bluuebunny/crossref_metadata_2025 huggingface dataset:
Recovery of Cobalt from Lithium-Ion Batteries Using Fluidised Cathode Molten Salt Electrolysis
Authors: Mirza Mateen , Abdulaziz Rema , Maskell William C. , Tan Chun , Shearing Paul R , Brett Dan
Published: July 2022

Within the next 30 years, the number of vehicles powered by electricity is predicted to rise to 1 billion representing an exponential increase from 7.9 million used in 2019 [1]. These electrified vehicles will rely on lithium-ion rechargeable batteries with projections augmented by the impending ban on new petrol and diesel car sales. Despite these batteries offering a green, carbon-free alternative they remain overshadowed by the sustainable use of raw materials. Thus, the future need to recycle enormous quantities of Li-ion batteries arises because of the projected increase in the electrified fleet of vehicles required to decarbonise the transport sector. Cobalt is an essential element in several Li-ion battery cathode chemistries (e.g. NMC, NCA and LCO). In this study, we present an electrochemical reduction process of LiCoO2 to Co using a molten salt fluidised cathode technique at 450 oC [2]. Using thermodynamic calculations, a predominance diagram was constructed in Figure 1 to aid in understanding the reduction pathway. Cyclic voltammograms indicate two 2-electron transfer steps, the first where Co3O4 is reduced to CoO at −0.55 V vs Ag/Ag+ followed by the second reduction step of CoO to Co at −2.4 V vs. Ag/Ag+. The reduction potential of Co was used to determine the input parameters in the current versus time profiles. The Faradaic current efficiencies for both the commercially obtained LiCoO2 and spent Li-ion battery yield values greater than 70%. Thus, the fluidised cathode technique could prove to be an energy-efficient and high-throughput route for the recovery of cobalt, in this work, as well as different materials found in other batteries.

Gielen, R. Gorini, N. Wagner, R. Leme and G. Prakash. International Renewable Energy Agency (IRENA), Global Renewables Outlook: Energy Transformation 2050, Abu Dhabi, Edition: 2020.

M. Mirza, R. Abdulaziz, W.C. Maskell, C. Tan, P.R. Shearing, D.J.L. Brett, Recovery of cobalt from lithium-ion batteries using fluidised cathode molten salt electrolysis, Electrochim. Acta. 391 (2021) 138846.

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Recycling of Lithium-Ion Battery Materials Using Deep Eutectic Solvents
Authors: Ma Chunyan , Gamarra Jorge , Svärd Michael , Younesi Reza , Forsberg Kerstin
Published: July 2022

To drive the transition to a climate-neutral economy, industry will need a sustainable and secure supply of key technology metals, which are essential for large-scale renewable energy production and storage as well as the electrification of mobility. Lithium-ion batteries (LIBs) play an increasingly important role for various energy storage systems. The current and future LIB technologies will require materials that are predicted to have a high supply risk in the future. In light of this, recycling has been put forward as a key strategy next to primary mining and critical raw material substitution.

Great efforts are currently being made to develop smart and sustainable processes for recycling LIB materials from end-of life batteries and production scrap. Lithium nickel manganese cobalt oxide (NMC) and lithium cobalt oxide (LCO) are two common LIB electrode materials. Deep eutectic solvents (DESs) are considered as green solvents in recycling of LIB materials due to their biodegradability and low toxicity combined with good leachability of metal oxides.

In this work, a new process for recycling and direct re-synthesis of NMC111 and LCO is presented. The process is based on leaching using a sustainable DES. Water is used as cosolvent to tune the properties of the DES. Leaching kinetics and mechanisms are determined. The chosen DES shows excellent leaching ability and fast leaching rate at low temperature compared with those DESs reported in the literature. After the leaching step, a new approach is applied to recover the metals from the DES leachate. This approach shows an overall high recovery efficiency and the solid product proves to be a good precursor for direct re-synthesis of new electrode materials. To conclude, this work presents a novel, green, effective and closed-loop metal recovery strategy for recycling LIB materials.
Characterization of Used A123 LiFePO4 Cells from a Hybrid-Bus Battery Pack
Authors: Ramirez-Meyers Katrina , Whitacre Jay
Published: July 2022

As the battery market grows, developing a battery waste management economy becomes imperative. After primary use, the main options for discarded batteries are recycling, refurbishment, reuse, or disposal. Recycling involves extracting valuables materials from ground-up battery cells, while reuse and refurbishment involve direct use of packs or their components, with or without maintenance adjustments. Recycling and disposal are the most common battery waste pathways, while reuse and refurbishment practices require further understanding of battery degradation before being implemented on a large scale. Furthermore, relatively high recycling costs are motivation to pursue more cost-efficient recycling methods like direct recycling.

This work expands on previous studies on the statistical distribution of the state-of-health (SOH) of used LiFePO4 (LFP) cells extracted from a hybrid-bus battery pack.1 We characterize samples from used and pristine A123 M1-A and M1-B 26650 cells using XRD and SEM. We will compare the cell materials’ morphologies and structure to their electrochemical performance in two diagnostic tests: a constant-current cycling test and an electrochemical impedance spectroscopy test.

Preliminary data have been collected from used M1-A cells that demonstrated starkly different states-of-health during electrochemical testing—ranging in residual capacities from 2.2 Ah to 0.30 Ah. The low-SOH M1-A cell had severe anode delamination and morphological cracks in the center of the cylinder cross-section. Cathode delamination in the cell also increased towards the center of the cylinder. The high-SOH M1-A cell’s electrodes had a consistent morphology throughout the cell, but delamination was worst at the center of the cylinder’s cross-section.

In this presentation, we will summarize our x-ray diffraction and scanning electron microscopy data for the cells described in Table 1. We will also discuss technical pathways for direct recycling of active materials from LFP battery waste.

Ramirez-Meyers and J. Whitacre. “(Invited) Statistical Distribution and Feasibility for Re-Use of A123 LiFePO4 Cells from a Hybrid-Bus Battery Pack.” ECS Meeting Abstracts, no. 6, p. 1052. IOP Publishing, 2020.

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The Role of Cathode Surfaces in Lithium-Ion Battery Direct Recycling
Authors: Montoya Anthony , Polzin Bryant , Vaughey John T.
Published: July 2022

Over the past decade the need for new sources of LIB raw materials has become apparent as the market for EVs and other consumer electronics that utilize lithium-ion batteries (LIB) has grown immensely. One emerging source of these needed materials is from the recycling of previous generation LIB cells and devices. Presently, this area is dominated by pyroprocessing and hydroprocessing. As delivered to the manufacturer these processes deliver simple salts or precursors that allow the recovered metals to be re-inserted into the LIB cathode synthesis process at a similar stage to newly mined materials. However, by reducing the end of life cathodes completely to either a metal or simple salt much of the previous investment in cathode creation has been eliminated. Direct processing is a method under development that maintains the integrity of the cathode lattice but seeks to repair the damage done by years of electrochemical cycling and restore the cathode to a near-pristine state. In this talk we will be discussing our work understanding the steps necessary to restore the recovered end of life cathode, assessing the damage done during cycling, and review various methods postulated to achieve this goal. Specific areas discussed will include methods of relithiation, role of surface damage, and role of precursors chosen.
(Digital Presentation) Printed Wearable Electrochemical Sensor for Monitoring Human Performance Markers during Human Spaceflight
Authors: Cordeiro Milton , Koehne Jessica E.
Published: July 2022

Additive manufacturing technologies are being explored by NASA for the in-space manufacturing of sensors and electronics. Additive manufacturing directly addresses the logistic challenge for long-duration human spaceflight missions while also offering a high degree of customization and tailorability. To ensure the health and safety of crew members during long duration missions, it can be advantageous to develop human health diagnostic tools that can be manufactured during those missions. Here we report the development of a wearable and fully printed electrochemical sensor for the detection of human performance markers in sweat.1 The sensor’s fabrication is complimentary with in-space manufacturing for an on-demand and hands-free fabrication and is comprised of commercial and custom carbon, gold and silver inks on a polyimide substrate to make a flexible, 3-electrode electrochemical sensor, shown in Figure 1. Sensor readout is performed using standard electrochemical procedures via a miniaturized, custom potentiostat. The initial prototyped printed electrochemical sensors demonstrate good electrochemical performance and high mechanical stability while also displaying low batch to batch variability. Our goal is to create a highly adaptable and versatile approach that utilizes fabrication processes consistent with in-space manufacturing, thus enabling the manufacture of point-of-care devices during flight.

Reference

Brasier, N. & Eckstein, J. Sweat as a Source of Next-Generation Digital Biomarkers. Digit. Biomarkers
3, 155–165 (2019).

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3D Printable Reservoirs for Potentiometric Analysis of Solid Samples
Authors: Glasco Dalton Lee , Bell Jeffrey Gordon
Published: July 2022

Potentiometric sensing has shown to be highly effective for diagnostic testing of many important ionic biomarkers. Outside of biological analytes, ion-selective electrodes (ISEs) have been utilized for environmental and forensic analytes due to their high specificity and sensitivity. Unfortunately, many samples to be analyzed (especially in the case of forensics) are solids (e.g., powders, soils, etc.) which require sample preparation steps prior to analysis. In this work, we further expand on the utility of fabricating ISEs through 3D printing protocols by developing a sampling reservoir and placing it in contact with the sensing element of potentiometric sensors (i.e., the ion-selective membrane (ISM). This reservoir works as a sampling well, dissolving solid samples and allowing the ions to diffuse to the ISM for quantification.
(Digital Presentation) Soft Robot for Heat Source Detection Using Shape Memory Gel
Authors: Aoyama Hibiki , Ogawa Jun , Watanabe Yosuke , Shiblee Nahin Islam , Khosla Ajit , Kawakami Masaru , Furukawa Hidemitsu
Published: July 2022

Currently, there are Collaborative robots (cobots) that use multiple robots to solve a single, simple task, such as finding survivors in rubble or monitoring the environment during a disaster. [1] Such robots are moved by vibration motors and communicate with nearby robots via infrared communication for control.

In this study, we develop a soft robot that can search for heat sources and solve simple tasks using only a simple structure without any sensors. This soft robot can move by simply vibrating and has a mechanism to switch its motion mode when the temperature of the ground surface or the air changes. The robot is equipped with shape-memory gel [1], which softens and increases the friction rate as the temperature rises, and hardens and decreases the friction rate as the temperature decreases. The shape-memory gel has the property of remaining stationary when the temperature on the ground or in the air rises, and operating when it falls. In our experiments, we measured the absorption of vibration, friction rate, and tackiness in order to verify the effectiveness of controlling the motion of the shape memory gel by temperature. It was confirmed that the vibration was absorbed when the shape memory gel became warm and soft. In the measurement of friction rate and tackiness by temperature, it was confirmed that both friction rate and tackiness increased by increasing the temperature. As a result, the effectiveness of the shape-memory gel was confirmed by temperature. Next, we fabricated a soft robot as shown in Fig. 1 and conducted experiments to see if its motion changed depending on temperature. In the future, we will conduct experiments to see if the soft robot can be used to solve simple tasks such as transporting plants to sunlight.

Reference:

[1] Michael Rubenstein, Christian Ahler, Radhika Nagpal Kilobot, “A low cost scalable robot system for collective behaviors” 2012 IEEE International Conference on Communications (ICC)https://ieeexplore.ieee.org/document/6224638

[2] Ahmed, Aamir, Sandeep Arya, Vinay Gupta, Hidemitsu Furukawa, and Ajit Khosla. "4D printing: Fundamentals, materials, applications and challenges." Polymer (2021): 123926. https://doi.org/10.1016/j.polymer.2021.123926

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Electrochemical Impedance Spectroscopic Investigations of Nanocomposite Thin-Film Formation at an Electrified Micro Liquid-Liquid Interface
Authors: Moshrefi Reza , Stockmann Talia Jane
Published: July 2022

Herein, the interface between two immiscible electrolyte solutions (ITIES) has been exploited as a pristine platform for electropolymerization of the 2D and 3D nanocomposite materials, i.e., metal nanoparticles (NPs) embedded within a conductive polymer matrix that are electrogenerated/electropolymerized simultaneously The free-standing conductive thin film can be prepared with an adjustable loading of metallic NPs, to be tailored for a variety of applications, including as catalytic electrodes in fuel cells, or act as a bioreceptor in a biosensor. Electrochemical impedance spectroscopy (EIS) has been used to investigate mechanistic aspects of film growth through two types of charge transfer processes, ion and electron transfer, that occur during electropolymerization. The thermodynamics of a heterogeneous electron transfer (HET) between redox centers, KAuCl4(aq) and terthiophene (TT, org), across the interface governs the electropolymerization reaction, including the rate, which is itself affected by the rate of diffusion of reactants toward the interface, ohmic resistance of the two electrolyte solutions, distance between reactants due to arrangement of ions at the interface, and reorganization energy of the involved species in the reaction. Electropolymerization is controlled through application of an applied external potential difference and monitored voltammetrically as well as by EIS. Curve fitting of EIS data was performed using an equivalent circuit incorporating a phase constant element (CPE) parallel to a resistor for non-ideal interfacial capacitance, and HET resistance across the film as it forms at the ITIES. Next, those elements are parallel to a resistor (R), and a Warburg element (W) to approximate ion transfer across the ITIES/porous thin-film as it grows (Fig. 1). Data suggest that the films electronic conductivity improves with increasing the [TT]:[KAuCl4] ratio. Increased capacitance was hypothesized to be linked to an increase in the effective surface area of the polymer film during its growth phase versus the molecularly smooth ITIES. Higher [TT]:[KAuCl4] ratios elicited higher capacitance as well as diffusion resistance which can be attributed to formation of a more compact film structure. Cyclic voltammetric and potential step methods are compared and discussed, highlighting the formed films final properties, including film thickness and conductivity.

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(Keynote, Digital Presentation) Commercial Opportunities for Unusual Micro/Nanoscale Semiconductor Technologies
Authors: Rogers John
Published: July 2022

Recent advances in materials science and manufacturing methods establish the foundations for technologies that embed large, addressable arrays of micro/nanoscale semiconductor components distributed on unusual substrates, from plates of glass to sheets of rubber. The results create interesting opportunities for devices with applications that span consumer gadgetry and home entertainment equipment to advanced medical wearables and neurotechnologies for neuroscience research to hardware for brain-machine interfaces. This talk summarizes the key ideas and the current technology status, with various examples of current and future products.
Design of Carbon Nanomaterials for Energy Applications
Authors: Bekyarova Elena
Published: July 2022

Carbon nanomaterials have attracted significant academic and industrial interest as promising candidates for the development of batteries with enhanced capacity and charging capabilities. This study presents the design of graphene materials with capacity beyond 1,000 mAh/g. The graphene materials were chemically modified for enhanced capacity and the structure was engineered for fast ion transport. The materials were optimized for the fabrication of anodes for lithium ion batteries. The graphene anodes were assembled in full cells with Nickel-Manganese-Cobalt (NMC) cathodes in both coin and pouch cell configurations. The performance of the graphene batteries was verified using charge-discharge tests at different current density ranging from C/5 to 10C. The developed graphene batteries demonstrated energy density of 400 Wh/kg at 1C and exceeded 250 Wh/kg at 10C. The power density ranges from 250 to 2,500 W/kg. The batteries showed good cycling stability and retained their energy density for 500 cycles at 1C. The batteries have reduced footprint because of the increased graphene anode density, which exceed two times that of graphite. The competitive advantages of the developed technology are high gravimetric and volumetric energy densities (light, small footprint), high power density, safe operation, fast charging, and long cycle life. The processes are scalable and can be tailored for conformable batteries.

Acknowledgement: Carbon Solutions Inc, acknowledges support under the SBIR programs of Army and Air Force.
(Invited) Nanotechnology for Industrial Electrochemical Energy Storage
Authors: Nazar Linda
Published: July 2022

Nanomaterials are expected to play important roles in the realization of our future society, expected to contribute to the realization of a sustainable society through ensuring smart materials to enable sustainability of water, air, and materials; and energy materials and devices to enable renewable energy production and energy saving. These have enormous industrial/commercial ramifications.

Our society needs to mitigate or ideally reverse global climate change caused by anthropogenetic CO2 emissions resulting from our fossil-fuel-fed society. Electrification, which encourages and enables a circular society is an important part of the solution. It leads to urgent needs for new nanotechnologies and nanomaterials for improved solar cells, batteries, electrolyzers, and the fuel cell components that are needed to support a hydrogen economy. As a prime example, Li-ion batteries, for which the Nobel Prize was awarded in 2019, are the most popular rechargeable batteries today and have become the main power source not only for everyday needs such as portable electronic devices but also for larger-scale applications that will become indispensable society in the very near future.

Although enormous effort has been devoted to improving the electrochemical performance of a large number of Li-based materials, today’s rechargeable batteries have energy densities that remain below theoretical values, and still have far-from-optimal longevity and safety. None of the current rechargeable batteries can meet all the challenging requirements for our energy-storage needs, so the race is on to develop next-generation Li-based systems that encapsulate the desired characteristics of high energy density, low cost, and improved safety. Success in this arena would have tremendous impact on a wide range of technologies ranging from EVs (land and marine), to drones, airplanes, robots, and grid-scale energy storage.

The use of nanotechnology─which has progressed tremendously and continues to establish new ground─is vital to address the significant challenges that next-generation batteries present. These materials challenges remain whether the batteries operate on the basis of typical intercalation chemistry or conversion chemistry. Some of these challenges -as will be covered in this presentation - lie in the development of (a) nanomaterials that can withstand significant volume changes and bond rearrangements during conversion redox reactions, (b) nanocoatings that form protective layers on either the positive or negative electrode to stabilize the electrode–electrolyte interface at either high or low voltage, and (c) nanotechnologies to engineer solid–solid interfaces in all-solid-state batteries. Nanotechnology enables materials scientists to bring novel functions to all battery components that cannot be achieved by conventional approaches. This topic will be the central focus of this presentation.
(Digital Presentation) Graphenated Carbon Nanotube Based MEMS Supercapacitors
Authors: Wang Dan , Hall Timothy , Inman Maria , Taylor E. Jennings , Bento Serpa Rafael Bento , Parker Charles B. , Glass Jeffrey T.
Published: July 2022

The inherent advantages of MEMS (micro-electromechanical system) technology, including small size and cost-effective fabrication, make it ideal for numerous applications in a wide range of industries ranging from defense, automotive, medical, to consumer industries. For applications that require self-powered MEMS electronics, an integrated energy storage device is required. Due to their small size, excellent cycle life and high-power density, miniature supercapacitors are an excellent choice for such an integrated energy storage device. The development of electrode materials and electrode fabrication processes for supercapacitors are thus critical for the practical applications of MEMS technology in electronics.

In this presentation, Faraday Technology Inc. and Duke University will discuss a novel 3D graphenated carbon nanotube (g-CNT) network with pseudocapacitive coatings as the electrode materials for fabricating high energy density MEMS supercapacitors. The g-CNT has a high surface area three-dimensional framework of the CNTs coupled with the high edge density of graphene (Figure 1 A), which represents a potential maximum in both charge density and surface area, and thus provide the enhanced capacitance.

An innovative electrophoretic deposition (EPD) manufacturing process, based on the use of pulsed electric fields, has been developed for controlled, reproducible, and scalable deposition of g-CNTs on interdigitated electrodes (Figure 1 B). In addition, pseudocapacitive coatings (such as MnO2) have been electrodeposited on the g-CNT coated electrode to further increasing supercapacitor energy density. Figure 1 C shows no redox peaks, which is important for using this structure as a supercapacitor application. The square shape of the cyclic voltammogram shows that ions experience free flow through the 3-D g-CNT structure. The Charge/Discharge curves (Figure 1 D) indicate the areal energy density of g-CNT/MnO2 coated electrodes (either 50 or 100 cyclic voltametric deposition cycles) are 45 and 93 times higher than g-CNT coated electrodes, respectively.

In summary, a scalable manufacturing process for fabricating g-CNT network with pseudocapacitive coatings as electrodes has been demonstrated and shown great potential in producing high energy density MEMS supercapacitors for energy harvesting applications.

Acknowledgements: The financial support of DOD DMEA STTR program through grant No. HQ0727-21-P-0029 is acknowledged and National Institutes of Health under award number 1R21EY031271 is acknowledged. The information, data, or work presented herein was funded in part by National Aeronautics and Space Administration under Grant No. 80NSSC19K1027, the views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

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(Invited) All-Carbon Nanotube Photovoltaic Device Employing Energy Hierarchy
Authors: Oyibo Gideon , Barrett Thomas , Jois Sharadh , Blackburn Jeff , Lee Ji Ung
Published: July 2022

The use of an energy funnel or hierarchy to efficiently transfer photoexcitations is not new. In photosynthetic systems, whether in plants, algae, or photosynthetic bacteria, to achieve high efficiency, special light-harvesting protein complexes convert sunlight to excitons. High efficiency is achieved by temporarily storing excitons in these complexes before shuttling them to the reaction center where the conversion to usable energy takes place. For added efficiency, photosynthetic systems have adopted an energy hierarchy that funnels excitations from the light-harvesting complexes to the reaction center.

The use of an energy funnel to increase the efficiency of photovoltaic devices, however, has not been widely adopted, due in part to limited materials compatibility and energy landscape. An energy funnel can absorb over a broad solar spectrum while minimizing the volume of material needed to construct a device, which can reduce the dark leakage current. Carbon nanotubes (CNTs) provide an ideal system to explore this new feature since a single material system can provide a wide range of energy levels. Depending on the diameter, excitonic levels in CNTs span from the visible to near-infrared spectrum. Furthermore, the device design can take advantage of the high aspect ratio of CNTs, to efficiently transport both free carriers and excitons along the nanotube.

Here, we describe our efforts to develop photovoltaic p-n diodes using energy hierarchy. We use a network of CNTs in a p-n junction configuration where the transport is mostly along the CNTs. To form the p-n junction, we use buried split gates that are biased independently to form the p- and n-doped regions. The use of split gates is an extension of our earlier studies on single CNT p-n diodes.

We use different chirality CNTs to implement the energy hierarchy. Specifically, the network is structured to funnel excitons by placing larger bandgap semiconducting nanotubes on top of smaller bandgap CNTs. We discuss features that show enhanced exciton to photocurrent generation in these devices compared to devices without the energy hierarchy.
Facile Transformation of Waste Biomass into Nitrogen-Doped Graphene for Highly Efficient Metal-Free Electrocatalyst for the Oxygen Reduction Reaction
Authors: Shah Asmita , Kim Youngki , Singh Dharmendra Pratap
Published: July 2022

Key words: Metal-free catalyst, Oxygen reduction reactions, Pyridinic nitrogen, Stability

It is of significant interest to produce metal-free electrocatalysts for oxygen reduction reactions (ORR) derived from low-cost and environmentally friendly biomass. This work presents a facile thermal annealing approach for large-scale synthesis of the nitrogen-doped graphene (N-GO) nanoflakes using melamine as the nitrogen source and chestnut shells-based biomass as the carbon source. This approach allows us to achieve a high nitrogen doping level in graphene. Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared spectroscopy (FTIR) were used to characterize the N-GO. XPS analysis revealed the presence of pyridinic, graphitic, and pyrrolic nitrogen doping in graphene sheets, with pyridinic nitrogen being the most abundant. Electrochemical investigations showed that a higher concentration of pyridinic nitrogen configurations contribute significantly to the superior electrocatalytic activity toward oxygen reduction reactions (ORR) in alkaline electrolytes. The as-synthesized N-GO exhibits high ORR activity with the onset and half-wave potential of 0.90 V and 0.79 V in alkaline medium, respectively; which is among the best reported to the date for metal-free catalysts. Moreover, compared with the commercial Pt/C, optimized N-GO electrocatalyst exhibits more positive onset potential and better long-term stability, making it a promising metal-free catalyst for practical fuel cells.

Acknowledgements: The authors are thankful to Campus France and the National Research Foundation of Korea for financing the PHC Star mobility project (45823YC).

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(Invited) Microstructural Design Principles for Achieving Stable Electrochemical Interfaces for Metal Anodes
Authors: Mitlin David
Published: July 2022

Lithium metal battery systems (LMBs) are being sought as an ultimate replacement to LIBs, potentially increasing the cell energy by over fifty percent due to the high capacity and low voltage of the metal anode. Analogous improvement in energy is possible with sodium metal batteries (NMBs) and with potassium metal batteries (KMBs), where existing ion insertion anodes can be replaced by plating/stripping metal. However, in all three cases safety and performance are compromised by an unstable solid electrolyte interphase (SEI) that consumes metal ions and electrolyte, and ultimately leads to dendrites. This presentation provides a series of case studies derived from the group's LMB, NMB and KMB research on the microstructural design principles that provide for long-term cycling and fast-charge stability of metal anodes. The approaches may be categorized as the following: a) design of plating/stripping supports and templates with tuned geometry and functionality; b) design of secondary interlayers placed between the metal anode and the separator; and c) design of multifunctional hybrid separators to replace the conventional polymer separators employed with LIBs. It is demonstrated that despite appearing distinct, the efficacy of each in enabling electrochemical stability originates from three fundamental features that are directly interrelated. The wetting behavior of the electrolyte on the anode must be optimized, the wetting/stripping behavior of the metal anode on the current collector must be controlled, and a geometrically and chemically modified SEI must be established. Simultaneously achieving all three leads to stable plating/stripping, while missing even one leads to rapid dendrite growth. Cryogenic FIB cross sections and cryo-TEM are combined to yield new insight regarding film wetting behavior and early dendrite formation in optimized versus baseline specimens, analyzing growth in several representative electrolytes.
(Invited) Tunable Large-Scale Compressive Strain Sensor Based on Carbon Nanotubes/PDMS Foam Composites By Additive Manufacturing
Authors: Le Linh , Ding Junjun , Liu Chao , Zhang Mingshao
Published: July 2022

The compressive strain sensor is widely used as stretchable electronic, human motion detector, and health monitor due to its ability to convert large-scale mechanical deformation to the electrical signal. Carbon material reinforced polymer matrix composites are extensively studied to fabricate the strain sensor. However, there is a challenge to tune the performance of the strain sensor due to the fixed composition of the composite. In this work, we fabricated a carbon nanotube (CNT)/ polydimethylsiloxane (PDMS) compressive strain sensor with tunable mechanical and electrical performance. CNT was used as the reinforcement material due to its excellent electrical conductivity. PDMS was used as the matrix material because of its non-toxicity and flexibility. The foam structure created by the sacrificial sodium chloride (NaCl) allowed the compressive strain sensor to obtain at least 50% strain deformation. The material extrusion 3D printing (ME3DP) method was used to fabricate the complex scaffold structure due to its advantage of free design. The compressive strain sensor had a maximum gauge factor of 17.4 and work stably for at least 10000 cycles. The strain sensor was used to detect both large- and small-scale human motions due to its adjustable composition and sensitivity. We believe our method of building CNT/PDMS strain sensor with tunable performance broadens the potential on the fabrication of flexible electronic devices. Our method of using additive manufacturing to form the model also expends the routes of fabrication in a more flexible design and cost-saving method.
(Invited) DNA Sequencing with Carbon Nanotube Electronics
Authors: Collins Philip G
Published: July 2022

Nanoscale materials and devices provide new opportunities to monitor and understand biomolecules. This presentation will review novel devices in which single molecules of DNA polymerase have been joined to single-walled carbon nanotube (SWNT) transistors.

DNA polymerases are the enzymes that convert single-stranded DNA into double-stranded helices. This biochemical process is the primary step in DNA replication, amplification, and most sequencing technologies. When one of these polymerases is attached to a SWNT transistor, the enzyme’s native activity is simultaneously transduced into a high-resolution electrical signal [1]. Each time the enzyme works its way down a DNA strand, it generates a nucleotide-by-nucleotide signal that encodes the DNA sequence.

This hybrid, biofunctional device is the key element for developing a new, electronic DNA sequencing technology. As a solid-state, manufacturable element, the SWNT transistors provide exciting possibilities for high-density, high-throughput, and low cost sequencing solutions. In addition, the technique is easily generalized to DNA polymerases with specialized properties. Proof-of-principle measurements have been accomplished with DNA polymerases from five different organisms, including the highly processive polymerase of φ29 phage and the high-temperature polymerase Thermus aquaticus (Taq), which is the foundation of the polymerase chain reaction (PCR) and commercial DNA amplification. The SWNT transistor technique operates equally well at room temperature and the elevated PCR temperature of 72 °C, which opens opportunities for novel, high-temperature sequencing strategies with Taq or similar thermostable polymerases.

[1] T. J. Olsen et. al., JACS
135, 7855 (2013); O. T. Gul et. al., Biosensors
6, 29 (2016)
Carbon Nanotube Quantum Defect Photoluminescence Modulation for Biosensors
Authors: Heller Daniel A. , Kim Mijin , Chen Chen , Yaari Zvi , Frederiksen Rune , Heller Daniel , Wang Peng , Jagota Anand , Zheng Ming , Wang YuHuang
Published: July 2022

Covalent sp3 defects on single-walled carbon nanotubes (SWCNTs), often called organic color centers (OCCs) have been explored for their photoluminescent properties, including the potential for introducing new emission bands, increasing quantum yield, and introducing new chemical sensitivities. The application of OCCs for biomedical applications requires new methods to synthesize them via covalent chemistry, to control their biological interactions/biocompatibility via supramolecular interactions with excipients, and to measure their emission in biological environments. We have found specific utilities of OCCs for the detection of chemical phenomena where SWCNT photoluminescence is normally relatively insensitive, such pH changes in the physiologic range. We developed OCCs to measure lysosomal pH in live cells and in vivo, enabling new biological discoveries. We also developed OCC-based biosensors for cancer detection. We believe that OCCs will facilitate the development of an important class of sensors for biomedical applications.
(Invited) Machine Learning for DNA/SWCNT Based Molecular Perceptron: Finding Sequences and Training Sensor Arrays
Authors: Yang Yoona , Yaari Zvi A , Lin Zhiwei , Heller Daniel A. , Zheng Ming , Jagota Anand
Published: July 2022

Single wall carbon nanotube (SWCNT) based biosensors provide opportunities for building an ultra-sensitive biosensing system due to their unique optical properties and strong sensitivity to changes in the local environment. Consequently, much effort has been made to develop SWCNT-based sensors. However, the usual method is based on one-to-one recognition which is a difficult way to detect a variety of molecules. In this study, we describe a sensing system, which we call the Molecular Perceptron, that uses an array of weakly-specific sensors combined with a machine learning model. We show how machine learning algorithms, along with choice of feature representation, can be used both for discovery of special resolving DNA sequences and to predict presence and concentration of biomarkers. DNA/SWCNT hybrids were utilized to optically detect biomarker analytes by observing changes in the fluorescence spectra of each SWCNT. Using the experimental data, machine learning models were trained using three different algorithms: Support Vector Machine, Random Forest, and Artificial Neural Network. We demonstrated this platform in gynecologic cancers, often diagnosed at advanced stages, leading to low survival rates. We investigated the detection of protein biomarkers in uterine lavage samples, which are enriched with certain cancer markers compared to blood. We found that the method enables the simultaneous detection of multiple biomarkers in patient samples, with F1-scores of ~0.95 in uterine lavage samples from patients with cancer. This work demonstrates the potential of perception-like systems for the development of multiplexed sensors of disease biomarkers without the need for specific molecular recognition elements. We also demonstrated that machine learning models trained on relatively small DNA sequence data sets can very accurately predict new resolving DNA sequences.
(Invited) Real-Time Detection of Insulin Secreted By Pancreatic β-Cells Using Single-Walled Carbon Nanotube Sensors
Authors: Bisker Gili
Published: July 2022

Quantification of insulin is essential for diabetes research in general, and for the study of pancreatic β-cell function in particular. Fluorescent single-walled carbon nanotubes (SWCNTs) find many applications as optical nanosensors for biomolecules, proteins, and enzyme, with real-time feedback on target analyte binding1–4. Herein, fluorescent SWCNT are used for the recognition and real-time quantification of insulin5. Two approaches for rendering the SWCNT sensors for insulin are compared, using surface functionalization with either a natural insulin aptamer with known affinity to insulin, or a synthetic lipid-PEG, both of which show a modulation of the emitted fluorescence in response to insulin. Although the PEGylated-lipid has no prior affinity to insulin, its response to insulin is more stable and reproducible compared to the insulin aptamer-SWCNTs. The SWCNT sensors successfully detect and quantify insulin secreted by β-cells within the complex environment of the conditioned media, and the results are found to be in agreement with an enzyme-linked immunosorbent assay5. This novel analytical tool for real time quantification of insulin secreted by β-cells provides new opportunities for rapid assessment of β-cell function.

(1) Bisker, G.; Dong, J.; Park, H. D.; Iverson, N. M.; Ahn, J.; Nelson, J. T.; Landry, M. P.; Kruss, S.; Strano, M. S. Protein-Targeted Corona Phase Molecular Recognition. Nat. Commun.
2016, 7, 1–14.

(2) Bisker, G.; Bakh, N. A.; Lee, M. A.; Ahn, J.; Park, M.; O’Connell, E. B.; Iverson, N. M.; Strano, M. S. Insulin Detection Using a Corona Phase Molecular Recognition Site on Single-Walled Carbon Nanotubes. ACS Sensors
2018, 8 (2), 367–377.

(3) Amir, D.; Hendler-Neumark, A.; Wulf, V.; Ehrlich, R.; Bisker, G. Oncometabolite Fingerprinting Using Fluorescent Single-Walled Carbon Nanotubes. Adv. Mater. Interfaces
2021.

(4) Wulf, V.; Slor, G.; Rathee, P.; Amir, R. J.; Bisker, G. Dendron-Polymer Hybrids as Tailorable Coronae of Single-Walled Carbon Nanotube. ChemRxiv
2021. https://doi.org/10.26434/ChemRxiv.14452785.V1.

(5) Ehrlich, R.; Hendler‐Neumark, A.; Wulf, V.; Amir, D.; Bisker, G. Optical Nanosensors for Real‐Time Feedback on Insulin Secretion by Β‐Cells. Small
2021, 17 (30), 2101660.
(Invited) Cerebrospinal Fluid Leakage Detection with Carbon Nanotube-Based Field-Effect Transistors
Authors: Star Alexander
Published: July 2022

Cerebrospinal fluid (CSF) leakage is a life-threatening medical condition that could result in significant morbidity and mortality if left untreated. However, the gold-standard test for confirming CSF leakage by detecting beta2-transferrin (β2-Tf) proteins using gel electrophoresis and Western blot is labor intensive and requires 3–6 hours. Carbon nanotube-based field-effect transistors (NTFET) are promising candidates for point-of-care diagnostic devices, owing to the outstanding electronic and mechanical properties of carbon nanotubes. The use of enriched semiconducting (sc) single-walled carbon nanotubes (SWCNT) significantly improves the performance of NTFET devices and enables label-free protein detection. To demonstrate that sensitive and specific detection of β2-Tf in biological fluids can be achieved by using NTFET biosensor platform, we have developed a three-step strategy for β2-Tf detection using NTFET devices. The three-step strategy for β2-Tf detection includes two steps of affinity chromatography to isolate β2-Tf and a rapid β2-Tf sensing step utilizing a high-purity sc-SWCNT FET device. Three different sensing configurations for the sc-SWCNT FET sensor were investigated for obtaining the optimal β2-Tf sensing results. Compared to current methods for CSF leak diagnosis, such as electrophoresis and imaging methods, our three-step strategy can offer high quality CSF leak detection with a short turnaround time (around 1 hour), easy instrument access and simple operations, which could potentially benefit medical treatment of traumatic brain injury (TBI) patients and other people in need. The versatility of our sensing platform could also open opportunities for point-of-care applications for other disease-related protein detection, as we have recently demonstrated by rapid detection of SARS-CoV-2 antigens for COVID-19 testing.
Machine Learning for Carbon Nanotube Optical Sensors
Authors: Heller Daniel A. , Yaari Zvi A , Kim Mijin , Yang Yoona , Chen Chen , Antman-Passig Merav , Wang Peng , Wang YuHuang , Jagota Anand , Zheng Ming
Published: July 2022

Perception-based machine learning platforms, modeled after the complex olfactory system, can isolate individual signals through an array of relatively nonspecific receptors. Each receptor captures certain features, and the overall ensemble response is analyzed by the neural network in our brain, resulting in perception. Previous attempts to develop perception-based sensing platforms include “electronic nose” technologies for gas sensing, based on conducting polymers, DNA-decorated field-effect transistors, and other technologies based on protein recognition using simple data analytic techniques. We developed single-walled carbon nanotube (SWCNT)-based sensor arrays wherein the optical responses of the nanotubes were used to train machine learning models. Due to the existence of several mechanisms of optical modulation of SWCNTs, as well as multiple carbon nanotube species with differing bandgaps, and the increasing number of moieties that can be used for colloidal suspension and functionalization, new methods in data analytics can be used to facilitate selective recognition of bioanalytes to detect and process multi-parametric spectroscopic fingerprints. These methods can improve the detection of biological analytes and to diagnose diseases.
(Invited, Digital Presentation) Application of Polyacid Clusters in Modifying Single-Walled Carbon Nanotubes
Authors: Li Yan
Published: July 2022

Phosphotungstic acids (PTAs) are a typical family of polyacids with tunable composition, structure and morphology. Relying on their super strong acidity and moderate oxidizability, they may take different roles when interacting with single walled carbon nanotubes (SWCNTs).

We found that PTA could be used as stable dopants for SWCNT films to reduce the resistance without damaging the transparency. By simply dipping the SWCNT films in the solution of PTAs and drying afterwards, the sheet resistance was cut in half with long term stability. The doped films showed excellent flexibility. Both Raman spectroscopic studies and Kelvin probe force microscopy measurements revealed that the strong acidity of PTAs plays a key role in the doping effect by increasing the redox potential of the ambient O2 and thus the Fermi level of the SWCNTs is brought down.

The PTA clusters can be encapsulated into the inner cavity of SWCNTs when their diameters are compatible. Such a host-guest molecular interaction between SWCNTs and inner clusters with designed size was applied to separate large-diameter s-SWCNTs. When a kind of PTA of ~1 nm in size were filled within SWCNT cavities, s-SWCNTs with diameters concentrated at ~1.3–1.4 nm were selectively extracted with the purity of ~98% by a commercially available polyfluorene derivative. The sorting mechanisms associate with oxidation effect of PTA and the size-dependent electron transfer from nanotubes to inner PTA clusters. The flexible regulation of interaction between the nanotube and clusters, thus tuning the diameter of sorted s-SWCNTs.

PTAs have shown great power in tuning the properties of SWCNTs, presenting amazing potentials in the applications of SWCNTs.
(Invited) Synthesis and Application of One-Dimensional Van Der Waals Heterostrucures Based on Single-Walled Carbon Nanotubes
Authors: Maruyama Shigeo
Published: July 2022

A typical one-dimensional (1D) van der Waals (vdW) heterostructure consists of single-walled carbon nanotubes (SWCNT), boron nitride nanotube (BNNT), and molybdenum disulfide nanotube (MoS2NT), can be grown coaxially by successive chemical vapor deposition (CVD) steps [1]. The coaxially nested structure based on SWCNTs can expand the board application possibilities of 1D vdW heterostructures [2]. Semiconductor SWCNT wrapped with BNNT can be regarded as the ideal building blocks of field-effect transistors (FET) [3]. We have demonstrated the radial semiconductor–insulator–semiconductor (S-I-S) tunneling heterojunction diode by using a micrometer long 1D vdW heterostructure SWCNT@BNNT@MoS2NT [4]. By comparing optical properties of films of BNNT@MoS2NT and SWCNT@BNNT@MoS2NT, we found strong photoluminescence (PL) from monolayer MoS2NT and quenching of PL by coupling to SWCNT through thin BNNT [5]. The remarkable population of free charges and inter-tube excitons are demonstrated by ultrafast optical spectroscopy [6]. The inter-tube excition is regarded as the inter-layer excition for 2D heterostructures. Precise control of the chemical vapor deposition (CVD) process of each layer is essential since the mechanical exfoliation & stacking technique for 2D counterpart is not possible for 1D vdW heterostructures. The surprisingly sharp edge of BNNT grown on SWCNT is the signature of preference of nitrogen terminated zig-zag edge of h-BN common to 2D counterpart [7]. The next challenge is the CVD growth of various transition metal dichalcogenides on BNNTs. In addition to MoS2 nanotubes [1], we will discuss the growth control of WS2 nanotubes and NbS2 nanotubes. A general strategy we can tune the CVD condition from 2D flake to 1D tube is proposed [8].

Part of this work was supported by JSPS KAKENHI Grant Number JP20H00220, and by JST, CREST Grant Number JPMJCR20B5, Japan.

References

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[2] S. Cambré, et al., Small, 17 (2021) 2102585.

[3] R. Xiang, S. Maruyama, Small Sci., 1 (2021) 2000039.

[4] Y. Feng, et al., ACS Nano, 15 (2021) 5600.

[5] M. Liu, et al., ACS Nano, 15 (2021) 8418.

[6] M. G. Burdanova, et al., Adv. Funct. Mater., 9 (2021) 2104969.

[7] Y. Zheng, et al, P. Natl. Acad. Sci., 118 (2021) e2107295118.

[8] Y. Zheng, et al, to be submitted.