Discharge Operation Research Articles

Fast-Charging Electrode Architecture Optimization through R2R Screen Printing

Creating vertical channels is a viable strategy for reducing the tortuosity and improving the charge transfer kinetics of electrodes, hence enhancing the fast-charge capacity of lithium-ion batteries (LIBs) to actualize fast-charging electrical products. Despite the fact that certain published approaches may directly render channels with electrodes without post-treatment, the control of channels’ diameter and edge distance is a challenge that may be exploited to investigate and optimize the relationship between channels and fast-charging electrodes. Moreover, the intricacy of these methods precludes their industrialization and commercialization. From the perspective of industrial and precision control channels, Roll-to-roll (R2R) screen printing is a simple, cost-effective, industrially scalable, and pattern-customizable continuous additive manufacturing approach for producing vertical channels, reducing the tortuosity of electrodes, and improving their fast-charging capabilities. Low-tortuosity electrodes manufactured by screen printing may be utilized to research the relationship between channel architecture and electrochemical performances of electrodes, as well as to boost and broaden mechanism studies and commercial applications.In this work, we first applied screen printing to design and fabricate vertical channels with a high resolution. Channel arrangements, diameters, and edge distances were meticulously developed and illustrated for LIB electrodes in order to maximize their capacity at high current rates. Applying LiNi0.6Mn0.2Co0.2O2 cathode ink, clear patterns were printed on the Aluminum substrate. By comparing and filtering, we revealed that 1) the staggered configuration enhances the high-rate charge capabilities of electrodes and 2) the channel diameter and edge distances decreasing improve the rate performances of electrodes. Specifically, at 4 and 6 C, the optimized electrode possesses a charge capacity that is two- and seven-times greater than the conventional bar-coated electrodes, respectively. In addition, neutron computed tomography demonstrated that the Li of the screen-printed electrodes was homogeneously spread along the channels during the charge and discharge operations. We believe that optimized channels accelerate ion transfer in the vertical direction, promote ion diffusion in the horizontal direction, and maximize transfer kinetics for electrodes. Although more research is required to improve the greatest resolution of screen printing technology and refine the internal design of screen-printed electrodes, R2R screen printing technology offers a new opportunity for the optimization, industrialization, and commercialization of fast-charging LIBs.

Strategies on Enabling High Areal Sulfur Loading in Lithium Sulfur Batteries

Needs for energy storage devices in modern-day applications such as electric vehicles and other high energy consuming portable electronics make the Lithium sulfur batteries (LSBs) to be one of the most attractive types since they offer a high theoretical energy density (2600 Wh kg-1), which is about an order of magnitude higher than the theoretical specific capacity of the lithium ion batteries. In addition, Sulfur is one of the most abundant materials in nature and moreover, a non-toxic element which makes the lithium sulfur battery a suitable candidate for commercialization. However, obstacles to overcome include the loss of active sulfur due to various phenomena mainly represented by polysulfide diffusion and reactivity on the lithium anode. Another serious issue observed in so many ways is the low electronic conductivity of Sulfur and its products such as Li2S as a result of cycling. These problems are often exacerbated at higher sulfur loading and lower electrolyte to sulfur ratios (E/S). One way to increase the sulfur loading is to increase the thickness of the cathode which in return increases the risk of low utilization of active material because of the high thickness and low wettability by electrolyte. Another way is to increases the ratio of the sulfur in respect to conductive host material without increasing the thickness of the cathode. By doing so, sulfur is going to fill all the pores existing in the host material and therefore, this structure cannot provide enough volume expansion during discharge process and as a result, the cathode structure may collapse and the whole cell fail. Therefore, to come up with a high performance and stable battery during cycling, there is no doubt that we have to focus on the structure of the cathode and the host material to effectively confine the sulfur and produced polysulfide and at the same time, alleviate the way of the electron transfer through the conductive network.In this research, we investigate some of the most influential parameters mainly associated with the morphology of the cathode to improve capacity retention. Optimizing the sulfur loading, E/S content, pore structure and pore volume, and the thickness of the cathode lead to an overarching understanding of the physical transitions that occur during the discharge and charge operation of the battery. In addition, various electrochemical testing to evaluation the loss of activity of the cathode surface is also carried it to correlate to the proposed physical model.

Voltage Differential Analysis during Power Discharge Operation in Energy Storage Systems

Constant Power Discharge (CPD) is a lucrative operating mode for grid-tied ESS in many energy markets. The CPD mode corresponds to an increasing current drawn as the ESS discharges. The operation can be modeled with an aged anode and cathode open circuit potentials (OCPn/p+RRC) model that can let us identify electrode-level (eSOH) parameters and resistance growth even though we do not have slow discharge with Constant Current. This identification process from realistic ESS field data, namely constant power discharge, will enable continuous eSOH diagnostics and lead to real-time and operando quantification of loss of active material and loss of lithium inventory (LAM and LLI, respectively).In addition, the timing of when the cell groups' differential voltage peaks occur when the battery system is under constant power operations inform us about the imbalance among cell groups in a module of a battery system, as shown in the figure. Using the time separation among cell differential voltage peaks as a metric of cell imbalance can improve cell balancing algorithms that measure cell imbalance using maximum or minimum voltage, which can be directly affected by the power limits of the battery system.The efficacy of the proposed algorithms is evaluated for multi-cell modules consisting of NMC/graphite cells, operating as part of a large-scale grid-connected energy storage system. Ultimately, by enabling improved diagnostics of the state of health of individual cells in a battery system and improved cell balancing algorithms, this work will enhance the performance and safety of large-scale lithium-ion battery systems. Figure 1

A technical feasibility study of a liquid carbon dioxide energy storage system: Integrated component design and off-design performance analysis

Liquid carbon dioxide (CO2) energy storage (LCES) system is emerging as a promising solution for high energy storage density and smooth power fluctuations. This paper investigates the design and off-design performances of a LCES system under different operation strategies to reveal the coupling matching regulation mechanism of the charging and discharging processes. An off-design performance prediction model is developed based on preliminary designs of turbomachinery components and heat exchangers to evaluate the feasibility of the LCES system. The performances of the charging and discharging processes are analyzed under different load levels with two operation strategies: constant pressure charging and constant pressure discharging (CP-CP) operation strategy, and constant pressure charging and sliding pressure discharging (CP-SP) operation strategy. Results show that the LCES system has a round trip efficiency of 61.83% and an energy storage density of 21.92 kW·h·m−3 under the rated condition. As the input load level increases from 80% to 120%, the maximum charging time of the system decreases from 5.15 h to 3.36 h under the constant pressure operation strategy. When the output load level increases from 70% to 120%, the maximum discharging time of the system decreases from 5.48 h to 3.31 h under the constant pressure operation strategy and from 5.60 h to 3.30 h under the sliding pressure operation strategy. Besides, the round trip efficiency of the LCES system increases first and then decreases as both input and output load levels rise, while the energy storage density of the system follows a parabolic curve only with an increase in the output load levels. For better system performance, the CP-SP operation strategy and CP-CP operation strategy are more suitable for the system with output load levels of 70–100% and 100–120%, respectively. These achievements will provide a valuable reference for the stable operation of the LCES under off-design conditions.

Investigating the efficiency of a novel combined Direct/Indirect thermal management system in optimizing the thermal performance of a new generation 46800-type LIB pack

Although the 46800-type Li-ion batteries have superior attributes, including high driving range, energy density, and fast charging capability, it is plagued by higher heat generation during discharge impacting performance, efficiency, and lifespan. To address this problem, a novel thermal management system is proposed utilizing direct/indirect liquid cooling with water, CuO nanofluid, and HFE-7100. Meshed separator plates are developed in the direct cooling channel to improve thermal uniformity and mitigate hot spots on LIBs. The numerical evaluation considers effects such as C-rate, coolant, separator wall, flow rates, flow direction, and ambient temperature on the thermal performance of the LIB pack. During a 3C discharge operation, compared to 1C, the LIB pack experiences a 7 °C increase in maximum temperature and a 4.1 °C temperature difference. However, with a 4% CuO nanofluid, these values decrease by 4.9 °C and 3 °C respectively, compared to water. A circular meshed separator wall improved the thermal performance of the battery pack by 22.7% compared to the non-wall condition. The inflow velocities of the direct and indirect cooling channels are increased from 0.2 to 0.3 m/s and from 0.1 to 0.2 m/s, respectively, which led to the 11.5% enhancement of the LIB pack’s thermal efficiency. Finally, the thermal performance of the proposed cooling system is assessed by considering various ambient temperatures ranging from 25 °C to 40 °C for the LIB pack. The results indicated that the optimized cooling system can maintain the maximum temperature of the LIB pack below 40 °C, even at an ambient temperature of 35 °C.

ChatGPT in Plastic and Reconstructive Surgery.

Background Chat Generative Pre-Trained Transformer (ChatGPT) is a versatile large language model-based generative artificial intelligence. It is proficient in a variety of tasks from drafting emails to coding to composing music to passing medical licensing exams. While the potential role of ChatGPT in plastic surgery is promising, evidence-based research is needed to guide its implementation in practice. Methods This review aims to summarize the literature surrounding ChatGPT's use in plastic surgery. Results A literature search revealed several applications for ChatGPT in the field of plastic surgery, including the ability to create academic literature and to aid the production of research. However, the ethical implications of using such chatbots in scientific writing requires careful consideration. ChatGPT can also generate high-quality patient discharge summaries and operation notes within seconds, freeing up busy junior doctors to complete other tasks. However, currently clinical information must still be manually inputted, and clinicians must consider data privacy implications. Its use in aiding patient communication and education and training is also widely documented in the literature. However, questions have been raised over the accuracy of answers generated given that current versions of ChatGPT cannot access the most up-to-date sources. Conclusions While one must be aware of its shortcomings, ChatGPT is a useful tool for plastic surgeons to improve productivity for a range of tasks from manuscript preparation to healthcare communication generation to drafting teaching sessions to studying and learning. As access improves and technology becomes more refined, surely more uses for ChatGPT in plastic surgery will become apparent.

Morphodynamic modelling of an alluvial river controlled by dam discharge and barrage operation: a study on Durgapur Barrage, India

ABSTRACT Reservoirs and barrages , built across alluvial rivers throughout the world, are losing their storage capacity at an estimated rate of about 1% annually. The pond area of Durgapur Barrage on River Damodar, India, controlled by barrage-gates is no exception. In spite of its service for more than 60 years through judicious gate-operation schedule, it is found that 52% of initial storage capacity Pond has been lost since its inception in 1956. A morphodynamic study of the alluvial Damodar River, extending from Maithon and Panchet dams at upstream to Durgapur Barrage in the downstream, has been done using a numerical model of MIKE-11. Hydrometeorological data of Damodar-Barakar River basin were used to simulate hydrodynamic and sediment transport models for ascertaining annual rate of erosion and deposition during the period 1956–2016. Study shows that about 6 million M3 sediment were transported from catchment through Dam-discharge, a part of which got deposited in the river bed while the remaining 4.9 million M3 washed away downstream through Barrage gates. Although the rate of deposition in the pond area was initially higher during the period 1956–1985, which has subsequently reduced . However, daily deposition increased more or less linearly with the increase in discharge of the river.

Advanced ECMS for Hybrid Electric Heavy-Duty Trucks with Predictive Battery Discharge and Adaptive Operating Strategy under Real Driving Conditions

To fulfil the CO2 emission reduction targets of the European Union (EU), heavy-duty (HD) trucks need to operate 15% more efficiently by 2025 and 30% by 2030. Their electrification is necessary as conventional HD trucks are already optimized for the long-haul application. The resulting hybrid electric vehicle (HEV) truck gains most of the fuel saving potential by the recuperation of potential energy and its consecutive utilization. The key to utilizing the full potential of HEV-HD trucks is to maximize the amount of recuperated energy and ensure its intelligent usage while keeping the operating point of the internal combustion engine as efficient as possible. To achieve this goal, an intelligent energy management strategy (EMS) based on ECMS is developed for a parallel HEV-HD truck which uses predictive discharge of the battery and adaptive operating strategy regarding the height profile and the vehicle mass. The presented EMS can reproduce the global optimal operating strategy over long phases and lead to a fuel saving potential of up to 2% compared with a heuristic strategy. Furthermore, the fuel saving potential is correlated with the investigated boundary conditions to deepen the understanding of the impact of intelligent EMS for HEV-HD trucks.

Key Modes of Ignition and Maintenance of Corona Discharge in Air

Theoretical and experimental studies of various modes of corona discharge operation in atmospheric pressure air are presented in this short review. The original results of modeling negative corona discharges are presented, taking into account the non-stationary plasma-chemical kinetics of charged particles in air plasma. The space–time evolution of the discharge in needle-to-plane geometry is investigated and analyzed. Several stages of discharge development are revealed from the moment of initiation of a low-negative current corona to the quasi-stationary mode of a glow discharge. Experimental data of the authors are presented. Modern technology and diagnostic equipment with a wide variation of the main parameters (the shape and polarity of the applied voltage, the type of gap, etc.) was used. The measurement of the optical characteristics of the plasma glow was carried out with high spatial resolution. Corona discharge current pulse profiles in the air at atmospheric pressure have been recorded with subnanosecond time resolution. With a positive polarity of the pin electrode and high voltage, a transition from a spherical streamer initiating a corona discharge to a cylindrical streamer is shown. The author’s results are rigorously evaluated through a critical comparison with findings from other research groups.

Optimization on high-pressure side of pump-turbine runner based on high efficiency and stability criterion via multi-objective genetic algorithm method

Pumped storage power plants are doomed to play a more important role in peak-valley shifting hence the demand for operation stability is gradually regarded as an equal important criterion as high efficiency. In our paper, new concepts, namely “swept,” “bowed (lean),” and “twisted” are introduced to systematic innovative design the geometry of high-pressure side (HPS) of a pump-turbine runner. Thereafter, a multi-objective optimization process, which consists of design of experiment (DoE), meta model generation, multi-objective genetic algorithm (MOGA), self-organization map (SOM) and takes both high efficiency and stability discipline into account is produced. The final optimization plan is selected and testified numerically. Compared to the original runner, the efficiency is improved from 91.7% to 91.9% at pump mode and improved from 92.3% to 92.8% at turbine mode. Moreover, the S margin is increased from 89.34° to 90.23° at small GVO and increased from 79.56° to 80.29° at large GVO. Besides, hump unsteady region is completely eliminated. Moreover, the flow characteristic comparation is conducted based on local hydraulic loss rate (LHLR) method. For design points, the optimized runner obviously decreases the hydraulic loss in hub and middle part of runner domain for turbine mode and slightly decrease the hydraulic loss in stay vane region for pump mode. For unsteady characteristics, HPS can better adjust the hydraulic loss distribution in corresponding discharge operating points, largely decreasing S unsteady characteristic in turbine mode and eliminating hump unsteady characteristic in pump mode. We believe that the methods proposed in our paper can bring the design of hydraulic machinery to a new level.

NiCo alloy‐anchored self‐supporting carbon foam as a bifunctional oxygen electrode for rechargeable and flexible Zn–air batteries

AbstractThe design and fabrication of flexible, porous, conductive electrodes with customizable functions become the prime challenge in the development of new‐generation wearable electronics, especially for rechargeable batteries. Here, the NiCo bialloy particulate catalyst‐loaded self‐supporting carbon foam framework (NiCo@SCF) as a flexible electrode has been fabricated through one facile adsorption‐pyrolysis method using a commercial melamine foam. Compared with the electrode with Pt/C and Ir/C benchmark catalysts, the NiCo@SCF electrode exhibited superior bifunctional electrocatalytic performance in alkaline media with a half‐wave potential of 0.906 V for oxygen reduction reaction, an overpotential of 286 mV at j = 10 mA cm−2 for oxygen evolution reaction, and stable bifunctional performance with a small degradation after 20,000 voltammetric cycles. The as‐assembled aqueous zinc–air battery (ZAB) with NiCo@SCF as a self‐supporting air cathode demonstrated a high peak power density of 178.6 mW cm−2 at a current density of 10 mA cm−2 and a stable voltage gap of 0.94 V over a 540 h charge−discharge operation. Remarkably, the as‐assembled flexible solid‐state ZAB with self‐supporting NiCo@SCF as the air cathode presented an engaging peak power density of 80.1 mW cm−2 and excellent durability of 95 h undisrupted operation, showing promise for the design of wearable ZAB. The demonstrated electrode fabrication approach exemplifies a facile, large‐scale avenue toward functional electrodes, potentially extendable to other wearable electronics for broader applications.

In situ observation of the formation and relaxation processes of concentration gradients in a lithium bis(fluorosulfonyl) amide–tetraglyme solvate ionic liquid using digital holographic interference microscopy

Next-generation Li-ion batteries (LIBs) require fast charge–discharge operations, during which a steep concentration gradient (CG) is formed between the two electrodes. The formation of a concentration profile between the electrodes in a LIB with a solvate ionic liquid is observed at a distance of less than 1 mm using holographic interferometry. This in situ technique enables the visualization of concentration profile formation near both electrodes during electrolysis, which relaxes after the electrolysis is stopped. The diffusion coefficients near both the electrodes are calculated from the concentrations of transient species near the electrode surfaces. The diffusion coefficient is smaller on the anode side of the cell than on the cathode side owing to the viscosity of the electrolyte in the diffusion layer. This viscosity effect may have caused the concentration profile to become asymmetrical during the relaxation of the CG.

Urinary schistosomiasis: risk factors and symptoms among school adolescents in Kaduna State, Nigeria

Improper waste disposal, unsafe water and indiscriminate water-contact activities are major factors enhancing continuous spread of schistosomiasis in Nigeria. Many water bodies are prone to contamination with human wastes directly discharged into them or due to surface runoff, and are infested with parasites. Open defecation and discharge of household sewage into water channels is still practiced. Children conduct activities in these water bodies, thereby exposing themselves to infections with schistomes among other pathogens. Urine samples (10 mL each) were collected from 600 consented school adolescents across six Local Government Areas of Kaduna State, Nigeria. Information on their water-contact activities were obtained by means of questionnaires. Urine sediment was examined for Schistosoma haematobium eggs by microscopy. No infection was recorded in adolescents who had awareness about the disease. Those who engaged in swimming (9.2 %, OR=2.2) and fishing (10.3 %, OR=2.1) were significantly more infected than those who did not (P≤0.05). Adolescents who worked on irrigated farms (9.0 %, OR=1.4), washed clothes in rivers (9.0 %, OR=1.6), or fetch water from rivers for domestic purpose (10.0 %) were more infected than others who did not engage in those activities. Therefore, swimming and fishing are important factors enhancing the spread of schistosomiasis among school adolescents in Kaduna State. Irrigation farming, washing of clothes in rivers or fetching water from rivers exposed the adolescents to schistosome infections. Widespread awareness campaigns, provision safe water to communities, and standard water-based recreational centers are paramount

Long-Range Regulation of Se Doping for Oxygen Reduction of Atomically Dispersed Sb Catalysts for Ultralow-Temperature Solid-State Zn–Air Batteries

Regulating the p-orbital valence electrons of atomically dispersed main-group metals to improve the inherent electrocatalytic activity has attracted extensive concerns. Herein, we designed and synthesized an atomically dispersed Sb–SeNC catalyst containing SbN2C2 and SeC2 structures, which have been identified by X-ray absorption spectroscopy and density functional theory (DFT) calculations. Sb–SeNC exhibits a high activity for the oxygen reduction reaction (ORR), and a Sb–SeNC-based flexible solid-state zinc–air battery (ZAB) can work efficiently at −40 °C, with a peak power density of 54.1 mW cm–2 and a rate discharge operation of about 44 h. DFT calculations further confirm the long-range regulation mechanism of the SeC2 moiety for the ORR of SbN2C2 and obtain the volcano relationship of Uonset vs the Se–N distance. When the Se–N distance is 7.4 Å, the adsorption ability of active site Sb can be regulated to an optimal state related to the RDS: *O → *OH, while the smaller Se–N distance in short-range would lead to the excessive attenuation of adsorption ability of active site and decrease of ORR activity, which therefore yields the long-range regulation effect of Se doping on the ORR activity of SbN2C2. This long-range regulation strategy may provide a promising approach to boost the catalytic activity of main-group metal catalysts to achieve its application in ultralow-temperature solid-state ZABs.

Validation of non-equilibrium kinetics in CO2–N2 plasmas

This work explores the effect of N2 addition on CO2 dissociation and on the vibrational kinetics of CO2 and CO under various non-equilibrium plasma conditions. A self-consistent kinetic model, previously validated for pure CO2 and CO2–O2 discharges, is further extended by adding the kinetics of N2. The vibrational kinetics considered include levels up to v = 10 for CO, v= 59 for N2 and up to v 1= 2 and v 2= v 3= 5, respectively for the symmetric stretch, bending and asymmetric stretch modes of CO2, and account for electron-impact excitation and de-excitation (e–V), vibration-to-translation (V–T) and vibration-to-vibration energy exchange (V–V) processes. The kinetic scheme is validated by comparing the model predictions with recent experimental data measured in a DC glow discharge operating in pure CO2 and in CO2–N2 mixtures, at pressures in the range 0.6–4 Torr (80.00–533.33 Pa) and a current of 50 mA. The experimental results show a higher vibrational temperature of the different modes of CO2 and CO and an increased dissociation fraction of CO2, that can reach values as high as 70%, when N2 is added to the plasma. On the one hand, the simulations suggest that the former effect is the result of the CO2–N2 and CO–N2 V–V transfers and the reduction of quenching due to the decrease of atomic oxygen concentration; on the other hand, the dilution of CO2 and dissociation products, CO and O2, reduces the importance of back reactions and contributes to the higher CO2 dissociation fraction with increased N2 content in the mixture, while the N2(B3Πg) electronically excited state further enhances the CO2 dissociation.

Nanosecond pulse breakdown in noble gases

The results of the investigation of the breakdown characteristics of the planar “open” discharge and open discharge with the generation of counter-propagating electron beams under excitation by pulses with nanosecond rise fronts are presented. The amplitude parameters of current and voltage and temporal characteristics of breakdown in helium, neon, and argon were measured. It is demonstrated that the breakdown in the open discharge is characterized by considerably larger electric field strengths at the same development delays as in the avalanche discharge. A similarity criterion based on the photoemission mechanism of electron generation, according to which the discharge development delay is inversely proportional to the squared working gas pressure, is obtained.

How to Measure Solid State Lithium-ion Diffusion using the Atlung Method for Intercalant Diffusion

A systematic investigation of the factors that affect lithium diffusion coefficient measurements in the Atlung Method for Intercalant Diffusion (AMID) is carried out. Single crystal LiNi0.6Mn0.2Co0.2O2 is used for method development. The factors include electrode mass loading, separator thickness, electrolyte solvent choice and salt molarity, voltage interval sizes, open circuit relaxation time, C-rate choice, and charge vs discharge direction. In an ideal diffusivity measurement method, none of these factors listed should impact the true material diffusivity since it should be a purely material property. However, as we demonstrate here, all these experimental parameters should be selected carefully to minimize cell and electrode resistance contributions so that one can measure true lithium diffusivity in a material that is independent of current direction. We propose a low electrode loading cell design that is applicable for all diffusion measurement methods consisting of an ultrathin electrode coating (0.2 mAh cm−2), thin separator and 1.5 M LiPF6 ethylene carbonate: dimethyl carbonate 1:1 electrolyte. Additionally, we show diffusivity is not dependent on charge or discharge direction in NMC622, and we compare AMID results to Galvanostatic Intermittent Titration. Specific to AMID 15 min OCV time with 0.1 V intervals are suitable for this measurement.

The performance evaluation of pleated electret filters enhanced by electrostatic enhanced method

The filtration efficiency deterioration over operating time due to exposure to particles, organic solvents and other factors is an obvious defect of electret filter, especially during the coronavirus pandemic. Electrostatic enhanced method has been proposed as a promising way to improve the filtration efficiency and service time of electret filters without increasing the pressure drop. In this work, the effect of discharge electrode structure and operation mode of the electrostatic enhanced structure(EES) on the filtration efficiency of commercial pleated electret filters were studied firstly, then the EES was installed in a special designed prototype air purifier, two key indicators of air purifiers(clean air delivery rate (CADR) and cumulate clean mass (CCM)) were tested to evaluate the actual performance improvement of electret filters by the electrostatic enhanced method. It was found that the discharge electrode structure had significant influence on the filtration efficiency and multi-wire array electrode was more suitable for the discharge electrode to pleated filter to ground mesh structure used in this paper. The decayed electrostatic charges of pleated electret filter cannot be recharged again through the EES in actual operation condition. The filtration efficiency improvement of the test pleated electret filters was dominantly contributed by particle charging. The filter polarizing induced by the external electric field was helpful in increasing the filtration efficiency when the particles were charged while its effect on uncharged particles was almost negligible. Besides, the actual performance of the prototype air purifier indicated that the EES can alleviate the filtration efficiency deterioration of test electret filters and extend the service life of H11 and H13 filters by more than 3 and 1.5 times respectively according to the CCM test results.

Investigations on anomalous behavior of ionic conductivity in NaPF6 salt loaded hydroxyethyl cellulose biodegradable polymer electrolyte for energy storage applications

AbstractThis article investigates the influence of NaPF6 salt content (0–30 wt.% in a varying interval of 5 wt.%) on the structural, electrical, and biodegradable properties of HEC/NaPF6 solid biopolymer electrolyte (SBE) films. The interaction of salt with the HEC polymer matrix is confirmed by FTIR and SEM studies. The elemental composition and mapping confirm the appearance of NaPF6 moieties in the HEC polymer matrix. XRD deconvolution reveals that HEC samples with 20 wt.% (H4) and 10 wt.% of salt (H2) have a significantly lower crystallinity index than pure HEC polymer. The H2 and H4 samples show the highest room temperature conductivity values (1.62 × 10−5 and 1.13 × 10−5 S cm−1, respectively) among all other prepared samples since carrier concentration influences the ionic conductivity and shares a similar order of conductivity. Thus, the H2 and H4 samples are employed as electrolyte separators in the sodium ion battery, and the results suggest that the H2‐based electrolyte system is more significant. Battery matrices like open circuit voltage (V), current density (μA cm−2), power density (mW kg−1), energy density (Wh kg−1) and discharge capacity (μA h−1) were calculated and found to be 2.48, 5.49, 44.60, 1.69, and 71.05, respectively for H2 electrolyte based cell. Wagner polarization reveals that H2 and H4 constitute the predominant charge carriers (ions) with total ion transference numbers of ⁓0.98 and ⁓0.99, respectively. To evaluate sample degradability, H2 and H4 samples were subjected to 20 and 5‐day biodegradation processes, during which the polymers completely (100%) broke down.

A Self-Stratified Thermally Regenerative Battery Using Nanoprism Cu Covering Ni Electrodes for Low-Grade Waste Heat Recovery

Developing a low-cost and high-performance thermally regenerative battery (TRB) is significant for recovering low-grade waste heat. A self-stratified TRB induced by the density difference between electrolytes is proposed to remove the commercial anion exchange membrane (AEM) and avoid ammonia crossover. The simulation and experiment results show the uneven distribution of NH3, verifying the feasibility of self-stratified electrolytes. For better power generation performance, nanoprism Cu covering Ni electrodes with a high specific surface area and a stable framework are adopted to provide more reaction active sites for fast charge transfer during discharge. A maximum power density (12.7 mW cm-2) and a theoretical heat-to-electricity conversion efficiency of 2.4% (relative to Carnot efficiency of 27.5%) are obtained in the self-stratified TRB employing nanoprism Cu covering Ni electrodes. Moreover, the cost-effectiveness, simple structure, and sustainable discharge operation indicate that it will be a potential choice for energy conversion from low-grade heat.