Battery Concept Research Articles

An optical flow battery enabled by trap-engineered nanophosphors

Flow batteries represent a promising technology for storing electrical energy in circulating electrolyte solutions that contain redox-active chemicals. Inspired by the redox flow battery, in this paper we describe the concept and implementation of an optical flow battery, which stores photon energy in circulating nanophosphor colloids. Similar to the redox flow battery, the optical flow battery enables the conversion between photon energy and chemical energy in a rechargeable manner, facilitating distributed energy storage by decoupling energy and power. We characterized basic cell attributes and performance metrics of this prototype optical flow battery in the context of common assessment methods for conventional redox flow batteries. We envision that this optical flow battery may provide a useful tool for solar energy storage, light delivery in live animals, and light-based therapy, diagnosis, and surgery in medicine.Graphical

Storing electricity in the low-rank coal: The heat-upgrading carnot battery concept and a comprehensive thermodynamic analysis

Promoting the energy/exergy performance of Carnot batteries is beneficial for future applications. This work proposed a Carnot battery concept deeply integrated with the low-rank coal (LRC) power plant (LCPP) for (1) enhancing the energy/exergy performance and (2) reducing LCPP's carbon emission and the minimum technical output (to adopt excess renewable power). The enhancement is attributed to the heat-upgrading effect of LRC pre-drying process and the energy complementarity between the subunits. A thermodynamic model based on the typical LCPP and Carnot battery cases is established to assess and analyze the proposed system. As the results show: (1) Daily average round-trip/exergy efficiencies reach 70.92 % and 54.28 %, and 3.36 % of carbon emission (126.52 ton/day) is reduced in 24 h, significantly higher than the conventional HP-ORC Carnot battery integrated with LCPP. (2) The performance of the proposed Carnot battery cannot be directly predicted from the subunits' performance due to the discharge during the charging periods; however, as long as the integrated charging capacity is not too small, the energy/exergy performance can maintain an elevated level. (3) For a generalized HP-ORC Carnot battery, low exergy input of discharging cycle limits the performance improvement; however, in the proposed system, the energy-upgrading effect compensates for this shortcoming.

Perspectives on Photocatalytic Paper‐Based Batteries Fueled by Alcohol

AbstractAmid growing energy demands, innovative solutions are essential to power a variety of devices. Paper‐based microfluidic fuel cells (PμFCs), powered by eco‐friendly alcohols derived from biomass, present a promising option. While lightweight and disposable, they mainly rely on costly noble‐metal catalysts for high efficiency. In this context, the concept of photo paper batteries (pPBs), utilizing affordable sunlight‐activated semiconductors to drive alcohol oxidation on paper, opens the possibility to disposable and affordable energy solutions. Our review highlights recent progress in PμFCs fueled by alcohols like methanol, ethanol, ethylene glycol, and glycerol. We explore semiconductor advancements driving anodic reactions and envision the potential of pPBs. To achieve practical pPBs, refining semiconductors, electrode design, and microfluidic engineering are pivotal. This short review highlights the transformative potential of pPBs and beckons researchers to partake in shaping this new field.

ANALYSIS OF BIDIRECTIONAL DC-DC POWER CONVERTERS FOR SCREENING SYSTEMS OF RETIRED BATTERIES

With the rapid expansion of energy storage technologies, the concept of the second-life battery has become a central element in sustainability and energy efficiency efforts. This innovative approach refers to the further use of batteries, which have reached the end of life, integrating them into applications with lower energy requirements than those in the automotive industry. The batteries must first be evaluated using a screening system that contains a power converter to apply different test profiles and a measurement and control circuit. This article outlines key performance considerations of bidirectional DC-DC power converter topologies and compares them using multi-criteria analysis to determine which design is more suitable for screening systems. The chosen power converters are further studied in the LTspice program for a detailed comparison based on the obtained results.

Next-Generation Batteries through Advanced 3D Electrode and Material Concepts

With the rise of renewable energy sources, energy storage solutions become increasingly important as they represent a key feature for secure and constant power supply. In this regard, battery systems play a crucial role in accelerating the transition towards sustainable and green energy sources. To meet the rising global demand, further advancement of the battery technology is imperative. One optimization pathway is to use battery materials that are more sustainable while also yielding improved electrochemical performance, contributing to both environmental and functional advancements. However, innovation must go beyond the material level, and new electrode design approaches for an efficient combination of high power and high energy systems are necessary.In this context, the three-dimensional (3D) battery concept with its increased exposed electrode surface, shows a great promise for enhanced electrochemical performance compared to the conventional flat designs of state-of-the-art electrodes. Targeting at the bottleneck of high power/high energy density systems, the incorporation of micro-structured channels within the electrodes improves lithium-ion diffusion pathways and minimize strain from volume expansion during electrochemical cycling.Our focus is the investigation of 3D electrode architectures generated by laser-processing techniques such as ultrafast laser ablation and laser-assisted printing. Working with ultrafast lasers offers the possibility to process materials while reducing thermal impact and allows the creation of well-designed and controllable electrode surface topographies. The adoption of this concept has already shown great impact in enhancing the high-rate capability and lifetime of conventional electrodes in lithium-ion batteries.[1-3] Expanding the scope, this work explores the applicability of laser-generated 3D electrode architectures to next-generation battery active materials such as high-voltage lithium nickel manganese oxide (LNMO) composites. On anode side, silicon/graphite and amorphous carbon is extensively investigated for lithium-ion batteries and sodium-ion batteries, respectively. To understand the impact of the manufacturing process, electrochemical evaluations are complemented by findings from laser-induced breakdown spectroscopy, SEM-EDX, Raman measurements, and Auger electron spectroscopy.In conclusion, this contribution highlights the promising advancements achieved by applying laser-generated 3D electrode architectures to next-generation battery materials and aims to provide valuable insights into this exciting frontier of battery research.[1] W. Pfleging, Nanophotonics 7 (2018) 549–573.[2] W. Pfleging, Int. J. Extrem. Manuf. 3 (2021) 012002.[3] M. Zaeh, Appl. Energy 303 (2021), 117693.

(Invited) Battery Safety and Self-Quenching Battery Pack Concept: D3 (Dissipate, Direct, and Douse Heat and Fire)

Battery pack safety following an individual cell runaway is an important aspect to address as we pack more energy into a small volume and mass. Thermal runaway incidents are extremely rare but can be catastrophic. The runaway can be triggered by local overcharge, thermal or mechanical abuse.In this talk, we will first go into the details of thermal runaway initiation and propagation. Second, solution to quench the thermal runaway from propagating within the cell through a novel and passive detection of incipient thermal runaway temperature via thermoplastics will be introduced; and that is followed by discussion on the coolant release trigger to quench the runaway. In addition, this solution prevents propagation from cell-to-cell and reduce the chance for secondary combustion. This solution also leverages the fast thermal conductivity that is offered by the Cu and Al current collectors within the cell. The role of current collectors in relaying the information from the source of thermal runaway to the surface of the new format cell will be discussed.The solution proposed here is chemistry agnostic and can be adapted to applications such as in transportation of cells and packs, grid energy storage, and mobility. The talk concludes by describing the next steps and value chain partnerships to make this safer solution a reality.Below is an image that shows the self-quenching battery concept. Figure 1

Quantum-Chemistry Enabled AI for Materials Discovery for Energy Storage

A priori and reliable simulations can enable timely and cost-efficient design and discovery of materials for energy. Therefore, ‘Let’s Start from Computing’ is an optimal approach to initialize modern day R&D processes. In energy storage, beyond lithium-ion (BLI) research has the potential to revolutionize consumer electronics including portable and stationary power, transportation, and grid energy storage sectors. Multi-valent (Mg, Ca, Zn) energy storage or economically viable monovalent (Na, K) batteries, high-density metal-air, metal-sulfur batteries, or grid-storage systems are considered in the beyond lithium-ion research and development. All these R&D efforts require significant fundamental knowledge via a priori computations for materials discovery, property prediction, and optimization. Atomistic modeling when coupled with reliable Artificial Intelligence (AI) approaches can provide accurate insights to accelerate discovery of optimalelectrolytes, electrodes, and membranes for BLI systems to reduce the cost. Thus, coupled with AI and multi-scale simulations techniques, atomistic modeling can address prediction of molecular level properties of materials (redox potentials, solvation, spectroscopic, and reactivity) to down-select optimal materials or material combinations. In this presentation, I will describe some of our recent efforts in active learning coupled with large scale first principles simulations to down select/optimize desired molecules for flow battery technology. This concept can be utilized for design of experiments using autonomous experimentation. Additionally, I will describe some of our quantum chemistry-informed molecular property predictions redoxmers and liquid organic hydrogen carriers. In addition to molecules, I will present. A data driven approach to study longer time scale diffusion of ions for multivalent battery concepts. Figure 1

A Small Electrolyte Drop Enables a Disruptive Semisolid High‐Energy Sulfur Battery Cell Design via an Argyrodite‐Based Sulfur Cathode in Combination with a Metallic Lithium Anode

AbstractLithium–sulfur batteries with liquid electrolytes are discussed as the most promising post‐lithium‐ion‐battery technology in literature due to their high theoretical specific energy and first prototype cells delivering >470 Wh kg−1. Although several electrolyte and material concepts are developed that partially solve the issue of the so‐called shuttle mechanism, the most promising concept to genuinely confine sulfur species in the cathode is all‐solid‐state argyrodite–sulfur cathodes leading to almost theoretical active material utilization by maintaining reasonable sulfur loadings and electrolyte to sulfur ratios. However, this battery concept has so far not achieved reversible cycling against metallic lithium anodes as it requires high pressures for manufacturing, and ductile lithium metal creeps along the grain boundaries of the solid electrolyte particles leading to short cuts of the cells. Recent findings show that metallic lithium, however, can be stably cycled with dimethoxyethane/lithium‐bis(fluorosulfonyl)imide (DME/LiFSI)‐based electrolytes. Herein, for the first time, a semisolid concept is presented combining the benefits of an argyrodite‐based solid‐state cathode and a DME/LiFSI/hydrofluoroether‐based anolyte concept – in coin cells and first pouch cells. This disruptive approach enables projected specific energies higher than 600 Wh kg−1 at cell stack level.

Rechargeable zinc-water battery for sustainable hydrogen generation

Metal-water primary batteries hold promise for distributed hydrogen production but suffer from limited renewability of metal electrodes in aqueous electrolytes. Here, we introduce a novel concept of a rechargeable zinc-water battery featuring a reversible zinc anode paired with a bifunctional water electrolysis electrode, realized in a specially designed aqueous electrolyte-a mild zinc triflate aqueous electrolyte with the addition of ethylenediaminetetraacetic acid disodium (EDTANa2). The system enables high-purity hydrogen production during discharge and high-purity oxygen production during charge in a membrane-free setup. In the zinc-water battery, EDTANa2 enhances the water-splitting electrode's performance by replacing hydrophobic OTF- anions, ensuring optimal water activity. Additionally, EDTANa2 enhances Zn electrode reversibility by chelating Zn2+, preventing solvated water decomposition during zinc deposition. This integrated battery continuously undergoes charge-discharge cycles for over 55 h at a current density of 6 mA cm-2. Moreover, it achieves a high hydrogen evolution rate of 12.5 mL cm-2 h-1, enabling cost-effective, high-purity hydrogen production without expensive membranes. These findings open new avenues for sustainable hydrogen generation and energy storage in nano energy systems.

External Pressure in Polymer-Based Lithium Metal Batteries: An Often-Neglected Criterion When Evaluating Cycling Performance?

Solid-state batteries based on lithium metal anodes, solid electrolytes, and composite cathodes constitute a promising battery concept for achieving high energy density. Charge carrier transport within the cells is governed by solid-solid contacts, emphasizing the importance of well-designed interfaces. A key parameter for enhancing the interfacial contacts among electrode active materials and electrolytes comprises externally applied pressure onto the cell stack, particularly in the case of ceramic electrolytes. Reports exploring the impact of external pressure on polymer-based cells are, however, scarce due to overall better wetting behavior. In this work, the consequences of externally applied pressure in view of key performance indicators, including cell longevity, rate capability, and limiting current density in single-layer pouch-type NMC622||Li cells, are evaluated employing cross-linked poly(ethylene oxide), xPEO, and cross-linked cyclodextrin grafted poly(caprolactone), xGCD-PCL. Notably, externally applied pressure substantially changes the cell's electrochemical cycling performance, strongly depending on the mechanical properties of the considered polymers. Higher external pressure potentially enhances electrode-electrolyte interfaces, thereby boosting the rate capability of pouch-type cells, despite the fact that the cell longevity may be reduced upon plastic deformation of the polymer electrolytes when passing beyond intrinsic thresholds of compressive stress. For the softer xGCD-PCL membrane, cycling of cells is only feasible in the absence of external pressure, whereas in the case of xPEO, a trade-off between enhanced rate capability and minimal membrane deformation is achieved at cell pressures of ≤0.43 MPa, which is considerably lower and more practical compared to cells employing ceramic electrolytes with ≥5 MPa external pressure.

An Innovative Concept of Membrane-Free Redox Flow Batteries with Near-Zero Contact Distance Between Electrodes.

Given that the ion-exchange membrane takes up more than 30% of redox flow battery (RFB) cost, considerable cost reduction is anticipated with the membrane-free design. However, eliminating the membrane/separator would expose the membrane-free RFBs to a higher risk of short-circuits, and the dendrite growth may aggravate this issue. The current strategy based on expanding distances between electrodes is proposed to address short-circuit issues. Nevertheless, this approach would decrease the energy efficiency (EE) and could not restrain dendrite growth fundamentally. Herein, an inexpensive and electron-insulating boron nitride nanosheets (BNNSs)-Nylon hybrid interlayer (BN/Nylon) is developed for general membrane-free RFBs to achieve "near-zero distance" contact between electrodes. And the Lewis acid sites (B atoms) in BNNS can interact with the Lewis base anions in electrolytes, enabling a reduced Pb2+concentration gradient. Additionally, the ultrahigh thermal conductivity and mechanical strength of BNNSs promote the uniform plating/stripping process of Pb and PbO2. Compared with conventional soluble lead RFBs, introducing BN/Nylon interlayers boosts EE by ≈38.2% at 25mAcm-2, and extends the cycle life to 100 cycles. This innovative strategy premieres the application of the BN/Nylon interlayer concept, offering a novel perspective for the development of general membrane-free RFBs.

Improved plating/stripping in anode-free lithium metal batteries through electrodeposition of lithiophilic zinc thin films

The new concept of anode-free Li batteries (AFLBs) with no excess lithium, while retaining numerous strengths, does come with certain challenges, such as high capacity loss and low coulombic efficiency. These challenges can be addressed through the utilization of modified lithiophilic current collectors to enhance the electrochemical performances. Herein, we investigated the surface modification of the Cu current collector by zinc electrodeposition to provide a lithiophilic thin layer. This process aims to facilitate a smoother plating/stripping process, leading to a uniform and dendrite-free lithium deposition on the LixZny phase formed at the first stages of plating. The zinc-modified current collectors improved cell's performances, including smooth and dense lithium deposition, reduced overpotential at various applied current densities (44.5 mV to 16.8 mV @0.25 mA cm−2), prolonged cycling stability for about 300 cycles and provided high coulombic efficiency of 95 % when compared to bare Cu electrodes. These improvements are attributed to a favorable lithium alloying reaction on the Zn-coated surface. Galvanostatic Intermittent Titration Technique (GITT) and Electrochemical Impedance Spectroscopy (EIS) revealed high diffusion coefficients for lithium (ranging from 10−9 to 10−6 cm² s-1), despite of the solid-state Li diffusion in the Zn film coating. We anticipate that implementing this modified current collector in a half-cell configuration could lead to the realization of a high-performance, anode-free lithium battery. This holistic approach proposes a scalable and cost-effective technique for boosting the performance of AFLBs.

Direct solar energy conversion on zinc–air battery

A concept of solar energy convertible zinc-air battery (SZAB) is demonstrated through rational design of an electrode coupled with multifunction. The multifunctional electrode is fabricated using nitrogen-substituted graphdiyne (N-GDY) with large π-conjugated carbonous network, which can work as photoresponsive bifunctional electrocatalyst, enabling a sunlight-promoted process through efficient injection of photoelectrons into the conduction band of N-GDY. SZAB enables direct conversion and storage of solar energy during the charging process. Such a battery exhibits a lowered charge voltage under illumination, corresponding to a high energy efficiency of 90.4% and electric energy saving of 30.3%. The battery can display a power conversion efficiency as high as 1.02%. Density functional theory calculations reveal that the photopromoted oxygen evolution reaction kinetics originates from the transition from the alkyne bonds to double bonds caused by the transfer of excited electrons, which changes the position of highest occupied molecular orbital and lowest unoccupied molecular orbital, thus greatly promoting the formation of intermediates to the conversion process. Our findings provide conceptual and experimental confirmation that batteries are charged directly from solar energy without the external solar cells, providing a way to manufacture future energy devices.

Conceptual design and numerical analysis of a miscibility gap alloy-based solid-state thermal battery for electric vehicles

Heating the passenger cabin of electric vehicles at low temperatures consumes a large amount of battery power, resulting in a significant reduction in cruising range. On-board thermal energy storage is an effective way to improve the cruising range of electric vehicles in winter. Miscibility gap alloy is a new type of shape-stabilized composite phase change material, which has the advantages of high energy storage density, high thermal conductivity, low cost, and good safety. Therefore, using it to heat electric vehicles can increase their cruising range, prolong battery life, and reduce cost. In this paper, the concept of a compact on-board solid-state thermal battery based on miscibility gap alloy is proposed for the first time, and the heat charging, thermal insulation and heat discharging performance of the design are analysed based on numerical simulations. The results show that the thermal battery can reach a heat storage density of 553.8 Wh/L, and the average heat discharging power can reach 1.326 kW. The results of this paper can provide guidance for the engineering development of miscibility gap alloy-based solid-state thermal batteries.

The micro black hole cellular battery: The ultimate limits of battery energy density

With the clean energy revolution, many methods of energy production, such as solar and wind power, are quite unstable because of weather variability. However, energy consumption remains relatively stable. Therefore, efficient energy storage could be crucial for the future. In this context, we will explore the theoretical limits of battery efficiency in terms of energy density. Surprisingly, although quite speculative, a potential solution might involve a cellular battery composed of micro black holes. In fact, let us suppose hypothetically that advanced future technology can handle the formation of black holes. Then, according to the extremal solution of the Reissner–Nordström metric from general relativity, such a battery could be stable and would not collapse into a larger black hole because the electromagnetic repulsion would precisely offset the force of gravity. Additionally, although it is generally assumed that nothing can escape from a black hole, a micro black hole could possibly annihilate another micro black hole, resulting in the release of an enormous amount of clean energy. For example, a battery weighing just one kilogram could provide approximately 470 million times the energy of the most efficient 200-kilogram lithium battery at the time of writing. While achieving such a level of technological advancement is certainly not imminent, it is not inconceivable that battery technology development could follow a trajectory similar to that of computer technology. Just as breakthroughs in physics and computer engineering have led to exponential growth in computer efficiency in the last 50 years, it is possible that battery efficiency could double or even quadruple every few years following different types of breakthroughs. Nonetheless, the theoretical concept of a micro black hole battery appears to align with current predictions of fundamental physics regarding the ultimate physical limits on energy density storage. This strongly indicates we are at the very early stage of battery technology, not even close to the end.

The Impact of Structural Pattern Types on the Electrochemical Performance of Ultra-Thick NMC 622 Electrodes for Lithium-Ion Batteries

An increase in the energy density on the cell level while maintaining a high power density can be realized by combining thick-film electrodes and the 3D battery concept. The effect of laser structuring using different pattern types on the electrochemical performance was studied. For this purpose, LiNi0.6Mn0.2Co0.2O2 (NMC 622) thick-film cathodes were prepared with a PVDF binder and were afterward structured using ultrafast laser ablation. Eight different pattern types were realized, which are lines, grids, holes, hexagonal structures, and their respective combinations. In addition, the mass loss caused by laser ablation was kept the same regardless of the pattern type. The laser-structured electrodes were assembled in coin cells and subsequently electrochemically characterized. It was found that when discharging the cells for durations of less than 2 h, a significant, positive impact of laser patterning on the electrochemical cell performance was observed. For example, when discharging was performed for one hour, cells containing laser-patterned electrodes with different structure types exhibited a specific capacity increase of up to 70 mAh/g in contrast to the reference ones. Although cells with a hole-patterned electrode exhibited a minimum capacity increase in the rate capability analysis, the combination of holes with lines, grids, or hexagons led to further capacity increases. In addition, long-term cycle analyses demonstrated the benefits of laser patterning on the cell lifetime, while cyclic voltammetry highlighted an increase in the Li-ion diffusion kinetics in cells containing hexagonal-patterned electrodes.

Super-capacitor integration into hybrid vehicle power source

The plug-in hybrid vehicle based on the concept of battery operated vehicle with strong electrical motor(s) and electrochemical battery is for thermal comfort of crew and for occasional elongated travel range completed by generator, which is designed on average traction power only and during of journey is mainly used in co-generative run for cabin heating. Such vehicle efficiency can be improved by the third power source, specifically used only for acceleration and regenerative braking purposes. That role is optimal for super-capacitor, which has very good charging efficiency and can store the energy from braking to the next acceleration. Both these actions are usually very fast with high power in very short time. Its sizing and voltage control is investigated in this paper.

Latest progress and challenges associated with lithium-ion semi-solid flow batteries: a critical review.

Since the proposal of the concept of semi-solid flow batteries (SSFBs), SSFBs have gained increased attention as an alternative for large-scale energy storage applications. As a new type of high energy density flow battery system, lithium-ion semi-solid flow batteries (Li-SSFBs) combine the features of both flow batteries and lithium-ion batteries and show the advantages of decoupling power and capacity. Moreover, Li-SSFBs typically can achieve much higher energy density while maintaining a lower cost. Therefore, Li-SSFBs are some of the most promising technologies for future energy storage. Despite these advantages, a significant gap towards the commercialization of Li-SSFBs still exists. In this article, we have reviewed the research progress of Li-SSFBs in aqueous and non-aqueous systems in recent years. We have further discussed the future research trends and application prospects of Li-SSFBs, providing guidelines for future research in this area.

Stretchable and biodegradable plant-based redox-diffusion batteries.

The redox-diffusion (RD) battery concept introduces an environmentally friendly solution for stretchable batteries in autonomous wearable electronics. By utilising plant-based redox-active biomolecules and cellulose fibers for the electrode scaffold, separator membrane, and current collector, along with a biodegradable elastomer encapsulation, the battery design overcomes the reliance on unsustainable transition metal-based active materials and non-biodegradable elastomers used in existing stretchable batteries. Importantly, it addresses the drawback of limited attainable battery capacity, where increasing the active material loading often leads to thicker and stiffer electrodes with poor mechanical properties. The concept decouples the active material loading from the mechanical structure of the electrode, enabling high mass loadings, while retaining a skin-like young's modulus and stretchability. A stretchable ion-selective membrane facilitates the RD process, allowing two separate redox couples, while preventing crossovers. This results in a high-capacity battery cell that is both electrochemically and mechanically stable, engineered from sustainable plant-based materials. Notably, the battery components are biodegradable at the end of their life, addressing concerns of e-waste and resource depletion.

Electrochemical Performance of Lithium-Ion Pouch Cells Containing Aqueous Processed and Laser Structured Thick Film NMC 622 and Graphite Electrodes

The development of high areal energy density electrodes with layered metal oxide cathode materials is currently a hot topic in research and industry. However, for automotive applications, current research focuses on the merger of two concepts: (i) the “thick-film concept” which enables a high energy density due to a reduced amount of inactive materials, and (ii) the “three-dimensional (3D) battery concept”, which provides a high power density with improved interfacial kinetics at mass areal capacity ≥ 6.5 mAh/cm2. Latter could be realized by applying ultrafast laser patterning of electrodes which in turn includes an advanced 3D electrode design. Briefly, a rapid and homogeneous electrode wetting with liquid electrolyte can be induced, and besides a high capacity retention during long-term cycling. However, the mass loss due to laser patterning needs to be taken into account, since the cathode represents about 50 % of the total material costs of LIBs. Thus, the use of electrode structures with a high aspect ratio as well as a significantly reduced material removal is of great importance. Besides, cost reduction and environmentally friendly production by applying aqueous processing of cathode has been intensively investigated recently. In this work, 150 µm thick-film Li(Ni0.6Mn0.2Co0.2)O2 electrodes were manufactured with both water-based binders and PVDF binder by tape-casting. Both cathodes are anodes were subsequently laser patterned to achieve 3D architectures. Finally, the NMC 622 cathodes were assembled in pouch cells versus graphite anodes for studying the impact of laser patterning and binders on the electrochemical performance by applying rate capability analysis, electrochemical impedance spectroscopy (EIS), and lifetime analysis.