of 25.4 μA (254 μA.cm−2), among the high‐level reported outputs. More excitingly, the device also extends without limit by integrating the MIEG cells into a series or parallel topology. As a breakthrough, MIEG is successfully used as a self‐powered wearable device by finger‐surface contact, proximity‐sensitive touchpads, and a human‐breathing transducer. This work not only opens a new futuristic clean power generation in moisture energy harvesting but also facilitates the development of new innovative, flexible electronics.

Scalable design of zinc-bromine battery in 3-dimensional honeycomb lattice for superior low-cost battery

Most of the existing redox flow batteries adopt 1-dimensionally stacked cells in which electrodes, flow frames, gaskets, and membranes are repeatedly stacked in one direction. However, these stacked cells suffer from system complexity, high cost, and insufficient cell performance. Herein, we suggest an attractive cell configuration with a 3-dimensional ceramic framework by adopting an industrially available cordierite honeycomb structure. We successfully demonstrate a zinc bromine battery (ZBB) with this 3-dimensional framework. Because the porous ceramic structure shows multi-functional characteristics as membranes and electrolyte channels as well as the cell housing, it does not require expensive membranes or flow frames, thus significantly reducing the stack manufacturing cost by about 64.5%. Furthermore, it shows superior behavior in terms of cell performance such as rate characteristics (>97% coulombic and >63% energy efficiencies at 60 mA/cm2), practical energy density (52 Wh/L), and cyclability over 500 cycles, compared to previous studies on ZBBs. By connecting more channels in serial or parallel mode, flexible scale-up is feasibly demonstrated without any performance degradation.

Electrolyte Channel Design By Physical Model and Machine Learning

Thick electrode is highly effective to increase the specific energy of a battery cell, but the associated increase in transport distance causes a major barrier for fast charging. We introduce a bio-inspired electrolyte channel design into thick electrodes to improve the cell performance, especially under fast charging conditions. The effects of channel length, width, tapering degree and active material width on the electrochemical performance and mechanical integrity are investigated. Machine learning by deep neural network (DNN) is developed to relate the geometrical parameters of channels to the overall cell performance. Integrating machine learning with the Markov chain Monte Carlo gradient descent optimization, we demonstrate that the complicated multivariable channel geometry optimization problem can be efficiently solved. The results show that within a certain range of geometrical parameters, the specific energy, specific capacity and specific power can be greatly improved. At the same time, the maximum first principal stress which is in the cathode region next to the separator can be significantly reduced, giving better mechanical integrity. Comparing to conventional designed cells without electrolyte channels, we show a 79% increase in specific energy using channel design optimization. This study provides a design strategy and optimization method to achieve significantly improved battery performance