Battery Assembly Research Articles

Cathode-Electrolyte Interphase in Lithium Batteries Revealed by Cryogenic Electron Microscopy

Summary Cathode electrolyte interphase (CEI), the intimate coating layer formed on the positive electrode, has been thought to be critical. However, many aspects of CEI remain unclear. This originates from the lack of effective tools to characterize structural and chemical properties of these sensitive interphases at nanoscale. Here, we develop a protocol to preserve the native state and directly visualize the interface on the positive electrode using cryogenic electron microscopy. We find that under normal operation conditions, there does not exist an intimate coating layer at the single-particle level in carbonate-based electrolyte. However, upon brief external electrical shorting, a solid-electrolyte interphase, which usually forms on anodes, could form on cathodes and be electrochemically converted into a stable, conformal CEI in situ. The conformal CEI helps improve Coulombic efficiency and overall capacity retention of the battery. This generates a different perspective of CEI in commercial carbonate-based electrolytes than previously understood.

Laser-Assisted Filler-Based Joining for Battery Assembly in Aviation

Laser-Assisted Filler-Based Joining for Battery Assembly in Aviation

The electrochemical properties and reaction mechanism of orthorhombic Mn2SiO4 cathode for aqueous rechargeable zinc ion batteries

Manganese-based cathodes for aqueous rechargeable zinc ion batteries (ZIBS) are attracting extensive attention owing to high energy density, high safety of mild aqueous electrolyte, environmental friendly, facile battery assembly and low cost of sources materials. Here, a new manganese-based battery system for aqueous ZIBs by employed orthorhombic manganese silicate (Mn2SiO4) as cathode, Zn metal as anode, mild aqueous ZnSO4 + MnSO4 as electrolyte is reported for the first time. The Zn/Mn2SiO4 battery shows good Zn storage performance and can deliver reversible capacity of 154 mA h g−1 in the first cycle. Notably, the battery undergoes capacity deterioration in initial cycles, but exhibits superior cyclic stability after several cycles. A comprehensive study reveals the electrochemical reaction mechanism of this battery system is the irreversible phase transition from Mn2SiO4 to amorphous todorokite MnO2, amorphous SiO2 and crystalline phase occurs during the first charge, and followed by reversible conversion reaction between amorphous phase (todorokite MnO2 and SiO2) and crystalline phase (MnOOH, ZnxMnO2 and Zn2SiO4) in the subsequent cycles. Although the practical capacity and reaction mechanism needs to be clearly evaluated, this work could provide new insights into exploiting other advanced cathodes for aqueous rechargeable ZIBS.

Li-ion Battery Research in Hierarchical Green-Energy Materials Research Center

Hierarchical Green-Energy Research Center aims to promote materials innovation of Li-ion battery (LIB) for electric scooter and MWh class energy storage. Our team has mainly developed strategies for material optimization and research methodology for the improvement of electric power and cyclic stability of LIB. Metal oxides are abundant in defect structures that determine electric conductance and electrochemical activity. The first principle calculation of lithium titanate (LTO) was applied to access the electronic structure of pristine LTO and aliovalent ion-doping LTO. The other oxides were chosen as nanostructured anode materials anchored on reduced graphene oxide. We found that their cyclic ability is significantly improved due to the structurally synergetic effect between oxide nanocrystallite and substrate; Si is regarded as one of the most popular anode materials for 3rd generation LIB, but its cycle life is still limited by an overgrowth of secondary electrolyte interface (SEI). Glucose-derived Si-O-C ligand in modified SEI possessed a high affinity to Li-chelation, thus alleviating volume expansion and structural instability. Electrolyte design is considered the current technical bottleneck for the implementation of high voltage LIB. An ionic liquid hybrid electrolyte has been demonstrated excellent oxidation potential of the carbonate solvent, resistance to Al corrosion, and potential of ~5.0 V (vs. Li+/Li) even at an operating temperature of 55oC. Another highlight in the center is gel polymer electrolyte (GPE) that enables enhancement of lithium-ion transference number of 0.57 by the existence of the imidazolium group. The newly designed GPE guaranteed effective Li+ pathways in electrolyte bulk and at electrode/electrolyte interfaces, a high potential of 5.4 V, and simplicity of electrolyte synthesis and all-solid-state battery assembly for industrial-scale production processes.

Recent Advances in High-Performance Microbatteries: Construction, Application, and Perspective.

High-performance miniaturized energy storage devices have developed rapidly in recent years. Different from conventional energy storage devices, microbatteries assume the main responsibility for micropower supply, functionalization, and characterization platforms. Evolving from the essential goals for battery design of high power density, high energy density, and long lifetime, further practical demands for microbatteries (MBs) have been raised for the microfabrication technique and device design. Numerous studies have generally focused on specific aspects of the microelectrode structures or certain microfabrication techniques, while the connection from techniques to functional applications is rarely involved. This Review generally fills such blanks from an application-oriented perspective. First, some basic micromachining techniques with different compatible features are summarized. Afterward, device designs including diversified battery reaction types, configuration, and assembly are highlighted, as well as microbatteries serving powering resources or further complicated functional systems. Finally, through providing the overall design concept based on requirements in application, this Review offers innovative insights for further development of microbatteries.

On electrolyte wetting through lithium-ion battery separators

The wettability by electrolyte is a critical characteristic of lithium-ion battery separators since electrolyte absorption is essential for ionic transport. Most importantly, fast absorption of electrolyte facilitates the electrolyte filling and wetting processes during the battery assembly. However, theoretical or experimental investigation of separator wettability has rarely been reported, and thus very little quantitative data can be found in the existing literature. In this study, innovative experimental techniques and associated analytical models have been developed to fully characterize the electrolyte wetting behavior through battery separators. Both in-plane and through-plane imbibition processes are investigated. The results show that, electrolyte needs significantly longer time to wet separators than it does for commercial electrodes. The wetting rate depends significantly on the pore size, porosity, and micro-structure of the separators. Electrolyte in-plane wetting is only observed in the separators manufactured by the wet process. Increasing separator porosity and pore size is shown to be substantially increasing through-plane wetting rate. In addition, ceramic coating is shown to increase in-plane wetting but retard through-plane wetting.

Considerations of potential runaway motion and physical interaction for speed and separation monitoring

In the field of human-robot collaboration (HRC), the speed and separation monitoring (SSM) collaboration have attracted much attention owing to its non-contact safety strategy. 3D sensing applications are currently of interest for industrial automation technology and are considered to be a promising method for maximizing the efficiency of SSM. However, little attention has been given to the runaway space of the robot or the potential contact due to the foreseeable misuse of the operator. In this study, experiments are conducted using a radar system as an example of a 3D safety-related sensor, and battery assembly scenarios are carried out for the comparison. In the experiment, two different orientations of the robot are tested, considering the potential runaway motion of the robot. Also, the maximum permissible speed of the robot is calculated by geometrical transfer energy, which is based on effective mass and the velocity of the manipulator and human injury criteria. From the experimental results, it is evident that it is better to avoid placing the vertical articulated robot in front of the operator from the perspective of minimizing the effect of runaway motion into the safety distance. Finally, the proposed framework of speed limitation is thought to be an effective method to link SSM and power and force limiting safety function.

Flexible All-Solid-State Li-Ion Battery Manufacturable in Ambient Atmosphere.

The rational design and exploration of safe, robust, and inexpensive energy storage systems with high flexibility are greatly desired for integrated wearable electronic devices. Herein, a flexible all-solid-state battery possessing competitive electrochemical performance and mechanical stability has been realized by easy manufacture processes using carbon nanotube enhanced phosphate electrodes of LiTi2(PO4)3 and Li3V2(PO4)3 and a highly conductive solid polymer electrolyte made of polyphosphazene/PVDF-HFP/LiBOB [PVDF-HFP, poly(vinylidene fluoride-co-hexafluoropropylene)]. The components were chosen based on their low toxicity, systematic manufacturability, and (electro-)chemical matching in order to ensure ambient atmosphere battery assembly and to reach high flexibility, good safety, effective interfacial contacts, and high chemical and mechanical stability for the battery while in operation. The high energy density of the electrodes was enabled by a novel design of the self-standing anode and cathode in a way that a large amount of active particles are embedded in the carbon nanotube (CNT) bunches and on the surface of CNT fabric, without binder additive, additional carbon, or a large metallic current collector. The electrodes showed outstanding performance individually in half-cells with liquid and polymer electrolyte, respectively. The prepared flexible all-solid-state battery exhibited good rate capability, and more than half of its theoretical capacity can be delivered even at 1C at 30 °C. Moreover, the capacity retentions are higher than 75% after 200 cycles at different current rates, and the battery showed smaller capacity fading after cycling at 50 °C. Furthermore, the promising practical possibilities of the battery concept and fabrication method were demonstrated by a prototype laminated flexible cell.

Multi-agent deep reinforcement learning based demand response for discrete manufacturing systems energy management

With advances in smart grid technologies, demand response has played a major role in improving the reliability of grids and reduce the cost for customers. Implementing the demand response scheme for industry is more necessary than for other sectors, because its energy consumption is often considered the largest. This paper proposes a multi-agent deep reinforcement learning based demand response scheme for energy management of discrete manufacturing systems. In this regard, the industrial manufacturing system is initially formulated as a partially-observable Markov game; then, a multi-agent deep deterministic policy gradient algorithm is adopted to obtain the optimal schedule for different machines. A typical lithium-ion battery assembly manufacturing system is used to demonstrate the effectiveness of the proposed scheme. Simulation results show that the presented demand response algorithm can minimize electricity costs and maintain production tasks, as compared to a benchmark without demand response. Moreover, the performance of the multi-agent deep reinforcement learning approach against a mathematical model method is investigated.

A Novel Sulfur‐Based Terpolymer Cathode Material for Lithium–Sulfur Battery

Herein, the preparation and characterization of a novel sulfur‐based terpolymer via inverse vulcanization and dynamic covalent polymerizations using the raw materials of elemental sulfur, styrene, and peanut oil are reported. The sulfur content of this terpolymer is about 72 wt%. As it is viscous but flowable at room temperature, it can be mixed with conductive graphene without binders. Poly(sulfur–styrene–peanut oil) (poly(S–Sty–P)) terpolymer is further successfully utilized as the active cathode material in Li–S batteries. The initial specific capacity of this kind of battery reaches 1008 mAh g−1. After 100 cycles, the specific capacity keeps at 611 mAh g−1 with the capacity retention rate above 60% and coulombic efficiency close to 100%. Compared with the traditional sulfur cathode material, this terpolymer cathode material exhibits higher capacity, better cycle performance, and superior high‐rate performance. In addition, it can be directly coated on the aluminum foil collector without additional binders, which reduces the internal resistance effect from additional binders and simplifies the battery assembly process.

Two-pronged approach to regulate Li etching for a stable anode

Different carbon networks have been routinely used to modify Li anodes, which results in uniform nucleation on carbon materials. However, less attention is paid to the etching behavior of the Li metal under a modification layer. In this work, a failure analysis of a Li anode modified by an N-doped carbon nanofiber (CNF) demonstrates that pitting of the Li substrate is related to the final polarization of anode after relatively long cycling. A new approach is aimed at further improving the stability of a Li anode for long-period plating/stripping. The “two-pronged approach” combines a superficial SnOx decoration on the CNF and a plate-shell of Sn on the Li substrate that improves the electrochemical stability of Li. The superficial SnOx particles on the CNF induces the uniform deposition of Li on the CNF surface via a superficial alloying effect. The in situ formation of Li13Sn5 induces planar etching/growth of the Li substrate that improves the areal current density by two orders of magnitude. The “two-pronged approach” modified cells shows reduced polarization under a current density of 3 mA/cm2 and 5 mA/cm2 for 900 and 600 cycles, respectively. The “two-pronged approach” is also demonstrated by a full battery assembly with LiFePO4.

Improved battery safety via in-situ dip-coated composite gel polymer electrolytes

A new type of PVC-CPVC-MBS-B44 composite gel polymer electrolyte (GPE), based on LiTFSI and incorporated with nano-silica, is designed. The adhesion of the electrolyte membranes is improved by introducing B44, with its excellent adhesion ability, into the GPEs. The GPE membrane is coated on the anodes by an in-situ dip-coating process for battery assembly, reducing the interfacial resistance of the battery. The PVC-CPVC-MBS-B44 composite GPE exhibits superior electrochemical performance. The electrochemical window is over 4.9 V (vs. Li/Li+), the ion conductivity is 0.96 × 10- 3 S cm−1 at an ambient temperature, and the lithium ion transference number is 0.61. The LiCoO2/PVC-CPVC-MBS-B44 composite GPE/graphite cells exhibit maximum discharge capacities of approximately 137.98, 136.5, and 129.4 mAh g−1 at 0.2C, 0.5C, and 1C discharge rates, respectively. The cells with GPE can maintain a high discharge capacity of 116 mAh g−1 and a capacity retention exceeding 82.9% after 200 cycles at 0.5C. Heavy impact, nail penetration, crush test, short-circuit test, drop test and heating test are carried out on 1-Ah GPE pouch cells, and the battery does not ignite nor smoke. A battery prepared using the proposed approach can deliver outstanding safety, high rate capabilities, and superior cycle stability, making it a potential candidate for various applications.

High-power, non-enzymatic glucose biofuel cell based on a nano/micro hybrid-structured Au anode

In this study, a high-power, non-enzymatic glucose biofuel cell (GBFC) based on a nano/micro hybrid-structured Au anode is proposed. A uniformly distributed micro-hemispheric array of polycarbonate is fabricated for this novel electrode by hot embossing using a Ni mold. The nano/micro hybrid-structured Au anode is then fabricated by depositing an Au nanoparticle monolayer on the micro-hemispheric array using 1,6-hexanedithiol as a two-sided anchor. The cathode is composed of a graphene film-coated glassy carbon electrode. Nafion, a proton exchange membrane, is used to separate the anode and cathode and complete the battery assembly. Experimental results demonstrate that the proposed non-enzymatic GBFC has a high-power density of 10.7 mWcm−2, a high current density of 29.5 mAcm−2, an open-circuit voltage of 8.2 V, and a shorted-circuit current of 34 mA at room temperature. The energy conversion efficiency of the electrode is calculated to be 52.47%. In addition, the proposed GBFC possesses advantages such as ease of production on a large scale, low manufacturing cost, high repeatability, and long-term preservation. Therefore, it is highly feasible for commercialization and use in practical applications.

Mechanical System Design and Simulation Research of a Demonstration Assembly Line

Most assembly lines use a bottom-up mechanical system design approach. In view of the problems of poor system interchangeability and low product versatility, a battery assembly line was designed based on the modular design method. The linear modules, cylinders and linear guides were used as the basic elements to build the production line modules. Different assembly requirements have improved the performance of the entire production line. The discrete-event system simulation method is used to simulate the quasi-running process of the production line, analyze the bottleneck of the production line, and improve the production efficiency of each module of the production line by changing the optimization method of the loading link and the production sequencing.

Environmental and economical assessment for a sustainable Zn/air battery

Metal/Air batteries are being developed and soon could become competitive with other battery technologies already in the market, such as Li-ion battery. The main problem to be addressed is the cyclability, although some progress has been recently achieved. A Life Cycle Assessment (LCA) of the manufacturing process of a Zn/Air battery is presented in this article, including raw extraction and process of materials and battery assembly at laboratory scale (cradle to gate approach). The results indicate that Zn/Air battery can be fabricated with low environmental impacts in most categories and only four deserve attention (still being low impacts), such as Human Toxicity (cancer and non-cancer), Freshwater Ecotoxicity and Resource Depletion (the later one depending mainly on Zn use, which is not a critical material, but has a strong impact on this category). Cathode fabrication arises as the subassembly with higher impacts, followed by membrane, then anode and finally electrolyte. An economic cost calculation indicates that if cyclability of Zn/Air batteries is achieved, they can become competitive with other technologies already in the market.

Effects of Ultrafine Bismuth Powder on the Properties of Zinc Electrodes in Zinc-Air Batteries

Ultrafine spherical zinc powder prepared by direct-current arc plasma evaporation increased the capacity and life of zinc-air batteries. To decelerate the corrosion of the ultrafine zinc powder and improve the charge–discharge performance of the zinc-air batteries, we added different amounts of ultrafine bismuth powder to a zinc electrode. The hydrogen evolution rate of the Zn-Bi electrode and the properties of zinc-air batteries were investigated by hydrogen evolution experiments and electrochemical performance tests. The corrosion inhibition mechanism of the newly added bismuth powder on the zinc electrode was studied via x-ray diffraction, scanning electron microscopy and x-ray photoelectron spectroscopy. The results show that when the amount of the ultrafine bismuth powder was 1.5 wt.% of the zinc powder, the anticorrosion efficiency of the Zn-Bi electrode was the highest, reaching 53.8%. After the battery assembly, the Zn-Bi electrode reached a capacity retention rate of 84.6% and had a 21.7% higher specific capacity than that of a blank zinc electrode (419 mA h g−1 versus 344.3 mA h g−1) after 60 cycles. The ultrafine bismuth powder improved the nucleation efficiency, reduced the corrosion current, increased the polarization resistance threefold, and inhibited the formation of dendrites and corrosion, thereby increasing the battery specific capacity and cycle efficiency.

Mechanism, strategies, and characterizations of Li plating in solid state batteries

Commercial lithium-ion batteries have inherent safety problems due to the usage of non-aqueous electrolyte as the electrolytes. The development of solid state lithium metal batteries is expected to solve these problems while achieving higher energy density. However, the problem of lithium plating still exists. This article reviews the deposition behavior of lithium metal anodes in solid-state batteries, and provides suggestions for high-energy-density and high-safety solid-state lithium batteries. This paper systematically summarizes the mechanism of Li deposition in polymers and inorganic solid state electrolytes, and discusses the strategies of controlling lithium deposition and preventing lithium dendrites and the characterization of Li metal anodes. In solid-state batteries, poor solid-solid contact between the electrolyte and the anode, defects, grain boundaries, cracks, pores, enhanced electric and ionic fields near the tip, and high electronic conductivity of the solid state electrolyte can all lead to lithium deposition, which may evolve into lithium dendrites. There are several strategies to control lithium deposition: 1). Use functional materials and structure design to induce uniform deposition of lithium, such as improving the solid state electrolyte/anode interfacial contact, using lithiophilic coatings or sites, and designing three-dimensional structure electrodes and solid state electrolytes. 2). Suppress the generation of lithium dendrites, such as limiting the free movement of anions in solid state electrolytes (especially polymer solid electrolytes), to reduce local space charge which induces lithium dendrites. In addition, optimizing the solid electrolyte synthesis process to reduce lithium dendrites caused by defects is also an important method. 3). Strategies for dendrites already formed are essential for safety concern. The dendritic deposition is one of the intrinsic properties of lithium. Thus, there is no guarantee that there will be no lithium dendrites, especially at high current density. Once lithium dendrites are formed, countermeasures are required. For example, improving the mechanical strength of solid state electrolytes, and using self-healing materials, structures, and cycling conditions are proposed to avoid safety hazards caused by lithium dendrites piercing. This article focuses on the control of lithium deposition. Suppressing lithium dendrites only solves a little problem of the application of lithium metal anodes. In the future, in order to use lithium metal as a negative electrode in practical all-solid-state batteries, many challenges need to be overcome, such as irreversible side reactions between lithium and other materials, safety and volume change of composite lithium anodes. In addition, in order to allow the laboratory's research results to be quickly transformed into applications, it is also necessary to establish battery design, assembly, and test standards that are in agreement with practical requirements. In short, all-solid-state lithium batteries still have a long way to go, but they have great potential for safe, high-performance, and low-cost energy storage systems in the future.

Contributions of lean six sigma to sustainable manufacturing requirements: an Industry 4.0 perspective

Abstract Industry 4.0 is reshaping modern manufacturing with increased data availability and accessibility. Therefore, further support of the system and product lifecycles is provided. On the other hand, sustainable manufacturing gains more attention due to the environmental concerns and resource consumption. The green impact of lean six sigma has been approached in literature. However, the changes to a manufacturing system’s nature provide new insights to employ lean six sigma quality tools for further sustainability. This paper proposes a framework of using six sigma to achieve the sustainable manufacturing requirements from the perspective of Industry 4.0 and its enablers. The influence of information and communication technologies (ICTs) on the relationship between sustainable manufacturing 6R and lean six sigma DMAIC is studied. A case study of cylindrical cell battery assembly line is used to investigate the effectiveness of the proposed approach. The framework can be adjusted to suit different types of manufacturing processes and systems.

Automated assembly of Li-ion vehicle batteries: A feasibility study

Electric Vehicles (EVs) with rechargeable Lithium-Ion batteries (Li-ion) are at the forefront of the global trend for lower-emission transportation and decarbonisation. Capable suppliers of Li-Ion battery assembly systems are essential for enabling automotive OEMs to scale up their Li-ion EV production to expected volumes. This paper details a feasibility study for Li-Ion battery assembly, developed for a traditional automotive supplier of niche production systems in order to enable them to enter the emerging lower carbon OEM supply chains. Through simulation modelling, the essential components of a reconfigurable and scalable EV Li-ion batteries assembly system with provision for disassembly are explored and a generic framework is proposed.

Tests of BMS Battery Management System with active and passive system of balancing the battery capacity

The tests of two BMS Battery management systems, equipped with active and passive systems of balancing the battery capacity, realized within the framework of the HYDKOM 75 project, are discussed in the article. These test were performed on the lithium-ferric-phosphate(LiFePO4) battery assembly for the mining mobile machine of BH 3000 B HYDKOM 75 type. The object of tests included two Battery Management Systems (BMS). The first one was a commercially available system most often used in the automobile industry, however the second one was the author’s BMS-Battery Management System developed at the KOMAG Institute of Mining Technology within a realization of the HYDKOM 75 project. The tests were conducted both during a battery charging process as well as during discharging the LiFePO4 battery for different values of the load current.