Enhanced Energy Density Research Articles

A Promising Approach to Ultra-Flexible 1 Ah Lithium-Sulfur Batteries Using Oxygen-Functionalized Single-Walled Carbon Nanotubes.

Lithium-sulfur (Li-S) batteries represent a promising solution for achieving high energy densities exceeding 500Wh kg-1, leveraging cathode materials with theoretical energy densities up to 2600Wh kg-1. These batteries are also cost-effective, abundant, and environment-friendly. In this study, an innovative approach is proposed utilizing highly oxidized single-walled carbon nanotubes (Ox-SWCNTs) as a conductive fibrous scaffold and functional interlayer in sulfur cathodes and separators, respectively, to demonstrate large-area and ultra-flexible Li-S batteries with enhanced energy density. The free-standing sulfur cathodes in the Li-S cells exhibit high energy density maintaining 806 mAh g-1 even after 100 charge-discharge cycles. Additionally, oxygen-containing functional groups on the SWCNTs significantly improve electrochemical performance by promoting the adsorption of lithium polysulfides. Employing Ox-SWCNTs in both cathodes and interlayers, the study achieves high-capacity Li-S pouch cells that consistently deliver a capacity of 1.06 Ah and a high energy density of 909 mAh g-1 over 50 charge-discharge cycles. This strategy not only significantly enhances the electrochemical performance of Li-S batteries but also maintains excellent mechanical flexibility under severe deformation, positioning this Ox-SWCNT-based architecture as a viable, light-weight, and ultra-flexible energy storage solution suitable for commercializing rechargeable Li-S batteries.

Synthesis of MnMoO4/α-MoO3 composite materials for supercapacitor

In the quest for developing supercapacitors with enhanced energy density, we have successfully synthesized MnMoO4/MoO3 composite materials tailored for supercapacitor applications. The synthesis process utilized (NH4)6Mo7O24·4H2O and MnCl2·4H2O as precursors. The resulting composite materials were thoroughly characterized using a suite of analytical techniques, including scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, Brunauer-Emmett-Teller surface area measurements, thermogravimetric analysis, and differential scanning calorimetry. Furthermore, the supercapacitive performance of the MnMoO4/α-MoO3 composite materials was evaluated using cyclic voltammetry and constant current charge–discharge methods. The synthesis yielded an ideal composite material, with low-resistance MnMoO4 seamlessly integrated with high ion-conductive MoO3. At a current density of 3 A/g, the specific capacitance was measured at 1878.7 F/g, achieving an energy density of 260.9 Wh kg−1 and a power density of 1.448 kW kg−1. The composite materials demonstrated significant potential for the production of high-density supercapacitors.

Dynamic characteristics of pumped thermal-liquid air energy storage system: Modeling, analysis, and optimization

Pumped thermal-liquid air energy storage (PTLAES) is a novel energy storage technology that combines pumped thermal- and liquid air energy storage and eliminates the need for cold storage. However, existing studies on this system are all based on steady-state assumption, lacking dynamic analysis and optimization to better understand the system’s performance under cyclic operation. To fill this gap, the mainbody-linearized cyclic dynamic model of the PTLAES system with packed bed thermal energy storage (TES) was first developed. Then, the dynamic characteristics of the baseline system were investigated. Sensitivity analyses were carried out on TES parameters. Minimal values of levelized cost of storage (LCOS) were observed for all parameters in the range of interest. Subsequently, the TES circuit was optimized, and a triple improvement of efficiency and energy density enhancement, discharge stabilization, and cost reduction was achieved. The optimized system's round-trip efficiency and energy density increased from 61.7% to 63.1% and from 141.9 kWh/m³ to 159.2 kWh/m³, and the LCOS decreased from 163.2 $/MWh to 159.4 $/MWh. A power offset ratio lower than 3% was reached, which is the lowest value ever reported in the literature. This study provides reference for future design and operation of the PTLAES system.

Structural design and enhanced energy density of Ba0.6Sr0.4TiO3/PVDF nanocomposites with multilayer gradient structure

With the development of science and technology, the application of electronic products is extensive, and it is developing in the direction of miniaturization, integration, and high performance. However, the development of electronic products is limited due to capacitors low energy storage density. This study selects inorganic nanoparticles with high dielectric constant as fillers and polyvinylidene fluoride as the matrix of composite materials. It adopts a layer-by-layer casting method to prepare multilayer Ba0.6Sr0.4TiO3/PVDF composites. It is found that the dielectric and energy storage performances of the multilayer composites doped with Ba0.6Sr0.4TiO3 are improved compared with the pure PVDF polymer films after the electrical properties test. A multi-layer composite material with a gradient distribution of fillers was designed and prepared to improve the energy storage density. The energy storage density of multilayer composites with a favorable gradient structure can reach up to 9.3 J/cm3 at 300 kV/mm. By analyzing the improved storage density mechanism, the results show that the design of the multilayer gradient structure can significantly reduce the electric field's local concentration, inhibit the formation of conductive paths, and significantly improve the composites' energy storage density.

Enhancing energy density of graphene-based supercapacitors by redox Bisazo scaffolds

Enhancing energy density of graphene-based supercapacitors by redox Bisazo scaffolds

Development of continuous latent and sensible heat storage device with multi-energy composition for enhancing energy density

Development of continuous latent and sensible heat storage device with multi-energy composition for enhancing energy density

Realizing higher-performance supercapacitor using three-dimensional cadmium-based coordination polymer

In order to enhance energy density of supercapacitors, it is a route to develop new high-performance electrode materials. Coordination polymers (CPs) as the electrode materials of supercapacitors have received considerable attention, due to them owning redox active centers (metal ions/organic ligands) and the porosity, but developing high-performance and low-cost CP-based electrode materials remains a challenging task. Herein, a novel three-dimensional (3D) cadmium-based CP [Cd(BGPD)(H2O)2] (Cd−CP; BGPD = N,N′-bis(glycinyl)pyromellitic diimide) with low-cost has been synthesized by a facile method. When served as an electrode material of supercapacitors, in a three-electrode system, the specific capacitance of Cd−CP is up to 1339 F g−1 under 1 A g−1 (equivalent to a specific capacity of 167 mAh g−1). Notably, an asymmetrical supercapacitor, Cd−CP//rGO, as a two-electrode system constructed by the rGO electrode and the Cd−CP electrode, exhibits a superior energy density of 13.3 Wh kg−1 at 0.80 kW kg−1, and a general cycle capability with the capacitance retention of 61.3 % after 4000 cycles. Our work provides a new route for searching higher-performance electrode materials with low-cost and demonstrates the application potential of Cd−based CPs as the electrode materials of supercapacitors.

Electro‐Chemo‐Mechanical Degradation in Solid‐State Batteries: A Review of Microscale and Multiphysics Modeling

AbstractSolid‐state batteries with lithium‐metal anodes have emerged as a promising alternative to traditional lithium‐ion batteries thanks to their enhanced energy density and safety. However, the integration of solid‐state electrolytes is still hindered by mechanical instabilities caused by the rigid nature of the system. Stress and strain can be transferred at the interface between electrodes and solid electrolyte, inducing material damage during cycling. To address this issue, a comprehensive understanding of the interplay between electrochemical reactions and mechanical effects is crucial. In this article, a critical review of various approaches to model the multiphysics behavior of Li‐metal solid‐state batteries is provided by analyzing their advancements and limitations. The focus lies on workflows which simulate the effect of microstructural and material property changes on the degradation processes. Continuum modeling of three key chemo‐mechanical challenges is explored: dendritic growth from Li‐metal anodes, structural instability in composite cathodes, and solid electrolyte degradation caused by the formation of unstable interphases. The conclusion highlights the existing challenges and upcoming trends in multiphysics and microscale modeling of batteries.

4H-SiC Metalens: Mitigating Thermal Drift Effect in High-Power Laser Irradiation.

Enhancing energy density and efficiency in laser processing hinges on precise beam focusing, yet this often causes severe heat absorption and focus shifts in optical lenses. Traditional cooling methods increase cost and complexity, severely limiting versatility. Here, monolithic silicon carbide (SiC) metalens is introduced, which shows unparalleled thermal stability, integrated with a high-power laser. This metalens achieves diffraction-limited focusing with a numerical aperture (NA) of 0.5 and a focal length of 1cm. Under a 1030nm pulsed laser at 15W for 1 h, it shows a minimal temperature rise of 3.2°C and a tiny focal shift of 14µm (0.1% relative), only 6% of the shift in conventional lenses. When used to cut a 4H-SiC substrate with the same laser, the metalens exhibit only an 11.4% change in cutting depth after 1 h of operation, correlating with the focal shift results. The results unveil a groundbreaking class of compact SiC photonics devices nearly impervious to heat absorption, representing a monumental leap for high-power laser systems and opening new horizons for their applications and efficiency.

Ginkgo biloba-derived biogenic carbon quantum dots modified NiCo-LDH: Significantly enhanced energy density and cycle stability

A significant development in the usage of hydroxides in energy storage applications is the creation of LDH materials with excellent electrical conductivity and structural stability. Due to their poor electrical conductivity, bimetallic layered double hydroxides have weak rate performance and limited cycling ability. To address these issues, carbon quantum dots derived from waste Ginkgo biloba and labeled as GBC were incorporated in the preparation of NiCo-LDH. With the many oxygen-containing functional groups on the surface, GBC increases the composite's wettability while maintaining the LDH lamellar structure. It can also create localized electron-rich regions, which give the material more space and channels for electron transport, improving electrical conductivity and rate performance. Furthermore, GBC is evenly dispersed throughout the LDH skeleton, giving the composites a homogenous surface state that can mitigate the structural collapse issue brought on by the volume change during cycling. The findings demonstrate that by modulating the amount of GBC, NiCo-LDH/GBC-20 performs better electrochemically than NiCo-LDH. The capacity was 276.1 mAh g−1 at 1 A g−1, an 84.1 % improvement over NiCo-LDH. Finally, the energy density displayed by the NiCo-LDH/GBC-20//AC HSC device is 72.5 Wh kg-1 (at 798.7 W kg−1), and maintains 78.2 % of its original capacity after 12,000 cycles.

Realizing the Electrode Engineering Significance Through Porous Organic Framework Materials for High-Capacity Aqueous Zn-Alkaline Battery.

Energy storage technologies are eminently developed to address renewable energy utilization efficiently. Porous framework materials possess high surface area and pore volume, allowing for efficient ion transportation and storage. Their unique structure facilitates fast electron transfer, leading to improved battery kinetics. Porous organic framework materials like metal-organic (MOF) and covalent organic (COF) frameworks have immense potential in enhancing the charge/discharge performances of aqueous Zn-alkaline batteries. Organic frameworks and their derivatives can be modified feasibly to exhibit significant chemical stability, enabling them to tolerate the harsh battery environment. Zn-alkaline batteries can achieve enhanced energy density, longer lifespan, and improved rechargeability by incorporating MOFs and COFs, such as electrodes, separators, or electrolyte additives, into the battery architecture. The present review highlights the significant electrode design strategies based on porous framework materials for aqueous Zn-alkaline batteries, such as Zn-Ni, Zn-Mn, Zn-air, and Zn-N2/NO3 batteries. Besides, the discussion on the issues faced by the Zn anode and the essential anode design strategies to solve the issues are also included.

Pushing the Energy-Lifetime Frontier of Li-Ion Batteries: Study of Ni-Rich, Co-Free NMAW Cathode Material

Abstract Dopants and coatings have been widely used to improve the performance of Ni-rich positive electrode active materials. Previous studies have aimed to elucidate the mechanism by which Al and W improve lithium metal oxides, providing valuable insight on the design of enhanced electrode materials for Li-ion batteries. In this work, Al and W are compared as individual dopants as well as co-dopants in order to design an optimal Ni-rich, Co-free material. This involved studying the effect of synthesis temperature in the presence of Al and/or W as well as the effect that these metals have on the morphology of the resultant polycrystalline materials. In addition, structural analysis by X-ray diffraction, electrochemical analysis, and characterization of the mechanical strength of the materials were also conducted. The change in performance with the addition of Al and W depends greatly on particle size and chemical composition. Small sized Ni-rich polycrystalline particles (Ni content of 94%) with low contents of Al (3%) and W (1%) showed the greatest enhancement in energy density with good cycle life.

Thermal hazard comparison and assessment of Li-ion battery and Na-ion battery

Na-ion batteries are considered a promising next-generation battery alternative to Li-ion batteries, due to the abundant Na resources and low cost. Most efforts focus on developing new materials to enhance energy density and electrochemical performance to enable it comparable to Li-ion batteries, without considering thermal hazard of Na-ion batteries and comparison with Li-ion batteries. To address this issue, our work comprehensively compares commercial prismatic lithium iron phosphate (LFP) battery, lithium nickel cobalt manganese oxide (NCM523) battery and Na-ion battery of the same size from thermal hazard perspective using Accelerating Rate Calorimeter. The thermal hazard of the three cells is then qualitatively assessed from thermal stability, early warning and thermal runaway severity perspectives by integrating eight characteristic parameters. The Na-ion cell displays comparable thermal stability with LFP while LFP exhibits the lowest thermal runaway hazard and severity. However, the Na-ion cell displays the lowest safety venting temperature and the longest time interval between safety venting and thermal runaway, allowing the generated gas to be released as early as possible and detected in a timely manner, providing sufficient time for early warning. Finally, a database of thermal runaway characteristic temperature for Li-ion and Na-ion cells is collected and processed to delineate four thermal hazard levels for quantitative assessment. Overall, LFP cells exhibit the lowest thermal hazard, followed by the Na-ion cells and NCM523 cells. This work clarifies the thermal hazard discrepancy between the Na-ion cell and prevalent Li-ion cells, providing crucial guidance for development and application of Na-ion cell.

3D-printed Bio-inspired porous electrode by bidirectional enhancement strategy with high mass loading and enhanced energy density for supercapacitors

The effective strategy for increasing areal capacity involves the use of 3D printed thick-electrode with high mass loading. However, thick-electrode still encounters challenges such as incomplete electrolyte penetration and slow ion transport. Here, we successfully prepared lignocellulosic nanofibrils (LCNFs) from abundant bamboo biomass and developed functional ink composed of LCNFs/ carbon nanotubes (CNTs) / polyaniline (PANI) / polyvinyl alcohol (PVA) for printing. An innovative 3D printing bidirectional enhancement strategy was proposed to increase the mass loading of active materials in the vertical direction and construct ion transport channels in the transverse direction. The biomimetic porous N-doped electrode obtained after annealing treatment exhibits a more continuous conductive network, larger surface area, higher utilization of active materials, and smoother ion transport pathways compared to thick-electrode. Therefore, the Triangles biomimetic electrode exhibits an enhanced areal/specific capacitance compared to thick-electrode, reaching 5.30 F·cm−2 (184.03 F·g−1) and 4.40 F·cm−2 (122.22 F·g−1) at 2 mA·cm−2, respectively. The symmetric device demonstrates an areal capacitance of 1.34 F·cm−2 at 1 mA·cm−2 and achieves an energy density of 0.186 mWh·cm−2 at a power density of 0.49 mW·cm−2. The work provides valuable insights into the design of electrode structures for high-performance supercapacitors.

Honeycomb-like Superstructure of 3D Sodiophilic Host for Anode-Free Sodium Batteries

Sodium metal batteries (SMBs) have emerged as a promising candidate for large-scale energy storage systems due to their abundance and cost-effectiveness. However, the high reactivity of sodium (Na) inevitably leads to side reactions and it's infinite volume expansion would definitely limit the applications. The anode-free Na batteries (AFNB) significantly enhance energy density by eliminating excess sodium, but bring a few challenges in terms of cycling stability. In this study, we report that honeycomb-like Bi-nanosheets arrays vertically grown on a Cu mesh, this unique 3D superstructure accommodate the volumetric changes and provides abundant sodiophilic nucleation sites. The Na||Cu half-cell battery demonstrates high reversibility of Na plating/stripping with an average coulombic efficiency (CE) of 99.8% at high current density. The Na||Na symmetrical cell exhibits a stable cycle lifespan of over 1000 hours at a significant discharge depth (DOD) of 75%. The NaTi2(PO4)3 (NTP) cathode in AFNB cell with an N/P ratio of 1 displays an initial capacity of 95.18 mA h g-1 for 267 cycles at 1 C, with an outstanding capacity retention of 93.22%. Our work proposes a potential path toward establishing a highly sodiophilic 3D sodium host, thereby promoting its application in high-stability AFNBs.

Innovations in Biodegradable Batteries: A Sustainable Future

The increasing demand for batteries in several industries such as medical and electric car (EV) Industry has led to significant environmental challenges due to the production and disposal of traditional batteries, which are nonbiodegradable and pose risks to ecosystems. This report investigates the potential of biodegradable batteries as a sustainable alternative to traditional batteries, aiming to minimize environmental impact. This study analyzing and comparing the fiber batteries, zinc-molybdenum batteries, plant-based batteries (Flower battery), crab shell battery as well as algal biopolymers battery. It also highlights the key materials, methods for manufacture, and performance characteristics (biodegradability, energy capacity, degradation time) of each type of biodegradable batteries. The findings suggest that biodegradable batteries offer promising solutions for specific applications, such as in biomedical devices, wearable electronics, and precision agriculture, where their biocompatibility and environmental safety are crucial. Future development should focus on enhancing energy density, optimizing degradation timelines, and reducing costs to make these batteries more competitive with traditional options.

Single‐Crystalline LiMg Alloy Anode for Deep Cycling All Solid State Lithium Metal Batteries

AbstractAll solid state lithium metal batteries (ASSLMBs) with enhanced energy density has driven the exploration of Li‐alloy anodes such as Li‐Mg alloy owing to its solid‐solution structure and high theoretical specific capacity. But the Li atom diffusion limitation on Li‐Mg electrode surface further leads to sluggish atoms transport dynamics. Herein, single‐crystalline (110)‐oriented Li0.9Mg0.1 (denoted as LiMg(110)) anode is obtained by a tailored melt‐annealing procedure to tackle the above issues. Theoretical analyses and experimental results demonstrate that the crystallographic structural (110) orientation of LiMg anode can facilitate Li atom diffusion and guarantee the electrode stability during deep cycling. As a result, the LiMg(110) electrode exhibits longer cycle life with lower overpotential than polycrystalline LiMg at high current densities and areal capacities in symmetric cells. A critical current density (CCD) at the forefront of 2.5 mA cm−2 is achieved in Li3InCl6 (LIC) solid‐state system. The ASSLMB with high areal capacity (3.8 mAh cm−2), high current density (0.76 mA cm−2), and low negative/positive capacity N/P ratio (2.14) achieves exceptional cyclability over 160 cycles. The outcomes highlight a promising crystallographic regulation strategy toward practical applications of high‐performance lithium metal batteries.

Supermolecule-opitimized defect engineering of rich nitrogen-doped porous carbons for advanced zinc-ion hybrid capacitors.

Pitch-based porous carbons with adjustable surface chemical property and controllable pore structure are regarded as promising cathode materials for aqueous zinc-ion hybrid capacitors (ZIHCs), while its disordered carbon matrix and microstructure as well as insufficient surface defects often result in low Zn2+-storage capacity and poor rate capability of ZIHCs. Herein, a synergetic strategy of self-assembled supermolecule and enriched defective carbon engineering was developed to achieve ultrahigh edge-nitrogen doping for ZIHCs. The crystallite defects and surface structure of porous carbon could be effectively achieved through grafting electronegative oxygen-containing small molecules and high-level nitrogen-containing functional groups between modified polycyclic aromatic hydrocarbon and supermolecule framework. The optimized three-dimensional carbon structure delivered high capacity of 218 mAh g-1 at 0.2 A g-1, fast charge/discharge capability, enhanced energy density (165.4 Wh kg-1) and superior cycling stability (95% retention after 10000 cycles as cathode of ZIHCs). This provided new insight into the controllable synthesis of carbon cathodes for ZIHCs and expects to prepare functional porous carbon by supermolecules and special precursors.

Separator‐Supported Electrode Configuration for Ultra‐High Energy Density Lithium Secondary Battery

AbstractSignificant efforts are being made to develop high‐performance battery materials, particularly active materials. However, material‐dependent strategies for increasing energy density face challenges such as raw material costs and supply limitations, reducing their versatility to some extent. In this regard, the development of efficient battery designs can be a universal approach to increasing the energy density of lithium‐ion batteries with relatively low dependence on material properties. Herein, a novel configuration of an electrode‐separator assembly is presented, where the electrode layer is directly coated on the separator, to realize lightweight lithium‐ion batteries by removing heavy current collectors. Even on the hydrophobic separator, a poly(vinyl alcohol) binder enables uniform and scalable coating of aqueous electrode slurries through molecular interactions with the separator surface. Moreover, carbon nanotubes are utilized to reinforce the electronic conduction of the electrode, providing consistent electronic pathways regardless of SEI formation. Furthermore, owing to the superior permeability of liquid electrolytes through this electrode‐separator assembly, a multilayered electrode‐separator assembly can be suggested to further increase energy density when combined with a lithium metal anode. This lithium metal battery can achieve an areal capacity of ≈30 mAh cm−2 and an enhanced energy density of over 20% compared to conventional battery configurations.

Enhanced storage performance of a low-cost hard carbon derived from biomass

Hard Carbon is the most widely used negative electrode material for sodium-ion batteries today. Achieving high storage capacity and increasing the plateau capacity, as opposed to the sloping profile, are crucial for enhancing energy density of the full cells. While several publications address the synthesis of hard carbon, the economic viability for commercial scale-up hinges on the choice of precursors. In this study, we report the electrochemical properties of hard carbon derived from two biomass precursors, sugarcane waste (bagasse) and corn waste, and compare their performances with commercially available hard carbon. The hard carbon derived from bagasse delivers a capacity of 307 mAh/g at C/10 rate and retains approximately 234 mAh/g at 3C discharge rate. We integrate surface area, pore size distribution, Raman spectroscopy, small-angle X-ray and neutron scattering data to elucidate the sodium storage mechanism in these hard carbon samples. Correlated graphitic domains with hexagonal ordering along with fractal like agglomeration of the nanosheets are quantified. The high plateau capacity of the bagasse-derived hard carbon is attributed to the characteristic morphology and size distribution of the nanosheets and their nature of agglomeration.