Unraveling the impact of the design of current collector on dry-processed lithium-ion battery electrodes

Abstract Environmental sustainability and the effective use of renewable resources are critical subjects that need to be integrated into our educational systems through practical, hands-on learning. This paper focuses on the fabrication of aluminium-air batteries using waste materials, providing an innovative and cost-effective DIY approach to energy storage education. Utilizing aluminium from food packaging and graphite from pencils, this study demonstrates the construction and functionality of an aluminium-air battery to run an LED, highlighting its potential applications in educational settings and low-cost energy solutions. The paper aims to inspire the adoption of environmentally friendly practices and enhance students’ understanding of electrochemical energy conversion through accessible and engaging DIY projects.

The escalating necessity for more efficient and defect-free joining of ‘ultra-thin foil collectors-to-tabs’ in electric vehicle (EV) Li-ion pouch cells motivates this study. The prevalent ultrasonic welding (USW) method for these joint types, faces limitations such as design constraints and access requirements, laser welding (LW) emerges as a promising alternative offering flexibility, one-side access and faster speeds with efficient heat input. This study aims to investigate the feasibility of LW as a viable alternative to USW for joining current collectors-to-tab joints. It compares the mechanical, metallurgical, electrical and thermal analysis of the joints to evaluate both welding techniques for joint defects. The comparison of solid-state material mixing during USW and the intermixing of aluminium (Al) and copper (Cu) during fusion LW using EDX analysis presents interesting observations in the study. The USW generates a thin transition layer with intermetallic compounds (IMCs) attributed to the diffusion of Cu into the Al matrix during joining, which is comparatively lower as in the case of LW with higher material mixing with brittle IMCs like Al2Cu and Al4Cu9. However, the joint strength of LW is comparatively lower than the USW joint attributed to the reduced fusion zone area. Furthermore, from the electrical contact resistance and the joint temperature analysis, it was found that the resistance and temperature vary by as much as 13% and 6%, respectively, for the 50 A and 75 A passing currents when the USW is replaced with the LW process.

Abstract The present paper describes the ion conduction mechanism and solid-state battery fabrication of a new sodium (Na+) ion-conducting blended solid polymer electrolytes (BSPEs): (1-x) [70PEO:30NaCl] + x PVP where 0 ≤ x ≤ 15 wt.%. A recently established hot-press process has been used to synthesize the present BSPEs. The composition: 98(70PEO:30NaCl) + 2PVP yielded the highest ionic conductivity (σ ~ 3.7×10− 5 S.cm-1). Polymer salt/PVP complexation has been studied with the help of x-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Measurements of ionic conductivity (σ), ionic mobility (µ), mobile ion concentration (n), ionic transference number (tion), and ionic drift velocity (vd) have all been used to elucidate the process of ion conduction. A solid-state polymer battery has been fabricated by using the highest ionic conductivity composition of BSPE. Solid-state battery characteristics have been investigated at room temperature under various load conditions.

The recent interest in microscopic autonomous systems, including microrobots, colloidal state machines, and smart dust, has created a need for microscale energy storage and harvesting. However, macroscopic materials for energy storage have noted incompatibilities with microfabrication techniques, creating substantial challenges to realizing microscale energy systems. Here, we photolithographically patterned a microscale zinc/platinum/SU-8 system to generate the highest energy density microbattery at the picoliter (10-12 liter) scale. The device scavenges ambient or solution-dissolved oxygen for a zinc oxidation reaction, achieving an energy density ranging from 760 to 1070 watt-hours per liter at scales below 100 micrometers lateral and 2 micrometers thickness in size. The parallel nature of photolithography processes allows 10,000 devices per wafer to be released into solution as colloids with energy stored on board. Within a volume of only 2 picoliters each, these primary microbatteries can deliver open circuit voltages of 1.05 ± 0.12 volts, with total energies ranging from 5.5 ± 0.3 to 7.7 ± 1.0 microjoules and a maximum power near 2.7 nanowatts. We demonstrated that such systems can reliably power a micrometer-sized memristor circuit, providing access to nonvolatile memory. We also cycled power to drive the reversible bending of microscale bimorph actuators at 0.05 hertz for mechanical functions of colloidal robots. Additional capabilities, such as powering two distinct nanosensor types and a clock circuit, were also demonstrated. The high energy density, low volume, and simple configuration promise the mass fabrication and adoption of such picoliter zinc-air batteries for micrometer-scale, colloidal robotics with autonomous functions.

Understanding the diffusion dynamics of lithium within solid-state electrodes is pivotal for developing high-performance batteries. In this context, layered oxides were utilized as a promising cathode material due to their high energy density and fast intraparticle lithium diffusivity. Despite advancements in material composition, coating, and doping, the understanding of intraparticle lithium diffusion has long been described by Fick's law. Conventionally, lithium diffusion is assumed to generate a monotonic lithium concentration gradient within solid-solution single-crystalline battery materials during cycling. This raises fundamental questions about diffusion in layered oxides; (1) Can the diffusion of Li in solids be interpreted as Fickian diffusion, similar to diffusion in gases or liquids, even though it involves structural and phase evolution throughout the battery cycle? and, (2) Does the fast diffusivity (10-11-10-9 cm2/s) support the homogenization of Li?In this study, we address these questions surrounding lithium diffusion in layered oxide by utilizing operando scanning transmission X-ray microscopy. We revealed the formation of mobile Li-dense/-dilute nano-domains within individual single-crystalline LiNi1/3Mn1/3Co1/3O2 (scNMC) during battery cycles. We term this phenomenon ‘multi-clustered lithium diffusion’, distinguishing our findings from the conventionally suggested Fickian diffusion model in solid-solution materials. These domains persist for at least 4 hours during relaxation, accompanied by locally residing strained domains, as confirmed by Bragg coherent diffraction imaging (BCDI), within a single particle. We believe these domains arise due to the compensation of localized chemical potential gradients that are generated by the sustained presence of strain within the battery particles during cycling.While maintaining integrity of Li-dense/-dilute domain at various C-rates, STXM result further show that Li-dilute domains maintain during the discharging. Given the lower concentration of Li at insertion boundaries, which could lower the surface charge transfer impedance of the system, Li-dilute domains facilitate lithium transport by functioning as low-resistance pathways. Through a comprehensive analysis of electrical impedance spectroscopy (EIS), STXM imaging and finite element analysis (FEA), we showed that controlling the local domain fraction is crucial for controlling the overpotential during subsequent charging. Our study introduces new insights into nanoscale solid-state diffusion, thereby enabling the fabrication of high-performance batteries. Figure 1

In-situ polymerized acrylate-based polymers are very appealing as solid polymer electrolytes (SPEs) in lithium (Li) batteries due to the drop-in compatibility of such in-situ polymerization with conventional battery production, the ease of acrylate polymerization and their inexpensive, facile SPE chemistry. We identified, however, that such SPEs suffer from either a low cationic transference number with dual ion conducting salts (0.12-0.2) or a low ionic conductivity with single Li-ion conducting (SLIC) salts (6·10-6 S cm-1). In this project we overcame these limitations and developed significantly improved SPE with ionic conductivity of up to 2·10-4 Scm-1 and a relatively high Li-ion transference number of 0.4. With a significantly reduced fraction of mobile anions in the hybrid SPE, in-situ polymerized SPE cells with an LiFePO4 (LFP) cathode achieve a stable performance for over 100 cycles at temperatures as high as 100 °C, which is unattainable with conventional Li salts or electrolytes. Furthermore, the motional narrowing observed in the line-shapes of solid-state nuclear magnetic resonance (SS-NMR) spectra provided additional insights of the differences in Li nucleus environments and revealed a reduced activation energy for the hybrid salt SPEs due to their more open structure. This study opens the path for the fabrication of high-performance solid polymer lithium batteries capable of operating at high temperatures using commercial battery fabrication equipment. We expect that further tuning of the acrylate based SPE composition may allow further increases in its conductivity without sacrifices in its electrochemical stability or mechanical properties.

Hybrid or all-electric aircraft are being developed as the next generation of aircraft to both allow new forms of aviation and decrease environmental impact. Since these types of aircraft are based on high-capacity battery technology, safe operation of these batteries becomes increasingly important. In particular, the potential for battery failure due to uncontrolled chemical reactions resulting in thermal runaway, catastrophic failure, and battery fires must be addressed in order for such battery technology to have the level of safety needed for standard aviation implementation. Efforts to ensure battery safety often involve engineering solutions that seek to contain rather than prevent such events by early detection. Such approaches increase the system weight and decrease the power per unit mass provided by the battery system. Existing methods for measuring battery parameters to determine the battery state-of-health are limited. These methods include electrical measurements of the cell current and/or voltage output as well as temperature measurements taken externally on the cell surface. Such external temperature measurements are limited in their ability to provide early warning of impending battery failure. In response, an effort to develop sensors operating internal to battery for health monitoring has been ongoing in the NASA Sensor-based Prognostics to Avoid Runaway Reactions & Catastrophic Ignition (SPARRCI) project [1]. The basic approach associated with this sensor work is the deposition of thin film sensors on the battery separator located between the anode and cathode of the battery. These thin film sensors are then monitored to determine changes in battery parameters and health. Microfabrication techniques are employed to minimize the overall impact of the sensors on battery operation through the implementation of sensors with minimal size, weight, and power consumption. The thickness of the films, which are fabricated through physical vapor deposition (sputtering), are on the order of thousands of angstroms and can have minimal surface area. Thin film sensors for system health management have been implemented for a many decades on complex components for aerospace applications [2,3]. However, the application of thin films of this type on a battery separator for internal battery monitoring applications has not previously been demonstrated to our knowledge. This paper describes the development of sensors for the internal battery monitoring through the use of thin film sensor technology. Thin metal films were successfully deposited on a battery separator polymer material with good adherence and electrical continuity. Multiple types of sensors have been deposited, as well as lead connections from the sensor to the edge of the separator material. The ability of these thin film sensors immersed in electrolyte to perform multiple types of battery parameter measurements has been demonstrated. For example, a multiparameter sensor system measured multiple properties simultaneously inside of a pouch cell over a wide temperature range. Further, real time measurement of interior temperature changes in a battery pouch cell with an integrated interior temperature sensor was demonstrated. These changes include detecting a fault in the battery (shorting) in situ with rapid response time (less than a minute) corresponding to a more limited response by a temperature sensor mounted externally. Other aspects of monitoring battery health were also explored, such as real-time measurement of simulated dendrite growth/metal deposition by sensor on separator material demonstrated. Future efforts will include improvements in the durability of the sensor structure to allow introduction of the approach into standard battery fabrication techniques. Overall, this work is a step forward in providing a method to prevent catastrophic battery failures and provide a foundation for safer, lighter, and higher energy batteries for the electric aircraft industry.[1] B. DeMattia, Daniel Perey, John Lawson, and Gary Hunter, “Advanced Battery Health Approaches for Electric Aircraft”, Energy & Mobility Technology, Systems, and Value Chain Conference & Expo, Cleveland, OH, Sept. 23, 2023.[2] John D. Wrbanek, and Gustave C. Fralick, “Thin Film Physical Sensor Instrumentation Research and Development at NASA Glenn Research Center”, 52nd International Instrumentation Symposium Cleveland, OH, May 2006, NASA TM-2006-214395[3] Lawrence G. Matus (2015) “Instrumentation for Aerospace Applications: Electronic-Based Technologies”, Journal of Aerospace Engineering 26 (2) https://doi.org/10.1061/(ASCE)AS.1943-5525.0000302

Development of solid-state batteries with a high voltage cathode and lithium metal anode could enable high energy density while avoiding safety issues of flammable liquid electrolytes. However, the solid electrolyte (SE) should meet multiple requirements, including 1) electrochemical stability at both the cathode and anode side interfaces, 2) small thickness (tens of μm) to maximize energy density of the cell, and 3) fabrication with a scalable manufacturing method. Using bilayer SEs with different electrochemical stability windows could enable stability at both cathode|SE and anode|SE interfaces. In this work, we developed a manufacturing process to fabricate thin (60 μm) free-standing bilayer SE films from slurry casting and lamination, which can be used for large scale manufacturing of SSBs.Halide SE (Li3InCl6) and sulfide SE (Li6PS5Cl) were slurry casted on different substrates, and then were dried in vacuum before being laminated onto each other to make a free-standing bilayer film. The parallel slurry casting approach eliminates cross-compatibility requirements of the solvents used for slurry preparation. The resulting bilayer films after densification were pin-hole free without intermixing between the two phases. The ionic conductivity of the bilayer SE film was ~70% of the bilayer SE pellet (1 mm thickness in total) made with a conventional powder pressing method. However, because the thickness of bilayer SE film (60 μm) was much smaller than the bilayer SE pellet (1 mm), the bilayer SE film had ~10x lower area-specific resistance (ASR) compared to the bilayer SE pellet. Because of the lower total cell resistance, the cell made with the bilayer SE film had a better rate capability compared to the reference cell in pellet geometry.The strategy developed in this work could be integrated into current manufacturing infrastructure of battery fabrication as it is based on slurry casting, which is already a well-established fabrication method for lithium-ion batteries. Moreover, it could be used to fabricate multi-layered solid-state architectures in general, which are challenging to manufacture due to solvent compatibility issues during slurry casting. The study will assist the progress of solid-state battery manufacturing by providing a scalable manufacture method to prepare thin free-standing bilayer SEs.

This review article delves into the growing field of solid-state batteries as a compelling alternative to conventional lithium-ion batteries. The article surveys ongoing research efforts at renowned Swiss institutions such as ETH Zurich, Empa, Paul Scherrer Institute, and Berner Fachhochschule covering various aspects, from a fundamental understanding of battery interfaces to practical issues of solid-state battery fabrication, their design, and production. The article then outlines the prospects of solid-state batteries, emphasizing the imperative practical challenges that remain to be overcome and highlighting Swiss research groups’ efforts and research directions in this field.

Flexible solid-state lithium metal batteries (SSLMBs) are highly desirable for future wearable electronics because of their high energy density and safety. However, flexible SSLMBs face serious challenges not only in regulating the Li plating/stripping behaviors but also in enabling the mechanical flexibility of the cell. Both challenges are largely associated with the interfacial gaps between the solid electrolytes and the electrodes. Here, a UV-permeable and flexible composited Li metal anode (UVp-Li), which possesses a unique light-penetrating interwoven structure similar to textiles is reported. UVp-Li allows one-step bonding of the cathode, anode, and solid electrolyte via an in situ UV-initiated polymerization method to achieve the gapless SSLMBs. The gapless structure not only effectively stabilizes the plating/stripping of Li metal during cycling, but also ensures the integrity of the cell during mechanical bending. UVp-Li symmetric cell presents a stable cycling over 1000h at 0.5mA cm-2. LiFePO4||UVp-Li full cells (areal capacity ranging from 0.5 to 3 mAh cm-2) show outstanding capacity retention of over 84% after 500 charge/discharge cycles at room temperature. Large pouch cells using high-loading cathodes maintain stable electrochemical performance during 1000 times of dynamic bending.

Abstract In this work, we explored the recovering possibilities of nickel‐based products from the cathode materials of spent nickel‐metal hydride (NiMH) batteries collected from car repair centers in Mongolia. Specifically, nickel‐based by‐products such as metallic nickel, Ni microparticles, nickel oxide, nickel chloride, and betta‐phase (β) nickel hydroxide powders are successfully produced. X‐ray diffraction patterns suggested that all samples show high crystallinity and phase purity. Ni microparticles were recovered using a chemical reduction method from a leachate solution prepared by dissolving the cathode of the spent NiMH battery in hydrochloric acid. Notably, β‐Ni(OH)₂ displayed two redox peaks in KOH electrolyte solution, suggesting that it has excellent electrochemical potential and can be reused for the fabrication of new NiMH batteries. To validate the electrochemical performances, we examined the catalytic activity of nickel microparticles as a catalyst for the degradation of Congo red (CR) dye and oxygen evolution reaction (OER). The reduction reaction rate of CR dye in the presence of a nickel catalyst was 2.17×10−3 s−1, significantly higher than the control experiment without a nickel catalyst. These results provide possible solutions for developing sustainable battery systems by recovering different nickel‐based products from spent NiMH batteries.

Abstract Fiber batteries are essential for the realization of high‐performance wearable and textile electronics with the desirable features of conventional textiles, including breathability, stretchability, and washability. However, the development of fiber batteries is limited by scalability and performance since most reported fabrication techniques are not compatible with standard battery manufacturing. This work presents a novel method for the scalable fabrication of fiber batteries with a stacked design analogous to that of conventional pouch cells using layer lamination and laser machining. To accomplish this, several poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) separators are developed, enabling lamination between conventional battery electrodes using a heated rolling press. The laminated strips are subsequently laser cut to form fibers with widths as narrow as 650–700 µm. These prototypes are successfully cycled in pouch cells and capillary tubes, delivering very high linear energies up to 0.61 mWh cm−1. Custom equipment is designed to demonstrate scalable fiber battery fabrication processing in a roll‐to‐roll fashion. This work marks a paradigm shift in fiber battery research by demonstrating substantial benefits over all previous approaches including optimal active material utilization, low inactive material content, scalability, and compatibility with equipment already used widely in the battery industry.

Natural low corrosive phytic acid electrolytes enable green, ultrafast, stable and high-voltage aqueous proton battery

Theoretical study of adsorption of sodium, lithium, magnesium and calcium chloride and sulfate salts by pure and Sc-doped B12N12 nanocages and pure boron nitride nanosheet

Two-electron conversion nitroxide radicals-based electrode synergistically enhancing charge storage in water-in-salt electrolyte

The effects of fluorine doping on the structure, interface and electrochemical properties of lithium titanate

This study aims to investigate the impact of varying the mass ratio of Ni to Graphene Nano Sheets (GNS) and how incorporating GNS affects the performance of a primary battery prototype (Ni/GNS//electrolyte//GNS). The primary battery prototype was developed using both impregnation and alloy methods. Different mass ratios of Ni/GNS to electrolyte to GNS were tested, including ratios of 1:2:1 (A), 2:2:1 (B), 1:2:2 (C), 2:1:2 (D), and 1:1:2 (E). The characterization of GNS, Ni/GNS, and the primary battery prototype involved using X-Ray Diffraction (XRD) and Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX) instruments. A multimeter was employed to measure electrical conductivity, energy density, and power density. A potentiostat/galvanostat was used to measure cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). XRD analysis showed a broad and weak peak at 2θ= 24.32° for GNS, confirming its successful synthesis. Additionally, a peak at 2θ = 43.5° indicated effective deposition of Ni on the GNS surface in Ni/GNS. The SEM-EDX results supported the XRD findings, showing regularly spaced pores and a thin surface layer in GNS. Notably, white spots on the graphene surface in Ni/GNS indicated successful Ni deposition. In terms of electrical conductivity, the highest value was observed in the primary battery prototype for sample D (2:1:2), which measured 1.11 S/cm2. These results were also supported by measurements of energy density and power density in sample D, which achieved the highest values among all samples, with 144,788 Wh/kg and 252,500 W/kg, respectively. Moreover, the CV and EIS measurements remained stable at 0.30 kΩ and 0.88 kΩ, suggesting that GNS could potentially conduct electrons owing to its electrical conductivity.

The phosphate lithium-ion conductor Li1.5Al0.5Ti1.5(PO4)3 (LATP) is an economically attractive solid electrolyte for the fabrication of safe and robust solid-state batteries, but high sintering temperatures pose a material engineering challenge for the fabrication of cell components. In particular, the high surface roughness of composite cathodes resulting from enhanced crystal growth is detrimental to their integration into cells with practical energy density. In this work, we demonstrate that efficient free-standing ceramic cathodes of LATP and LiFePO4 (LFP) can be produced by using a scalable tape casting process. This is achieved by adding 5 wt % of Li2WO4 (LWO) to the casting slurry and optimizing the fabrication process. LWO lowers the sintering temperature without affecting the phase composition of the materials, resulting in mechanically stable, electronically conductive, and free-standing cathodes with a smooth, homogeneous surface. The optimized cathode microstructure enables the deposition of a thin polymer separator attached to the Li metal anode to produce a cell with good volumetric and gravimetric energy densities of 289 Wh dm-3 and 180 Wh kg-1, respectively, on the cell level and Coulombic efficiency above 99% after 30 cycles at 30 °C.

Multi-stage stabilization and high-strength nano-porous Si@C for simple fabrication of lithium-ion batteries