Charge Acceptance Research Articles

Long-Life Lead-Carbon Batteries for Stationary Energy Storage Applications.

Owing to the mature technology, natural abundance of raw materials, high recycling efficiency, cost-effectiveness, and high safety of lead-acid batteries (LABs) have received much more attention from large to medium energy storage systems for many years. Lead carbon batteries (LCBs) offer exceptional performance at the high-rate partial state of charge (HRPSoC) and higher charge acceptance than LAB, making them promising for hybrid electric vehicles and stationary energy storage applications. Despite that, adding carbon to the negative active electrode considerably enhances the electrochemical performance. However, carbon brings some adverse effects, such as the severe hydrogen evolution reaction (HER) in the NAM due to the low overpotential of carbon material, promoting severe water loss in LCBs. From a practical application point of view, the irreversible sulfation of the negative active material (NAM) and extreme shedding and softening of the positive active material (PAM) are the main obstacles for next-generation LCBs. Recently, a lead-carbon composite additive delayed the parasitic hydrogen evolution and eliminated the sulfation problem, ensuring a long life of LCBs for practical aspects. This comprehensive review outlines a brief developmental historical background of LAB, its shifting towards LCB, the failure mode of LAB, and possible potential solutions to tackle the failure problems. The detailed LCB's development towards long life was discussed in light of the reported literature to guide the researcher to date progress. More emphasis was directed toward the new applications of LCBs for stationary energy storage applications. Finally, state-of-the-art progress and further research gaps were pointed out for future work in this exciting era.

Sandwich structure of negative electrode using N-doped cellulose based carbon aerogel/graphene composite in ultra-battery

This study introduced a new ultra-battery (UB) structure by replacing N-doped monolithic carbon sheets instead of lead grids as a current collector. The carbon structure creates a sandwich construction (C|Pb|C), which serves as an alternative to lead grids and enhances the electrochemical properties of the battery. By removing lead grids, the weight of negative electrodes was reduced, and the specific capacity based on the total weight of the electrode (NAM + lead grids) increased by 1.3 times in deep discharge conditions. Additionally, the cycle life of the UB increased up to 2.35 times in HRPSoC mode. These improvements are due to the 3D and continuous conductive network path and higher charge acceptance of N-doped carbon sheets. These features facilitate the reversibility reaction of lead sulfate to lead by reducing the growth rate and size of created sulfate crystals. FESEM and X-ray analysis verified these phenomena. Linear sweep voltammetry (LSV) has shown that optimizing N-doping processes can control hydrogen evolution reaction (HER) in UBs. Furthermore, the UB's performance was improved and verified through charge/discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) tests.

Effects of High Level of Lead (II) Oxide (PbO) Usage on Accumulator and Response Surface Method

This study involved the preparation of lead oxide paste for use in the production of lead-acid batteries. The paste was applied to the positive plates, and its performance effects were tested on the battery. Morphological and surface area analyses were conducted using SEM and BET, respectively, after the performance tests. Two mixtures of lead oxide ratios, 25%Pb-75%PbO (sample A) and 30% Pb-70% PbO (sample B), were used. The dough was applied to positive grids and passed through the curing process. SEM images revealed that tribasic sulfate (3BS) structures had a higher charge acceptance rate than tetrabasic sulfate (4BS) structures. BET analyses showed that the surface area of the samples with A ratio was higher than that of B. Electrical tests were conducted in the laboratory, and the A sample was found to be 12% more effective in the first charging efficiency than the B sample. Sample A was also found to be 67% more efficient in charge acceptance tests and 6.5% more efficient in cycle tests. The study also showed that increasing the %Pb ratio in the product decreases the initial charge efficiency, charge acceptance, and cycle life. Finally, the response surface method was used to examine the 2D picture of the relationship between lead percentage and yield, and it was found that the highest yield was obtained at 26% lead yield, with the yield being inversely proportional to the increase in lead percentage, likely due to the effect of particle size and surface area.

Application of carbon fibers in thin-plate pure lead batteries

BackgroundThis research aimed to synthesize a Pb/CF cloth/Pb composite as a highly efficient lead-carbon electrode for lead-acid batteries (LAB). Degradation of lead–acid batteries (LAB) often results from intermittent renewable energy usage. The addition of carbon materials can help inhibit LAB degradation. Thin plates made of pure Pb exhibit a high hydrogen evolution overpotential and greater resistance to corrosion than Pb alloys in dilute H2SO4. Meanwhile, activated CF cloth is a monolithic, conductive, and hydrophilic material. However, carbon materials are chemically inert making the Pb/C interface with high resistance and tend to have a lower hydrogen evolution overpotential. MethodsFollowing chemical modification, activated CF cloth was used to fabricate LCF through hot pressing. The formation mechanism of LCF was then determined by analyzing the surface characteristics of the CF cloth after chemical modification. Significant findingsThe inner CFs in LCF were wetted by liquid Pb. The charge transfer resistivity (Rct) of LCF was 18.82 Ω, which is considerably lower than that of Pb (616.80 Ω). Both pure LCF and paste-type LCF AGM batteries exhibit notable charge acceptance during HRPSoC cycling. The remaining 1C capacity of paste-type LCF battery remains stable over 1000 cycles with high 1C rate charge and 3C rate discharge cycling.

Police Decisions in a Rape Scenario: The Effect of Trauma Response, Forensic Evidence, Stranger-Perpetrators, and Rape Mythology.

This study examined the direct effect of "classic rape" characteristics, and how they were moderated by rape myth endorsement, on the likelihood of arrest, perceived district attorney charge acceptance, and perceived suspect conviction using a formal rape disclosure among a sample of 468 police participants from a sizeable municipal law enforcement agency in one of the fifth largest and most diverse U.S. cities. A randomly assigned, between-subjects factorial vignette design was employed. Manipulations included stereotypical trauma response, forensic medical exam, and perpetrator type. Path modeling revealed statistically significant relations between stereotypical trauma response, forensic medical exam, perpetrator type, and the three outcome variables. Rape myth endorsement moderated the effect of manipulations on the dependent variables. Implications for research and policy are discussed.

Rational designs to enable 10-min fast charging and long cycle life in lithium-ion batteries

A daunting challenge in the design of lithium ion batteries (LiBs) is enabling 10-min extreme fast charging (XFC) while achieving appreciable charge acceptance and cycle life. This desirable outcome requires both a comprehensive understanding of LiB operation and aging behavior at different length scales and careful optimization. Lithium plating has been a critical bottleneck because, at XFC rates, it consumes cyclable lithium causing distinct aging and safety concerns even in moderate-loading LiBs. We propose combining multiple solutions, including materials-to-electrode design-to-charging protocols, that are intended to overcome limitations in lithium-ion transport in the electrolyte phase, thus enabling 10-min XFC in LiBs. Some implemented strategies include cathode chemistry, optimized carbon binder domain in the cathode, dual layer anode design, improved separator and advanced electrolyte. Further, innovative charging protocols in moderately loading (∼ 3 mAh/cm2 anode/2.7 mAh/cm2 cathode) single-layer pouch cells are proposed, together with demonstrated 10-min XFC with higher charge acceptance between 87.3 and 92.1% (or 2–2.1 mAh/cm2) for 600 cycles without lithium plating. This methodical study with well-defined cells shows promise in combining multiple solution strategies to enable 10-min XFC, charting a pathway to achieve XFC in higher-loading energy-optimized LiBs.

Dynamic Charge Acceptance Compared to Electrochemical Impedance Spectroscopy Parameters: Dependencies on Additives, State of Charge, and Prior Usage

The goal of this work was to predict the dynamic charge acceptance (DCA) for cells using different additives on the negative electrode from the evaluation of small-signal measurements by electrochemical impedance spectroscopy (EIS). Thereby, various operating points were evaluated, such as state of charge (SoC) and prior usage (charge or discharge). The 2V test cells under investigation utilized plates of enhanced flooded 3P2N battery cells (EFB). They contained three positive and two negative electrodes. The latter varied in their additive composition. In total, eight different negative electrodes were investigated, five including specially synthesized amorphous carbon as an additive, two with unknown additive mixes, and one including a commercially available carbon black. The best parameters for predicting the DCA were found within the first semicircle of the negative half-cell spectra measured during a superimposed charging current.

One pot synthesis of carbon decorated NiO nanorods as cathode materials for high-performance asymmetric supercapacitors

The composites of metal oxides and carbons are of research interest for improving the energy density of supercapacitors. In this work, we have demonstrated a simple one-pot hydrothermal synthesis method to prepare NiO nanorods followed by carbon framework decorated NiO nanorods (NiO@C). The NiO@C electrode showed an excellent specific capacitance of 1360 F g−1 compared to pristine NiO of 890 F g−1 at 1 A g−1 in a voltage range of 0.05 to 0.5 V in 1 M KOH electrolyte. The NiO@C electrodes showed excellent cycle stability over 10,000 cycles with 90 % capacitance retention. Asymmetric supercapacitors fabricated using corncob-derived activated carbon anode, and NiO@C cathode delivers a power density of 4574 W kg−1 at an energy density of 21.6 Wh kg−1. The enhanced capacitance of NiO@C material is due to the synergistic effect of the pseudocapacitive of NiO nanorods and the electric double-layer capacitance of the carbon matrix. Besides, the carbon framework facilitates quick charge acceptance, improved cycling stability, and rate capability. The cost-effective one-pot synthesis and eco-friendly NiO nanorods with easy electrode fabrication open opportunities for developing high-energy-density NiO-based supercapacitors.

Effect of participation of typical clinical pharmacists in patient medication in ICUs with different approaches: An investigation and case analysis

PurposeTo investigate and study the impact on patient recovery of pharmacists’ participation in the medication guidance and intervention of patients in intensive care units (ICUs). Patients and methodsWe analyzed the drug use and typical cases of patients in the ICU of our hospital during clinical pharmacists' consultations or active monitoring from July 2019 to December 2020. This study included a total of 292 cases, which were distributed in the following eight areas: drug adjustment based on patients with hepatic and renal insufficiency,optimisation of treatment regimens based on drug interaction, identification and intervention based on adverse drug reactions, selection of blood purification methods based on drug intoxication, infusion access adjustment based on drug compatibility, drug adjustment based on genetic testing, antibiotic dose adjustment based on pharmacokinetics/pharmacodynamics (PK/PD) and others. The main observation indexes included consultation opinion efficiency rates and acceptance rates. The acceptance rate is calculated according to the acceptance of the clinical pharmacist's opinion by the competent doctor (fully accepted, partially accepted, not accepted). Calculate the efficiency rate according to the effect of the intervention measures. Definition of effectiveness: improvement of therapeutic effect of drugs; Avoid the occurrence of potential adverse drug reactions; Avoid the occurrence of potential drug compatibility reaction (for example, adjust the infusion sequence to avoid turbidity and sedimentation in the infusion pathway). ResultsThe results showed that clinical pharmacists participated in 292 cases of consultation or active monitoring of patients in the hospital's ICU based mainly on specific patient medications, drug interactions, adverse drug reactions, blood purification therapy, drug compatibility/venous infusion pathways, blood drug concentrations/drug–gene monitoring, drug PK/PD, etc. The doctor in charge acceptance rate of the consultation advice was 88.46% (completely accepted by 59.3%, partially accepted by 30.8%), and the effective rate of the consultation was 80.2%. ConclusionBased on different purposes of intervention, the acceptance rate and efficiency rate were different. The efficiency rate with complete acceptance was significantly higher than that with partial acceptance or non-acceptance. The intervention opinions proposed by a comprehensive team in which pharmacists participate are of great help to patients and can reduce adverse reactions and medication risks. The higher the acceptance rate of their opinions, the higher the effective rate.

Development of (2D) graphene laminated electrodes to improve the performance of lead-acid energy storage devices

In the present work, studies on the performance of Graphene-laminated lead acid battery electrodes were carried out. Knowing the performance and the behavior of lead electrodes and their constituents during exposure to the electrolyte medium, sulphuric acid, is critical. An effort has been made to enhance the battery performance by coating (laminating) the electrodes with Carbon material (Graphene). The primary objective of the lamination process on the electrodes is to act as a sulfate inhibitor and to increase the performance of lead-acid batteries. The electrodes were laminated with the prepared graphene solution by an immersion technique. The morphological studies were carried out using SEM, and the elemental analysis of the coating was performed using EDAX. To examine the growth of the lead sulfate crystals on the electrode surface, the structural analysis was conducted with powder XRD. The electrochemical behavior of the laminated electrodes is compared with control batteries under similar operating conditions and was investigated by the “two-electrode system.” It is observed from the experimental results on the electrical characteristics that both (Positive and Negative) laminated electrodes and only negative laminated electrode batteries showed better performance in charge acceptance and cranking ability by 09% & 34%, respectively. The performance of batteries prepared with laminated electrodes is encouraging when compared to the control batteries against 1.29 sp. gr of H2SO4 electrolyte. These studies lay a foundation for further investigations to explore the wider utilization of 2D- Graphene lamination for developing next-generation lead-acid batteries.

El delito de nombramiento o aceptación ilegal de cargo público: apropósito de la reciente modificación de la Ley N° 31676

1. Legal background; 2. Law No. 31676; 3. The criminal type; 3.1. The protected legal good; 3.2. Active subject; 3.3. Passive subject; 3.4. Typical behavior; 3.4.1. public charge; 3.4.2. Legally unsuitable person or in whom the legal requirements do not concur; 3.4.3. The normative concept of “legal requirements”; 3.4.4. Appointment, designation, contracting, charge of public office in those who do not meet the legal requirements; 3.4.5.Illegal acceptance of charge without having the legal requirements; 4. Consummation and attempt; 5. Subjective element; 6. Authorship and participation; 7. Causes of justification

Enhanced cycle life of starter lighting ignition (SLI) type lead-acid batteries with electrolyte modified by ionic liquid.

The aim of the presented work was to improve the lifetime of lead-acid SLI (starting, lighting and ignition) batteries through electrolyte modification with ionic liquids. The conducted research included the synthesis and determination of the influence of di(hexadecyldimethylammonium) and di(octadecyldimethylammonium) sulphates on the basic parameters (capacity, cranking performance) of the starter battery as well as parameters affecting its lifetime (dynamic charge acceptance, corrosion, water consumption). It has been shown that the addition of these compounds increases corrosion resistance and reduces water consumption, resulting in an increase in cyclic durability by up to 36%. The improvement is associated with the absorption of ionic liquid molecules into the mass of lead(ii) sulphate, which was confirmed by physicochemical and electrochemical studies.

Effects of exfoliated graphite addition in ultra-trace concentration on industrial-scale lead-acid battery performance

The present investigation has the main objective to elucidate the hypothesis whether the addition of graphite nanoplatelets in ultra-trace concentrations (mg.kg-1) in negative plates are able to affect the electrochemical behavior of lead-acid batteries. The 60 Ah full scale batteries were produced in an industrial unit and assembled with three types of graphite nanoplatelets of different exfoliation intensities and in five different concentrations. Through electrical tests, it was possible to establish that certain concentrations of types of these additives are capable of increasing CCA performance, charge acceptance and PSOC cycling. The analysis of the structure (new, charged and discharged and post mortem) through SEM and evaluation of the macroporosity variation identified that the increase in electrochemical performance is associated with the structural change caused by the addition of these additives. Due to the small amounts of additives involved, the polarization is only slightly altered, signaling that the water loss is not appreciably affected. Discharge tests with constant current and interruptions reinforce the idea that the structure can be positively modified to increase electrochemical performance.

Novel imidazole-based, ionic liquid: Synthetics linked to enhancing the life cycle of lead-acid batteries

The goal of this study is to improve the performance of lead-acid batteries (LABs) 12 V–62 Ah in terms of electrical capacity, charge acceptance, cold cranking ampere (CCA), and life cycle by using novel ionic liquid (IL) based on the imidazole nucleus. The working electrode was a lead‑calcium (Pb-Ca) alloy. The IL compound (1-octyl-3-propyl-1H-imidazol-3-ium tetrafluoroborate) was chosen, for the first time, as a battery electrolyte additive. The electrical capacity increased from 78.95 to 100.98 % in the presence of IL inhibitor. Furthermore, by increasing the current from 14.06 to 16.12 at a given temperature and voltage, the battery's ability to receive and store energy increased. Also, a rise in the (CCA) by not having the voltage collapse and falling below 7.2 V after 30 s of exposure to the discharge current at 255 K. The number of charging and discharging cycles increased from 113 to 133, extending the life of the battery. Several studies, including electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM), potentiodynamic polarization (PP), and cyclic voltammetric (CV) analysis, were used to characterize the cells' electrochemical properties. The mechanism for corrosion reduction was adsorption of the IL inhibitor particles on the lead alloy's surface, forming a layer that covered the surface and closed the centers, preventing the sulfate anion attack.

EIS and Electrical Investigations on (1D) Multiwall Carbon Nanotubes as NAM Additive for Automotive Lead-Acid Battery

Currently, an application like Start-Light-Ignition (SLI) for the automotive industry prefers flooded type lead-acid energy storage and is also vastly adopted energy storage. Lead-acid cells in a battery comprise negative and positive electrodes, separated by an insulating material with industrial-grade H2SO4 as an electrolyte. The objective of the present investigation is to overcome the progressive sulphation in the negative electrode and improve the battery’s electrical performance. With one dimensional (1D) carbon nano tubes (CNTs) as an additive in the negative electrode of an automotive flooded lead-acid battery (LAB), we try to improve the battery performance. In this study, negative electrodes of LAB were prepared by loading traditional constituents like lead oxide, H2SO4, H2O, polyester binder, lignosulphonate, and Blanc Fixe while limiting MWCNTs to 0.2%. The performance studies of the prepared batteries were conducted, as per Japanese Industrial Standards (JIS). Both the batteries prepared with and without MWCNTs as an additive in negative active materials (NAM) were subjected to electrical assessments to understand the cold cranking ability, cycling stability, and charge acceptance. The batteries were also analyzed by electrochemical impedance spectroscopy (EIS) where the lower charge transfer resistance was observed with the battery having MWCNTs when compared to the control (without MWCNTs) battery. The present investigations established that the MWCNT material, as an additive, played a vital role in laying an improved conductive network across the negative electrodes for higher cycling applications (ISS/Hybrid/EV).

(Invited) Ester and Carbonate-Based Low Temperature Electrolytes for Operation of Lithium-Ion Batteries in Extreme Environments for NASA Missions

NASA continues to have an interest in developing high specific energy and high power rechargeable batteries that can operate well over a wide temperature range. Potential applications that could be enabled or enhanced by such technology include: (i) future Mars and Lunar landers, (ii) future Mars and Lunar rovers, (iii) small robotic missions, and (iv) future planetary aerial vehicles, where high specific energy, high power and wide operating temperature range is desired. Future missions to some of the distant icy moons of Jupiter and Saturn are also anticipated to benefit from improved ultra-low temperature rechargeable batteries with high specific energy.1 A number of terrestrial applications, including automotive and aviation Li-ion batteries, also benefit from having wide temperature range capability. To meet these needs, the Electrochemical Research, Technology, and Engineering Group at the Jet Propulsion Laboratory (JPL) has developed a number of low temperature Li-ion electrolytes utilizing various approaches. Broadly speaking, the performance targets of this work are to provide operation over the temperature range of +60oC to -60oC (delivering over 100 Wh/kg at -40oC at reasonable rates).This paper will provide an overview of the low temperature electrolyte development activities that have taken place at JPL, with a focus on enabling ultra-low temperature operation for extreme environments. The electrolytes evaluated included blends which contain elements of various approaches, including (i) the use of ester co-solvents, (ii) low ethylene carbonate content-based blends, (iii) the use of electrolyte additives, and (iv) the use of mixed lithium electrolyte salts. Experimental studies were performed utilizing three-electrode cells to determine the influence that the electrolyte type has upon the electrode kinetics as a function of temperature. A number of electrochemical techniques were employed to study these cells, including Electrochemical Impedance Spectroscopy (EIS), Tafel polarization, and linear micro-polarization.Improved low temperature capability has been demonstrated in small and large capacity prototype cells with a number of chemistries (i.e., NCO, NCA, NMC, LCO and LFP-based chemistries), including the ability to deliver high specific energy down to -60oC, good charge acceptance at low temperature, and high-power capability at -40oC. Prototype cells incorporating JPL developed electrolytes were obtained from a number of vendors, including (i) Eagle Pitcher Technologies-Yardney Division, (ii) Enersys/Quallion, LLC, (iii) E-One Moli Energy Ltd., (iv) Saft America, and (iv) Navitas/A123. Emphasis was devoted to establishing the charge acceptance characteristics of the cells at very low temperatures, especially below -20oC. Given that lithium plating when charging at low temperatures is a known degradation mode of Li-ion cells in general, attention was focused upon characterizing the conditions in which its likelihood may be more pronounced, determining the influence of electrolyte type, and attempting to detect its occurrence indirectly.Early generations of electrolytes have been utilized in a number of NASA missions, including the 2003 Mars Exploration Rover, 2007 Phoenix Lander, 2011 Mars Science Laboratory (MSL) Curiosity Rover, 2018 Mars InSight Lander, and a JPL/CSUN CubeSat.1-5 Previous work has also targeted improved low temperature performance of Li-ion cells for automotive applications. Current work is focused primarily upon providing higher specific energy coupled with good power characteristics at very low temperatures. Studies have also been performed demonstrating operational capability down to -90oC in some systems, and survival capability to temperatures as low as -135oC.ACKNOWLEDGEMENT The work described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA). The information in this document is pre-decisional and is provided for planning and discussion only. REFERENCES M. C. Smart, B. V. Ratnakumar, R. C. Ewell, S. Surampudi, F. Puglia, and R. Gitzendanner, Electrochimica Acta, 268, 27-40 (2018). M. C. Smart, D. Muthulingam, M. E. Lisano, S. F. Dawson, R. B. Shaw, B. T. White, A. Buonanno, C. Deroy, and R. Gitzendanner, 236th Meeting of the Electrochemical Society (ECS), Atlanta, Georgia, October 15, 2019. M. C. Smart, F. C. Krause, and J. -P. Jones, CREB Bi-Annual Meeting, University of Maryland, December 10, 2021. K. B. Chin, G. B. Bolotin, M. C. Smart, S. Katz, J. A. Flynn, N. K. Palmer, E. J. Brandon, and W. C. West, IEEE A&E Systems Magazine, 36 (5), 24-36 (2021). M. C. Smart, B. V. Ratnakumar, F. Charlie Krause, William C. West and Erik J. Brandon, 2021 Space Power Workshop (Virtual), Pasadena, CA, April 19, 2021. M. C. Smart, F. C. Krause, J. -P. Jones, C. L. Fuller, J. A. Schwartz, and B. V. Ratnakumar, 2018 Conference on Advanced Power Systems for Deep Space Exploration, Pasadena, CA, October 22-24, 2018.

Characterization of lignin and lignin-derivatives from biomass. Application as expander of Lead-acid battery

Expanders, as lignosulfonates, are crucial for a good performance of Pb/acid batteries. In the process of discharge, the Pb and the PbO2 go to PbSO4. The formed PbSO4 is adsorbed on the surface of the Pb electrode and dramatically reduces the lifetime of the battery by the formation of big PbSO4 crystals. In order to prevent that, the addition of expanders in the negative electrode is an economic solution to prevent the formation of big crystals. In this investigation, we propose the synthesis of several lignosulfonates obtained from lignin of many biomass origins. We have derivatized nine samples of lignin via microwave-assisted sulfonation, then we have characterized how efficient is the chosen synthesis method. The lignosulfonates obtained have been characterized by infrared spectroscopy (IR), proton nuclear magnetic resonance (1HNMR), two-dimensional correlated spectroscopy (COSY), and elemental analysis to acquire some relevant information about their structure in terms of functional groups. In this way, three commercial lignosulfonates, Vanisperse A, Indulin AT, and Oakwood, have been selected as references for our comparisons. Moreover, we have checked their electrochemical properties, using electrochemical techniques to compare their behavior with respect to the commercial lignosulfonates. Finally, we have selected one of them and we have tested its performance as an expander in a Pb/acid battery. That result is a very promising first approach, and we can conclude that lignosulfonates derivatives are a good and low-cost choice to improve the lifetime of Pb/acid batteries. In particular, it is shown that the incorporation of LignosB improves the cell formation as well as the first capacity (36.30% more) and the charge acceptance (63.16% more), being these relevant parameters in the performance of Pb/acid batteries.

Estimating Brake Pad Life in Regenerative Braking Intensive Vehicle Applications

<div class="section abstract"><div class="htmlview paragraph">Regenerative braking without question greatly impacts brake pad service life in the field, in most cases extending it significantly. Estimating its impact precisely has not been an overriding concern - yet - due in part to the extensive sharing of brake components between regen-intensive battery-electric and hybrid vehicles, and their more friction-brake intensive internal combustion engine powered sibling. However, a multitude of factors are elevating the need for a more accurate estimation, including the emerging of dedicated electric vehicle architectures with opportunities for optimizing the friction brake design, a sharp focus on brake particulate emissions and the role of regenerative braking, a need to make design decisions for features such as corrosion protection for brake pad and pad slide components, and the emergence of driver-facing features such as Brake Pad Life Monitoring. Tackling this question raises questions such as “is the proven braking energy and temperature based wear model still sufficiently predictive of wear or do other mechanisms become dominant?”, and “how does customer behavior for charging and discharging of the battery affect brake pad life?” In the present study, validated models for brake pad life in the field are adapted for regenerative braking equipped vehicles, including simple models for the battery charge acceptance power, battery state of charge, electric drive unit characteristics, and customer battery charging habits. After correlating with field data, the models are used in case studies to illustrate some of the important considerations for friction brake wear on regenerative brake equipped vehicles.</div></div>

(Digital Presentation) Effects of Cation Doping on the Stability and Charge Acceptance of Alpha Nickel Hydroxide for Energy Storage Applications

Nickel hydroxide is used as active material in nickel based batteries and capacitors. It has two phases which are alpha and beta, since alpha nickel hydroxide has higher capacity it attracts scientists attention. Although it has promising performance, low utilization and poor stability hinder commercialization of alpha nickel hydroxide. The most common strategy to improve stability is to dope nickel hydroxide with cobalt or aluminum. Aluminum is more prominent due to its lower price and environmental concern. Besides the stability, it is well known that discharge capacity of nickel hydroxide decreases with increasing amount of both aluminum and cobalt. Although capacity is decrasing, number of electrons which is involved in the reaction does not change with increasing amount of dopant. At the same molar doping levels, although aluminum doped samples had higher active mass (nickel) content, they had lower gravimetric capacity than cobalt doped samples. Therefore, it is not convenient to explain capacity loss by only decreasing amount of active mass.Since cobalt doping raises differences between oxygen evolution potential and oxidation potential of nickel hydroxide, it enhances chargeability of nickel hydroxide but the cyclic voltammetry results showed that higher cobalt doping causes decrease in cell voltage and energy density of battery. The results showed that higher amount of aluminum must be doped to improve stability and relatively small amount of cobalt must be used to improve chargeability of alpha nickel hydroxide. Therefore, both aluminum and cobalt are effective in improving stability but cobalt is advantageous at low doping level, as it is reported in the literature.

Electrochemical Impedance Spectroscopy as an Analytical Tool for the Prediction of the Dynamic Charge Acceptance of Lead-Acid Batteries

The subject of this study is test cells extracted from industrially manufactured automotive batteries. Each test cell either had a full set of plates or a reduced, negative-limited set of plates. With these test cells the predictability of the dynamic charge acceptance (DCA) by using electrochemical impedance spectroscopy (EIS) is investigated. Thereby, the DCA was performed according to EN 50342-6:2015 standard. The micro cycling approach was used for the EIS measurements to disregard any influencing factors from previous usage. During the evaluation, Kramers-Kronig (K-K) was used to avoid systematic errors caused by violations of the stationarity, time-invariance or linearity. Furthermore, the analysis of the distribution of relaxation times (DRT) was used to identify a usable equivalent circuit model (ECM) and starting values for the parameter prediction. For all cell types and layouts, the resistance R1, the parameter indicating the size of the first/high-frequency semicircle, is smaller for cells with higher DCA. According to the literature, this semicircle represents the charge transfer reaction, thus confirming that current-enhancing additives may decrease the pore diameter of the negative electrode.