Manufacturing Steps Research Articles

Research on Chip Manufacturing and Fault Detection Technology

In the wave of the digital era, the chip plays a key role in promoting the whole information technology revolution with its core position in the development of world science and technology. As the cornerstone of computing and data processing, the development of chips has promoted the progress of the entire technology field. The chip’s manufacturing is the key to determining the performance and computing power of the whole chip, and fault detection technology in the production process is an important part of determining the product’s quality and cost. Therefore, under the background of Moore’s law approaching the physical limit, how to ensure the yield of chip production while continuing to improve chip performance has become a major challenge for the chip manufacturing industry. Based on this, this paper summarizes the key manufacturing steps of the chip. The chip manufacturing technology is comprehensively sorted from design to silicon wafer manufacturing, photolithography, etching, ion implantation, and other processes. At the same time, the research direction of monocrystalline silicon manufacturing technology and the existing lithography technology are introduced, including optical lithography, extreme ultraviolet lithography, electron beam lithography, and so on. Fault detection technology in chip production has also been introduced. In addition, the chip manufacturing and fault detection technology introduced in this paper is summarized and its future development is prospected, which provides reference and inspiration for promoting the continuous progress of chip technology.

Biomaterials for Cell Manufacturing.

Cell therapies, potent populations of cells used to treat disease and injury, can be strategically manufactured with biomaterial intervention to improve clinical translation. In this viewpoint, we discuss biomaterial design and integration into cell manufacturing steps to achieve three main goals: scale-up, phenotype control, and selection of potent cells. Material properties can be engineered to influence the cell-biomaterial interface and, therefore, impart desirable cell behavior such as growth, secretory activity, and differentiation. Future directions for the field should capitalize on the combinatorial design of biomaterial properties to yield highly specific and potent cell populations. Furthermore, future biomaterials could contribute to novel high-throughput cell separation technologies that can individually select the most therapeutically relevant cells within a produced batch.

Powder Compaction Characteristics and Modeling of Calendering Process for Powder-based Solvent-free Manufacturing of Electrodes for Lithium-ion Batteries

Abstract Powder-based solvent-free manufacturing of electrodes for Li-ion batteries represents an emerging and promising technology in electrode fabrication. This method involves a two-roll powder calendering process, where electrode powder materials are compressed onto a current collector to form electrodes with desired properties. The calendering or compaction of dry powders onto a current collector is a crucial step in solvent-free electrode manufacturing, significantly impacting the microstructures, mechanical properties, and electrochemical performance of the produced electrodes. In this paper, we investigate the compaction characteristics of electrode powders to gain insights into their behavior. A powder-on-current collector calendering model is developed based on Johanson's rolling theory of granular solids. This model enables us to infer the underlying calendering parameters essential for the solvent-free manufacturing of Li-ion batteries. To validate the model, we compare it with experimental calendering results, utilizing measured powder properties and roll design parameters as inputs. This approach offers a comprehensive understanding of the effects of roll geometries, particularly roll diameter, and various equipment design parameters on final electrode properties. Such insights have not been thoroughly explored in the emerging field of solvent-free battery electrode manufacturing, thereby contributing to advancements in this area.

4D printing of magnetoresponsive soft gripper and phenomenological approach for required magnetical actuation field

4D printing is the next step in additive manufacturing. Magnetoresponsive materials facilitate the creation of gripping tools through 4D printing, allowing for structural changes in response to external stimuli. In this study, the structural change is manifested as motion, triggered by an external magnetic field. This technology offers significant advantages in medical and industrial applications, including the printing of life-like moving organ models for medical training and the development of actuators for use in explosive environments. Magnetoresponsive materials are programmed with a magnetic profile and actuated by an external magnetic field. A compound of strontium ferrite microparticles SrFe12O19\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SrFe_{12}O_{19}$$\\end{document}(≤20μm\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\le 20\\mu m$$\\end{document}) and an elastic polymer (thermoplastic copolyester) with a Hardness of Shore D 40 was produced. A star-shaped body was programmed and actuated by two permanent magnets, each of Br=1.29-1.32T\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$B_r=1.29 - 1.32T$$\\end{document}. As there is no analytical approach for calculating the required actuation flux density, one has been developed. The approach is verified experimentally by using a Hall probe. It is appropriate to set the field with a Helmholtz coil, despite the utilization of two permanent magnets. The use of a commercial fused filament fabrication printer for the processing of magnetoresponsive materials has been realized here for the first time. The main contributions are the short time constant (around ta=0.1s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$t_a=0.1s$$\\end{document}) for actuation and the repeatability (around n=200\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n=200$$\\end{document} actuation cycles) of the motion. The feasibility of multiple diverse reprogramming is a step forward in 4D printing. Hence, the post-print programming and the inhomogeneity of the field limit the ease of the presented method.

Single-Step Extrusion Process for Formulation Development of Self-Emulsifying Granules for Oral Delivery of a BCS Class IV Drug.

This study aimed to develop and optimize formulations containinga BCS Class IV drug by improving its solubility and permeability. Herein development of self-emulsifying solid lipid matrices was investigated as carrier systems for a BCS Class IV model drug. Self-emulsifying drug delivery systems (SEDDS) have been extensively investigated for formulating drugs with poor water solubility. However, manufacturing SEDDS is challenging. These systems usually have low drug-loading capacities, and the incorporated drugs tend to recrystallize during storage, which severely impacts the storage stability in vitro and performance in vivo. Moreover, they require greater amounts (>80%) of lipid carriers, cosolvents, surfactants, and other excipients to keep them from recrystallizing. This in turn is again challenging for high-dose drugs as it affects the size of the final drug product (tablets and capsules). Also, the final liquid nature of the formulation affects the handling and processability of the formulation, which poses challenges during the manufacturing and packaging steps. In this work, we have studied the feasibility of a single-step extrusion process to formulate and optimize solid self-emulsifying granules with a relatively higher drug loading of Ritonavir (RTV), a BCS Class IV drug. Further, we have compared the performance of using these granules as the feedstock for direct powder extrusion-based 3D printing as opposed to the use of physical blends. The stability and solubility-permeability advantage of these granules was also evaluated where SEDDS showed about 27 and 20 fold increase in apparent solublity and permeability compared to bulk drug, respectively. Combining the capabilities of HME to form drug-loaded homogeneous granules as a continuous process along with application of direct printing extruiosn (DPE) 3D printing improves the drug delivery prospects for such candidates.

Analysis, design & installation of vibration isolation for lightweight helipads: a case study

The heliport isolation aims to mitigate the transmission of helicopter-induced vibrations to the building structure during approach, landing, and take-off by introducing vibration isolators at the supports of the heliport structure. As a case study, this paper presents the design and manufacturing steps for the installation of a vibration isolation solution for two lightweight helidecks installed on the rooftop of an existing medical center building. Design of a very high-performance isolation system for a lightweight helideck, requires a series of stability checks under various load conditions. In practice, the primary challenge is to control the substantial differential deflection of the helideck, which is supported by relatively soft isolators, during approach and landing conditions. The solution delivered was a prefabricated spring box comprising essential components such as failsafe and uplift restraints to deal with the challenging aspects of the isolation of lightweight helidecks. Certainly, a collaborative effort between the isolation solution provider and the helideck supplier facilitated a progressive design process aimed at meeting stringent acoustic performance requirements and addressing the complex functionality of a lightweight helideck. The paper also discusses the challenges and best practices encountered during the production and installation of the system.

A Comparison of Standard SEI Growth Models in the Context of Battery Formation

Growth of the Solid Electrolyte Interphase (SEI) layer on negative electrode particles during the formation cycle is one of the most complex and least understood steps of lithium-ion battery manufacturing. This initial SEI formation significantly impacts battery performance, lifetime, and degradation. Zero-dimensional models, which reduce the complexity of SEI’s morphology, material, and structure, are commonly used to study long-term SEI growth rates and capacity fade. These models are derived based on limiting mechanisms. We aim to compare the most common SEI growth models, focusing on the first few cycles at low C-rates representing formation protocols. Using consistent parameters across models, we seek to understand if they can capture the dynamics of SEI formation. We conducted qualitative comparisons with experimental measurements of Coulombic efficiency in 2032-type coin cells at low C-rate. Our analysis shows that the models predict SEI growth in the first cycle to be higher than in subsequent cycles. However, the difference between cycles in these models is insufficient to explain the experimental results, which indicate a capacity fade during the first cycle that is two orders of magnitude higher than in later cycles. This suggests new models are needed to accurately describe the physics of the formation cycle.

Demonstrating scalability between two blender types using DEM

Powder blending is a critical step in pharmaceutical manufacturing that can impact product quality such as tablet tensile strength. This study utilized the Discrete Element Method (DEM) to investigate blending in a 5-liter mini-batch and a 2-liter Turbula blender. DEM parameters were calibrated using small-scale powder characterization tests, so that the particle behavior in the DEM simulations matches the measured behavior. The research explored the effects of blender designs and process conditions on blending and lubricant dispersion. A predictive model for tablet tensile strength was developed. The model takes the lubricant’s dispersion via the lubrication energy into account. The model is then used to predict the tablet tensile strength depending on the chosen process parameters, blending speed, duration, and fill level. DEM simulations enabled scaling between the two blenders, providing valuable insights for a semi-continuous manufacturing process based on mini-batch blending. The findings contribute to a deeper understanding of blending mechanics, offering potential enhancements in pharmaceutical manufacturing efficiency and product consistency.

Understanding in-vivo refolding of antibody fragments (Fab): Biosimilar Ranibizumab a case study

In-vitro protein refolding is a major bottleneck step in the large-scale manufacturing of antibody fragments expressed in a microbial host system. The formation of an inter-chain disulfide bond is a key rate-limiting step during in-vitro refolding of antibody fragment therapeutics. In this investigation, we report the use of two redox mutant strains of E. coli viz., SHuffle® T7 (DE3) and SHuffle® T7 Express (DE3) possessing an oxidizing cytoplasm for the soluble expression of a refolded biosimilar antibody fragment. The effect of various critical process parameters on antibody fragment refolding yield was studied using a Design of Experiment (DoE) approach. The optimized upstream processing led to the expression of 167 ± 2.53 mg/L and 95 ± 1.44 mg/L of soluble refolded biosimilar Ranibizumab using the SHuffle® T7 (DE3) and SHuffle® T7 Express (DE3) strains, respectively, at the bioreactor scale. Physicochemical characteristics of the in-vivo refolded antibody fragment were studied and compared with an innovator molecule using various orthogonal analytical methods. A biological activity study of in-vivo refolded Ranibizumab using HUVEC cell-based bioassay proved that cell proliferation inhibition is comparable to the innovator Ranibizumab. The proposed strategy offers a time and cost-effective manufacturing platform for antibody fragments.

Characterization of Amnion-Derived Membrane for Clinical Wound Applications.

Human amniotic membrane (hAM), the innermost placental layer, has unique properties that allow for a multitude of clinical applications. It is a common misconception that birth-derived tissue products, such as dual-layered dehydrated amnion-amnion graft (dHAAM), are similar regardless of the manufacturing steps. A commercial dHAAM product, Axolotl Biologix DualGraft™, was assessed for biological and mechanical characteristics. Testing of dHAAM included antimicrobial, cellular biocompatibility, proteomics analysis, suture strength, and tensile, shear, and compressive modulus testing. Results demonstrated that the membrane can be a scaffold for fibroblast growth (cellular biocompatibility), containing an average total of 7678 unique proteins, 82,296 peptides, and 96,808 peptide ion variants that may be antimicrobial. Suture strength results showed an average pull force of 0.2 N per dHAAM sample (equating to a pull strength of 8.5 MPa). Tensile modulus data revealed variation, with wet samples showing 5× lower stiffness than dry samples. The compressive modulus and shear modulus displayed differences between donors (lots). This study emphasizes the need for standardized processing protocols to ensure consistency across dHAAM products and future research to explore comparative analysis with other amniotic membrane products. These findings provide baseline data supporting the potential of amniotic membranes in clinical applications.

The effect of temperature during plasma nitriding on the properties of IN718 additively manufactured by laser beam powder bed fusion

The IN718 superalloy has become a strategic alloy for applications in critical components in aerospace, oil, and gas, or power generation. Commercially, IN718 is produced by conventional casting processes. However, manufacturing is evolving towards 3D printing, which allows the manufacturing of near-net-shape parts and complex designs, thus optimizing manufacturing steps, reducing production costs, and adding other advantages to the final product. However, high corrosion resistance and mechanical strength are required in applications such as oil and gas, whereas IN718 superalloys have limitations. Surface hardening by applying plasma nitriding can protect against corrosion by increasing mechanical strength and wear resistance. For this, plasma nitriding has been widely applied for surface hardening of IN718; however, little is found on the effects of surface treatments (coating or nitriding) of additively manufactured alloys. The effects of temperature during plasma nitriding on the surface properties of IN718 superalloy 3D printed by the Laser Beam Powder Bed Fusion (LB-PBF) method are reported here. Samples of IN718 fabricated by 3D printing were plasma nitrided at fixed temperatures between 500 and 650 °C in a semi-industrial reactor, their effects are analyzed and correlated with their microstructural characteristics, the mechanical properties at the micro- and nanoscale, and the tribological responses in a pin-on-disk configuration.

Manufacturing Process Affects Coagulation Kinetics of Ortho-R, an Injectable Chitosan-Platelet-Rich Plasma Biomaterial for Tissue Repair.

Ortho-R (ChitogenX Inc., Kirkland, QC, Canada) is an injectable combination drug-biologic product that is used as an adjunct to augment the standard of care for the surgical repair of soft tissues. The drug product comprises lyophilized chitosan, trehalose and calcium chloride, and it is dissolved in platelet-rich plasma (PRP), a blood-derived biologic, prior to injection at the surgical site where it will coagulate. The first step of the Ortho-R manufacturing process involves dissolving the chitosan in hydrochloric acid. The purpose of this study was to investigate the effect of increasing the amount of acid used to dissolve the chitosan on final drug product performance, more specifically, on the chitosan-PRP coagulation kinetics. Chitosans were solubilized in hydrochloric acid, with concentrations adjusted to obtain between 60% and 95% protonation of the chitosan amino groups. Freeze-dried Ortho-R was solubilized with PRP, and coagulation was assessed using thromboelastography (TEG). The clotted mixtures were observed with histology. Clot reaction time (TEG R) increased and clot maximal amplitude (TEG MA) decreased with protonation levels as pH decreased. Chitosan distribution was homogeneous in chitosan-PRP clots at the lowest protonation levels, but it accumulated toward the surface of the clots at the highest protonation levels as pH decreased. These changes in coagulation kinetics, clot strength and chitosan distribution induced by high protonation of the chitosan amino groups were partially reversed by adding sodium hydroxide to the dissolved chitosan component in order to decrease pH. Careful control of manufacturing processes is critical, and it is important to consider the impact of each manufacturing step on product performance.

Curved HSIW: an affordable performance for non-planar millimeter-wave applications

This paper introduces a Curved Hollow Substrate Integrated Waveguide (CHSIW) to address the growing demand for millimeter-wave applications, including communication, sensing, imaging, radar, and wireless power transfer systems. Leveraging advancements in integrated circuits and system-in-package (SiP) technology, the CHSIW tackles the challenges associated with hardware integration into curved structures. The design utilizes MultiJet Printing (MJP) for the M3 crystal dielectric substrate and a water laser cutter system for copper sheets, streamlining the fabrication process by eliminating complex via manufacturing steps through prefabricated through-hole vias. Operating in the frequency range of 21.7 GHz to 32 GHz, the CHSIW exhibits outstanding performance on curved surfaces, with measured average attenuation constants of 1.89 Np m−1 (16.42 dB m−1) and 1.95 Np m−1 (16.94 dB/m) for samples with radii of curvature of 166.8 mm and 125.1 mm, respectively. Beyond addressing technical challenges, the CHSIW presents a cost-effective and simplified fabrication process, positioning it as a breakthrough solution for diverse millimeter-wave applications, including future robotic and UAV communications. Furthermore, the proposed design and fabrication technique hold promise for the realization of conformal and free-form Hollow Substrate Integrated Waveguide (HSIW) devices in the future.

How photovoltaic industry policies foster the development of silicon solar cell manufacturing technology: Based on Self-attention mechanism

With the advancement of silicon solar cell manufacturing technology (SSCM-Tec) driven by subsidy policies, some developing countries have implemented subsidy reduction policies. Concurrently, intense international competition has prompted the implementation of restriction policies. However, due to SSCM involving multiple manufacturing steps, each step comprising various SSCM-Tec, it presents challenges in researching how different types of policies affect SSCM-Tec in each step. We construct the SSCM-Mechanism based on patent claims to capture the nuanced changes in SSCM-Tec caused by the implementation of policies. The results show that: (1) Policies lead to an imbalance in SSCM-Tec advancements among manufacturing steps; (2) Different types of policies have varying impacts on SSCM-Tec. Supportive policies boost enterprises' interest in developing SSCM-Tec, and restrictive policies and subsidy reduction policies speed up SSCM-Tec innovation; (3) The collaboration of various policy types can better drive the advancement of SSCM-Tec. Employing the right type of policy at the opportune moment serves as a crucial driving force for fostering innovation in SSCM-Tec. These findings reveal the multifaceted impact of policies on SSCM-Tec, providing policymakers with a clearer perspective to formulate more precise policies for guiding the direction of SSCM-Tec development and accelerating its innovation pace.

Advances in Wafer Probing with Ultra-Short Pitch SoCs

The semiconductor industry is in a constant state of evolution, driven by the relentless pursuit of improved performance, enhanced efficiency, and the ever-decreasing size of electronic devices. A critical aspect of this advancement is the development of ultra-short pitch system-on-chips (SoCs). These SoCs, characterized by their densely packed connections and minimal spacing between contact points, present unique challenges during wafer probing—a crucial step in semiconductor manufacturing. This article delves into the complexities of wafer testing for short pitch SoCs, explores the latest innovations in this domain, and discusses how these advancements are revolutionizing semiconductor manufacturing processes.

High-Viscosity Phase Inversion Separators for Freestanding and Direct-on-Electrode Manufacturing in Lithium-Ion Batteries.

Separators play a critical role in lithium-ion batteries (LIBs) by facilitating lithium-ion (Li-ion) transport while enabling safe battery operation. However, commercial separators made from polypropylene (PP) or polyethylene (PE) impose a discrete processing step in current LIB manufacturing as they cannot be manufactured with the same slot-die coating process used to fabricate the electrodes. Moreover, commercial separators cannot accommodate newer manufacturing processes used to produce leading-edge microbatteries and flexible batteries with customized form factors. As a path toward rethinking LIB fabrication, we have developed a high-viscosity polymer composite separator slurry that enables the fabrication of both freestanding and direct-on-electrode films. A streamlined phase inversion process is used to impart porosity in cast separator films upon drying. To understand the impacts of material composition and rheology on phase inversion processing and separator performance, we investigated four different separator formulations. We used either diethylene glycol (DEG) or triethyl phosphate (TEP) as a nonsolvent, and either silica (SiO2) or alumina (Al2O3) as an inorganic additive in a polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) matrix. Through a down-selection process, we developed a TEP-SiO2 separator formulation that matched or outperformed a commercial Celgard 2325 (PP/PE/PP) separator and a Beyond Battery ceramic-coated PE (CC/PE/CC) separator under rate and cycle life tests in LiFePO4|Li4Ti5O12 (LFP|LTO) and LiNi0.5Mn0.3Co0.2O2|graphite (NMC-532|graphite) coin cells at C/10-1C rates. Our TEP-SiO2 slurry had a viscosity of 298 Pa s at a 1 s-1 shear rate and shear-thinning behavior. When deposited directly onto an LTO anode and cycled against an LFP cathode, the direct-on-electrode TEP-SiO2 separator increased the specific capacity by 58% and 304% at 2C rates relative to the PP/PE/PP and CC/PE/CC separators, respectively. Additionally, the freestanding TEP-SiO2 separator maintained dimensional stability when heated to 200 °C for 1 h and demonstrated a higher elastic modulus and hardness than the PP/PE/PP and CC/PE/CC separators when measured with nanoindentation.

Gap bridging in laser welding of EN AW 5083 with different joint configurations via beam oscillation and filler wire

The extended use of laser welding in the industry requires a less sensitive process in terms of geometrical tolerances of the joint edges. As the industrial availability of laser systems increases, the demand to use laser welding technology possibly with parts coming from less precise production steps is increasing. Gap formation is often caused by the edge quality of the parts coming from previous manufacturing steps such as sheet forming. Al alloy sheets deformed to box-shaped 3D forms often require welded joints on the edges in lap, but, and corner joint configurations. These joints are hard to carry out by laser welding due to the large gap formation caused by the tolerances of the deformation processes involved. Laser welding of Al alloys is already challenging in the absence of gap formation, while these joint configurations have been not feasible with a stationary beam due to incomplete fusion and defect formation. Laser welding with beam oscillation and wire feeding can improve the weldability of these joints. The oscillating motion of the high-intensity beam can achieve a deep weld together with a wider seam. Combined with wire feeding, the process can close gaps in the butt, lap, and corner joint configurations. On the other hand, the added oscillation and wire-related parameters require extending the experimental space, which requires a methodological study to identify feasible conditions. Accordingly, this work proposes a methodological approach to identify and set laser welding process parameters with beam oscillation and wire feeding for an EN AW 5083. Process parameters were initially studied using a simple analytical model that depicts the beam trajectory. Bead-on-plate tests were conducted to assess beam size, power, and weld speed ranges. Lap, butt, and corner joint conditions with a 0.5-mm gap were welded with high quality by manipulating the laser power, oscillation amplitude, and wire feed rate. The results show that welding speeds could be maintained as high as 55 mm/s with complete filling of gaps of up to 0.5 mm, eliminating the surface undercuts and achieving weld widths in the order of 2.5 mm. Moreover the results show the possibility control the depth of the welds from 3 mm to full-penetration conditions.

Towards Rational Design of Battery Formation Protocols: From Electrochemical Modeling to Factory Deployment

In battery manufacturing, the formation process is both paramount and problematic. It is paramount since all batteries undergo formation charging and aging steps to build a resilient solid electrolyte interphase (SEI) and to screen for defects. It is problematic because the formation process is expensive to operate, remains a major source of factory energy demand, requires larger factory footprints, and takes an order of magnitude longer than nearly every other manufacturing step. Despite the centrality of the formation process in battery manufacturing, steps taken to optimizing formation protocols remain ad-hoc in the absence of design principles and physical models.We highlight recent progress in developing a principled understanding of the SEI formation process applied towards industrial battery formation process (i.e. in the context of a full cell). We review a reduced-order electrochemical model of the formation process that captures first cycle charge dynamics and subsequent cycling and aging degradation behavior [1]. The model predicts measurable quantities such as first cycle efficiency (FCE) and irreversible thickness growth under multiple formation protocols. We discuss opportunities to integrate the electrochemical formation model with differential voltage analysis (DVA) to visualize the connection between first cycle charge dynamics from the perspective of shifting electrode stoichiometries [2] and comment on applications towards physics-informed battery lifetime prediction [3]. We finally share recent data elucidating the effect of formation temperature, pressure, and protocol on cycle life.

Advancements in Dry Coating for Battery Electrodes: Scalable Extrusion Mixing for Control of Electrode Microstructure and Electrochemical Performance

Dry coating of battery electrodes is emerging as a promising alternative technology to the prevailing slurry coating and drying process widely adopted in the lithium-ion battery industry.1,2,3 To date, the most energy-intensive step in cell manufacturing is the drying of slurry-coated electrodes,1 and the adoption of dry coating aims to mitigate both the environmental impact and production costs associated with electrode production. Beyond environmental and economic concerns, producing higher mass-loading electrodes, a crucial aspect for increasing cell energy density, faces inherent challenges with the slurry-coating process: the drying of thick coatings often leads to issues such as electrode cracking and the formation of inhomogeneous electrode microstructures.Bühler and Empa have collaboratively developed and are in the process of scaling up a dry-coating manufacturing method.4 Our process centers around the extrusion mixing of electrode components, followed by calendering of the dry mixture to produce the final electrode and direct lamination onto a current collector. In this presentation, we showcase the adaptability of extrusion mixing in inducing shear fibrillation of polytetrafluoroethylene (PTFE) binder, crucial for achieving the desired electrode microstructures (see Figure 1a and 1b). Furthermore, we demonstrate the capability of our dry-coating technology to produce high-mass loading electrodes with areal capacities of 5 mAh cm-2 or more (see Figure 1c).The presentation encompasses a thorough characterization of dry-coated electrodes, including their microstructure and electrochemical performance in lab-scale batteries. Key aspects, such as rate capability and capacity retention, are evaluated. A comprehensive comparison with slurry-coated electrodes, fabricated using identical active electrode materials, mass fractions, and mass loading, reveals that our dry-coated electrodes exhibit comparable performance to their slurry-coated counterparts.5 The scalability of our dry-coating technology is underscored, highlighting the achievable throughputs necessary for gigafactory-scale production with a single extruder.

Elucidating the Electrochemical Impact of the Calendering Process on Three-Dimensional Designed Electrodes for Lithium-Ion Batteries

Significant advancements in battery technology are imperative to meet the ambitious demands for electromobility and stand-alone energy storage devices. This stems from the need to achieve operations with high energy and power density, coupled with stringent safety standards and extended lifespans, while reducing production and material costs. The preferred energy storage technology for the coming decade is anticipated to remain lithium-ion battery (LIB) technology. The focus on researching high-energy active materials to optimize this technology is paramount. In addition to optimizing materials, significant performance enhancements can be achieved by using electrodes with high mass loading and a multiscale tailored electrode design that can be scaled up to production level.The technological challenges of achieving a breakthrough in gaining simultaneously high energy and power density characteristics while maintaining high process and operational reliability with significant cost savings are the subject of current research and development in the field of LIB technology. To tackle this, the study explores the laser-assisted generation of three-dimensional (3D) electrode architectures and assesses its impact on battery performance and future integration into battery production. The advanced electrode design involves micro and sub-micron structures that can be tailored in various ways, leading to notable improvements in battery lifespan, battery safety, and fast charging and high-power operation capabilities compared to batteries with conventional two-dimensional (2D) electrodes. High-power ultrafast laser ablation emerges as a precise method for introducing such structures.Coordinating the production of 3D electrodes with laser assistance necessitates synchronization with established manufacturing steps in the battery production process. Notably, the calendering of electrodes holds significance due to its substantial influence on the microstructural properties of the electrode material, encompassing porosity, material density, and layer adhesion. The study investigates the impact of laser-induced structuring, encompassing micro-/nano-porosities and microtopography, on electrodes with varying mass loadings ranging from 2mAh/cm² to 6mAh/cm². Electrochemical characteristics such as high-rate capability, fast charging, and cycle lifetime are evaluated accordingly, employing cells with graphite anodes and lithium-nickel-manganese-cobalt oxide cathodes.