Battery Cycle Life Research Articles

Cloud-based system for monitoring event-based hydrological processes based on dense sensor network and NB-IoT connectivity

Hydrologists claim high-quality experimental data are required to improve the understanding of hydrological processes. Though accurate devices for measuring hydrological processes are available, the on-site deployment and operation of effective monitoring networks face many relevant issues caused by the peculiar characteristics of hydrological systems. In this manuscript, we present a self-developed system for monitoring events-based hydrological processes comprising a dense network with both soil moisture and water level gauges connected by NB-IoT technology integrated into a cloud system for near real-time gathering of information. We designed, built and calibrated the sensors and integrated them into a cloud system. We deployed them in two monitoring networks and gathered the data from several experimental runs (battery lifecycles). Results showed the suitability of the sensors and the network to properly monitor the processes solving the initial relevant issues mainly derived from connectivity issues and battery duration.

Scalable and Non-Destructive Analysis of Battery Degradation and Performance

Electrochemical processes occurring during battery operation are highly complex. Thermodynamic, kinetic and transport-based phenomena all play a significant role in the dynamic evolution of the time-based electrochemical response of any battery system. Researchers have long sought to quantify these various interconnected phenomena, but to-date elucidating the role these mechanisms play in the performance of battery systems has been challenging or impossible. To aid researchers in uncovering the mechanistic behavior of their systems, we have developed a novel testing protocol and corresponding data analysis method that is scalable and non-destructive (SAND). This protocol and analysis can be applied to any battery system, in any form factor, at any point in the battery life cycle; including R&D, manufacturing, and second life battery screening to name a few.The testing protocol is based on a series of galvanostatic current pulses at a variety of currents and/or times. By utilizing the natural differences in time-constant of the various electrochemical phenomena inside a battery, this technique can probe each mechanism to glean novel insight using standard battery cycling equipment. Specifically, the insights this technique can provide include: the electrochemical potential of each phase during lithiation and delithiation quantification of electrode kinetics at various states-of-charge (including exchange current density estimation from the Butler-Volmer model)quantitative estimation of transport-based polarization losses from both the electrodes and the electrolyte. This analysis provides an un-parallelled level of mechanistic insight into the inner workings of any battery, at any point, spanning small-scale R&D cells to large format cells in mass production.To demonstrate the capabilities of this technique this presentation will focus on the analysis of multiple cells (same model) from a Tier 1 supplier containing a lithium transition metal oxide cathode material cycled at various temperatures. These results have led to an extensive set of conclusions. For brevity a few of these conclusions are: The initial exchange current density of these cells is calculated to be 25.5 A/m2. The H2→H3 phase transition during charging is the least efficient phase, exhibiting the largest power loss during chargingThe inefficiencies in the H2→H3 phase transition are dominated by solid-state lithium atom diffusion within the electrodes. At low current densities the overpotential associated with transport is the dominant source of losses, while at higher currents kinetic overpotentials become the dominant source. In summary, we have developed a novel characterization technique requiring only standard battery cycling equipment that can be easily and quickly performed by researchers around the world. Whether on small-scale coin cells or large-format pouch cells, the analysis from this technique will give the battery community insight into the thermodynamic, kinetic, and transport properties of their system. Moreover, this technique can be applied in a variety of contexts related to battery development, including understanding degradation mechanisms, performing root-cause analysis of manufacturing defects, or providing more accurate parameters for computational modeling.

Operando Electrochemical Liquid Cell STEM Investigation of the Growth and Evolution of the Mosaic Solid Electrolyte Interphase for Lithium-Ion Batteries

The solid electrolyte interphase (SEI) is a key component of a lithium-ion battery forming during the first few dis-/charge cycles at the interface between the anode and the electrolyte. The SEI passivates the anode-electrolyte interface by inhibiting further electrolyte decomposition extending the battery's cycle life. Insights into SEI growth and evolution in terms of structure and composition remain difficult to access. To unravel the formation of the SEI layer during the first cycles, operando electrochemical liquid cell scanning transmission electron microscopy (ec-LC-STEM) is employed to monitor in real time the nanoscale processes that occur at the anode-electrolyte interface in their native electrolyte environment [1]. The results show that the formation of the SEI layer is not a one-step process, but comprises multiple steps. The growth of the SEI is initiated at low potential during the first charge by decomposition of electrolyte leading to the nucleation of inorganic nanoparticles. Thereafter, the growth continues during subsequent cycles by forming an island-like layer. Eventually, a thick dense layer is formed with a mosaic structure composed of larger inorganic patches embedded in a matrix of organic compounds. While the mosaic model for the structure of the SEI is generally accepted, our observations document for the first time how the complex structure of the SEI is built up during dis-/charge cycling.[1] W. Dachraoui, R. Pauer, C. Battaglia, R. Erni, ACS Nano 2023, 17, 20434

Homogenizing Interfacial Stress by Nanoporous Metal Current Collector to Enable Stable All-Solid-State Li Metal Battery

All-solid-state lithium-metal batteries are prone to shorting due to lithium penetration through the electrolyte layer. Li experiences creep during compression which creates stress in the electrolyte layer. Uneven deposition and stripping of Li further exaggerate the heterogeneity of stress distribution. To overcome this challenge, we design a current collector for Li metal. Its specific properties can homogenize interfacial stress distribution and prevent the solid electrolyte layer from developing additional defects that encourage penetration by Li metal during processes of fabrication and electrochemical cycling. Compared with a conventional current collector, our current collector effectively enhances the critical current density (1.7 vs. 0.5 mA/cm2) and extends cycle life (> 360 vs. 12 hours) for Li/Li symmetric cells. This development provides a chemistry-agnostic approach to improving the cycle life of solid-state Li batteries.

Innovative Nanoscale Ceramic Separators to Boost Cycle Life and Cycle Efficiency of Lithium Metal Batteries

In the pursuit of advancing energy storage, the extraordinary theoretical specific capacity of lithium metal at 3,860 mAh/g significantly outperforms traditional graphite anodes, which offer a capacity of around 372 mAh/g. This disparity underscores the potential of lithium metal batteries to facilitate a leap in energy density, heralding a new age of high-performance batteries. Yet, the evolution of lithium metal batteries is hindered by the formation of dendritic structures during repetitive cycling, posing serious risks, including the likelihood of short circuits that underscore severe safety concerns. To mitigate these risks and enhance the longevity of lithium metal anodes, extensive research has been dedicated to various strategies, including surface modifications of lithium metal and the application of innovative coatings on separators. These strategies, however, often compromise energy density and ionic conductivity due to the addition of ceramic materials and binders. Our study introduces a groundbreaking approach that utilizes nanoscale ceramic-coated separators, created via electron beam deposition. This method achieves a consistent nanoscale spread of metal oxide particles on conventional polyethylene (PE) separators. Crucially, this technique ensures even lithium-ion flow and greatly reduces dendrite growth. The effectiveness of this innovative approach was confirmed in comprehensive LiFePO4-Li cell tests, where cells with these ceramic-coated separators showed notable improvements in both cycle life and Coulombic efficiency, representing a significant advancement over traditional methods.

Optimization of Bi2O3 Content in CuO-Bi2O3 Cathodes for Secondary Zn Alkaline Batteries Leads to Improved Capacity and Cycling

Secondary alkaline batteries pairing Zn anodes with metal oxide cathodes (MnO2, CuO, etc.) are a promising route to energy-dense, inexpensive batteries for use in grid-scale energy storage. However, the low cycle life and material stability of secondary alkaline batteries, especially when compared to competing chemistries like Li-ion batteries, must be addressed in order to further develop these technologies. In recent years, studies have shown that the addition of chemical additives like Bi2O3 to the metal oxide cathodes can significantly improve their cyclability. Further work is needed, however, to better understand the mechanism of this improvement and further optimize cathode composition and performance.In this presentation, we will present our efforts to optimize the Bi2O3 composition of a CuO-Bi2O3 cathode for use in secondary Zn-CuO alkaline batteries. Earlier reports showed that relatively large quantities of Bi2O3 additive (10 wt.%) allowed for improved cathode conductivity and promoted the electroreduction of CuOx to Cu0. However, the use of such large quantities of a heavy additive also reduced the effective capacity of the resulting cathode by up to 15%, relative to a CuO cathode without any Bi2O3. Here, we show that the use of as little as 1 wt.% Bi2O3 is sufficient to affect a similar improvement in CuO cycling performance, and that even a Bi2O3-saturated KOH electrolyte solution is sufficient to impact the cyclability of a CuO cathode. Using a variety of physical and (electro)chemical techniques, we show that at these low Bi concentrations the Bi likely cycles between a sparingly soluble BiOx/Bi(OH)4 2- reservoir contained in both the cathode and electrolyte in the charged state, and solid Bi0 that is uniformly distributed on the surface of the CuOx/Cu0 cathode in the discharged state. Various electron microscopy techniques (SEM and STEM) show that this has a notable impact on the physical morphology of the active material in the cathodes after cycling, while electrochemical impedance spectroscopy (EIS) shows how electron transfer resistance varies based on Bi2O3 concentration. On a fundamental level, our results show that changes in Bi2O3 concentration notably impact the charge-discharge behavior of the CuO cathodes and results in the suppression of metal hydroxide-related redox peaks on charge. The absence of these peaks is thus correlated with improved cyclability, suggesting that the addition of Bi and the suppression of these recharge pathways may lead to higher capacity, more stable CuO cathodes in the future.This work was supported by the U.S. Department of Energy, Office of Electricity and Sandia National Laboratories, a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Dr. Imre Gyuk, Director of Energy Storage Research, Office of Electricity is thanked for his financial support. The views expressed herein do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

Noble Dome: A Novel Air-Free Transfer System For Battery Research with Electron Microscopy

"Noble Dome: A Novel Air-Free Transfer System" introduces an innovative solution for loading air-sensitive samples into SEM/FIB instruments. Traditional loading methods expose samples to atmosphere during transfer, hindering investigations of reactive materials. The presented prototype, Noble Dome, directly attaches to the SEM/FIB, enabling sample transfer in an oxygen-free environment. The device's design and operational process are outlined, including airtight chambers, gas introduction, and modified venting systems. Experimental results demonstrate Noble Dome's effectiveness in preserving sample integrity. Compared to existing solutions, which often pose limitations, Noble Dome offers a practical approach for various research needs.Imaging and micromanipulation techniques such as Scanning Electron Microscopy (SEM) and Focused Ion Beam (FIB) can reveal critical information about the microstructure and composition of materials. To utilize these techniques, a sample must be loaded into the chamber of the instrument which is then pumped down to low vacuum conditions. In the process of removing a sample from its packaging and mounting it on the SEM/FIB stage, the sample is briefly exposed to atmosphere. This is problematic for researchers who are interested in investigating air sensitive samples or samples for which atmospheric contamination would detract from the investigation. This set of samples includes metals commonly used as battery materials such as lithium and sodium, which are highly reactive with elements in the air such as moisture or oxygen.We present a prototype for a glove box load lock that addresses this problem directly. This device attaches directly onto the side of a SEM/FIB and allows researchers to remove a sample from packaging and transfer it directly on the stage via an accessory port of the SEM/FIB in an oxygen-free environment and then pump the tool down to vacuum without any atmospheric exposure in the process, eliminating the use of an intermediary shuttle from a separate glove box. We call this device Noble Dome.In order to test Noble Dome’s ability to protect samples from atmosphere, we imaged and collected EDS spectra on the same location of a lithium metal sample in a pristine state, after sitting in Noble Dome for 30 minutes, and after sitting in atmosphere for 30 minutes.We note that there was very little change in the surface topography and oxygen counts between the sample in its pristine state and the sample after sitting in Noble Dome for 30 minutes. However, there is a marked increase in surface oxidation and topography after the sample sat in atmosphere for 30 minutes.Lithium-ion batteries are increasingly prolific in the landscape of modern technology. In order to improve the energy density, life cycle and safety of lithium-ion batteries, researchers require significant amounts of materials characterization pre-assembly, post-assembly and after several charge/discharge cycles. Electron microscopy is crucial for effective materials characterization, which necessitates a solution for loading samples into the vacuum chamber of the microscope without exposing these reactive samples to air.Other solutions currently on the market for loading air sensitive samples into a SEM/FIB involve manipulating the sample in a glove box which is separate from the instrument, loading the sample into an inert gas transfer shuttle which is closed by remote control, removing the shuttle from the glovebox, loading the shuttle into the SEM/FIB, and then opening the sample again via remote control. These solutions are not ideal because they're very expensive, have a variety of limitations on sample size, stage travel, and signal strength, and are high tech solutions prone to costly malfunction. These drawbacks highlight the demand for a more practical and efficient approach.The presented prototype, Noble Dome, addresses the challenge of loading air-sensitive samples into SEM/FIB instruments with a practical and innovative approach. The device eliminates the need for an intermediary glove box and inert gas transfer shuttle, allowing direct sample transfer onto the stage in an oxygen-free environment. The results demonstrate Noble Dome's efficacy in preserving sample integrity by minimizing atmospheric exposure, as evidenced by the minimal changes observed in surface topography and composition compared to samples exposed to atmosphere. Noble Dome enables research on reactive samples, used to pursue a carbon-free future. Figure 1

Electrolytes with Controlled Polysulfide Insolvability for Lithium-Sulfur Batteries

With the rise in manufacturing and commercialization of electric vehicles and home-scale integrated battery systems, low cost and high energy batteries are imperative for meeting the demand of the near-future energy requirements. Lithium-sulfur (Li-S) battery is widely known as a promising candidate for next-generation batteries due to its high theoretical specific energy (2600 Wh kg-1), abundance in material, and potentially low cost. However, there are many challenges unique to Li-S battery chemistries that impede the practical implementation of Li-S batteries. The foremost known challenge is inhibiting the shuttling effect of polysulfide (PS) species, Li2Sn (2 < n ≤ 8) that occurs during the discharge of the elemental S and the charge of the discharged product Li2S on the S cathode. The formed PS species can migrate from the S cathode to the Li metal anode and react with the Li resulting in loss of active materials and insulation of Li anode, and consequently reduced battery performance and cycle life. Managing the mechanism of PS formation and dissolution is paramount to developing a sustainable Li-S battery. Electrolyte formulation is a key strategy in overcoming the hurdles of Li-S batteries and controlling the degree of PS dissolution. Ether-based electrolytes are promising candidates due to their well-known compatibility with Li metal and their varying degrees of PS solvation and dissolution. This work focuses on designing electrolytes that optimizes the degree of PS dissolution and improving electrode-electrolyte compatibility with the elemental S cathode and the Li metal anode to enhance the cell stability and enable long-term cyclability. A series of electrolytes that have a more controlled degree of PS formation and solvability are developed to improve compatibility of the Li-S battery and enable superior cyclability.

Operando Stress Evolution in Hard Carbon Anodes – Insight into the Mechanical Degradation Induced Failure Mode in Rechargeable Sodium Ion Batteries

Microstructural instabilities in electrodes arising from cycling induced stress is a primary failure mode in rechargeable batteries. Therefore, a quantitative knowledge of the cycling induced stress evolution in rechargeable battery electrodes is important for understanding the electrode microstructural instabilities during cycling that can potentially inform the electrode design to prolong battery cycle life. The cycling induced stress in electrodes typically arises from the volume changes associated with insertion/extraction of the electroactive species in the electrode matrix. For example, operando measurement of lithiation-delithiation induced stress in graphite electrodes that typically show 10% volume change has previously resulted in useful information that correlates well with the lithiation-delithiation mechanism in graphite anodes1. The size of the shuttling-electroactive species can be taken as an indicator of the cycling induced stress magnitude that drives the electrode microstructural instabilities. In this regard, quantification of the cycling induced stress in rechargeable Na-ion battery electrodes is warranted for understanding mechanical degradation induced failure modes owing to the larger size of the electroactive species, i.e., Na ions (vs. Li-ion).Hard carbons as potential anodes in rechargeable sodium ion batteries has gained considerable attention in the recent past due to their superior Na-ion storage capability (vs. graphite that is a canonical anode in rechargeable lithium-ion batteries). However, hard carbon anodes typically show significant capacity fade that can potentially arise from cycling induced mechanical degradation of the anodes. Operando stress measurements coupled with comprehensive electrode microstructural characterization will provide valuable insights in this context. Here we report on the operando stress evolution in hard carbon anodes in rechargeable sodium ion batteries as probed by Multiple Optical-beam Sensing (MOS) technique that basically involves monitoring the spacings among a group of laser spot (Fig. 1). Preliminary measurements have shown that the stress correlates with the potential with a maximum around 12 MPa in compression during sodiation and tensile stress of ~ 2MPa during desodiation. Operando stress measurements are performed in hard carbon anodes in two different electrode configurations – typical composite anodes (with binder and conductive agents) and hard carbon thin film anodes (without binder and conductive agents). The thin film configuration is considered to evaluate intrinsic stress response in hard carbon anodes in absence of any secondary phase. A comparison of operando stress response in these two types of hard carbon anodes along with comprehensive electrode microstructural characterization will be presented. Additionally, attempts will be made to shed light on the current debate in the mechanism of sodium storage in hard carbon anodes by comparing operando stress response of hard carbons from multiple sources along with their structural characterization (Raman, XPS, surface area etc.). V. A. Sethuraman, N. Van Winkle, D. P. Abraham, A. F. Bower, and P. R. Guduru, Journal of Power Sources, 206, 334–342 (2012). Figure 1

Voltammetric Study of Phase Separating Anode Materials in Li-Ion Battery Using Phase Field Model

The increasing demand for higher energy capacity in lithium-ion batteries has underscored the significance of modeling lithiation with alternative electrode materials, such as silicon (Si) and tin (Sn). This research addresses the need for comprehensive insights into the (dis)charging process, particularly focusing on the intricate phase transformations in the anode. Phase-field modeling has proven effective in capturing these transformations [2], revealing volumetric deformations of up to 300% during (dis)charging cycles [1]. Unfortunately, these deformations compromise material integrity, leading to reduced battery cycle life and reliability.To address these challenges, our work presents a novel framework for modeling lithiation in materials exhibiting two-phase diffusion using phase field modeling. Unlike previous models limited to single-phase diffusion, our framework provides a more realistic representation of the diffusion process. This realism is achieved by incorporating the time-dependent voltage applied to the anode, a crucial factor in understanding the electrochemical response during lithiation [3].Furthermore, we leverage the currents generated during the lithiation and delithiation processes to conduct a comprehensive voltammetric study. This study goes beyond existing research by considering the impact of phase separation on the currents developed during Li-ion battery operation. Our findings aim to contribute valuable insights into optimizing battery performance and addressing challenges associated with phase transformations, ultimately advancing the development of high-capacity anodes for lithium-ion batteries. REFERENCES [1] McDowell M. T., Lee S. W., Nix W. D., Cui Y. 25th Anniversary Article: Understanding the Lithiation of Silicon and Other Alloying Anodes for Lithium-Ion Batteries. Adv. Mater., Vol. 25 (36), pp. 4966–4985, 2013.[2] Chen L., Fan F., Hong L., Chen J., Ji Y. Z., Zhang S. L., Zhu T., Chen L. Q. A Phase-Field Model Coupled with Large Elasto-Plastic Deformation: Application to Lithiated Silicon Electrodes. J. Electrochem. Soc., Vol. 161 (11), pp. F3164–F3172, 2014.[3] Swaminathan, N., Balakrishnan, S., & George, K. Elasticity and Size Effects on the Electrochemical Response of a Graphite, Li-Ion Battery Electrode Particle. Journal of The Electrochemical Society, 163(3), A488–A498, 2016. Figure 1

Performance Analysis of Multiple Energy-Storage Devices Used in Electric Vehicles

Considering environmental concerns, electric vehicles (EVs) are gaining popularity over conventional internal combustion (IC) engine-based vehicles. Hybrid energy-storage systems (HESSs), comprising a combination of batteries and supercapacitors (SCs), are increasingly utilized in EVs. Such HESS-equipped EVs typically outperform standard electric vehicles. However, the effective management of power sources to meet varying power demands remains a major challenge in the hybrid electric vehicles. This study presents the development of a MATLAB Simulink model for a hybrid energy-storage system aimed at alleviating the load on batteries during periods of high power demand. Two parallel combinations are investigated: one integrating the battery with a supercapacitor and the other with a photovoltaic (PV) system. These configurations address challenges encountered in EVs, such as power fluctuations and battery longevity issues. Although batteries are commonly used in conjunction with solar PV systems for energy storage, they incur higher operating costs due to the necessity of converters. The findings suggest that the proposed supercapacitor–battery configuration reduces battery peak power consumption by up to 39%. Consequently, the supercapacitor–battery HESS emerges as a superior option, possibly prolonging battery cycle life by mitigating stress induced by fluctuating power exchanges during the charging and discharging phases.

A novel hybrid electrochemical equivalent circuit model for online battery management systems

Accurate battery modeling and parameter identification play pivotal roles in ensuring safety and reliability across the entire battery life cycle. Equivalent circuit models (ECM) are convenient but do not represent physical characteristics well; in contrast, electrochemical models with strong physical meaning are hard to parameterizing in an online setting. To address these challenges, this paper introduces a novel hybrid electrochemical Equivalent Circuit Model (eECM), which integrates electrochemical processes into an ECM, representing slow-dynamic internal processes with a simplified representation of solid- and liquid-phase diffusion; fast-dynamics are represented by ECM terms. The model is supported by an Adaptive Extended Kalman Filter (AEKF) to manage battery state changes and mitigate noise. To enhance parameter identification, a Fisher information matrix-enhanced Variable Forgetting Factor Recursive Least Squares (Fisher-VFFRLS) approach is employed, guided by the Cramér–Rao bound for identifying the most sensitive data points directly from the discharge cycle. Electrochemical parameters are determined via post-charging rest via a Genetic Algorithm (GA). The proposed methodology is validated on three dynamic cycles—DST, US06, and FUDS-demonstrates the effectiveness of the proposed eECM and parameter identification strategy, with maximum Root Mean Square Error (RMSE) for terminal voltage and State of Charge (SoC) estimation below 0.0076 and 0.0122, respectively.

Sustainable Battery Lifecycle: Non-Destructive Separation of Batteries and Potential Second Life Applications

Large quantities of battery systems will be discarded from electric vehicles in the future. Non-destructive separation of used electric vehicle (EV) traction batteries enables a second life of battery components, extraction of high value secondary materials, and reduces the environmental footprint of recycling and separation processes. In this study, the key performance indicators (KPIs) for the second life application of spent EV batteries are identified. Three battery packs are analyzed in terms of the joining techniques used—and possible separation techniques—considering only direct recycling methods. The components that can be recovered from these batteries are evaluated against the KPIs. This study shows that all the batteries analyzed allow a second life in stationary and semi-stationary electrical storage systems and marine applications when used at the pack and module levels. Two packs can be reused in electric vehicles such as forklifts. However, the feasibility of re-use in micro-mobility and consumer electronics is very limited. This study shows that technically feasible separation methods are dictated and constrained by the joining techniques used. As welding and adhesive bonding pose challenges to separation processes, future efforts should prioritize ‘design for disassembly’ to ensure sustainable battery life cycle management.

PH modulation for high capacity and long cycle life of aqueous zinc-ion batteries with β-MnO2/3D graphene-carbon nanotube hybrids as cathode

pH modulation for high capacity and long cycle life of aqueous zinc-ion batteries with β-MnO2/3D graphene-carbon nanotube hybrids as cathode

Remaining useful life prediction of Lithium-ion batteries using spatio-temporal multimodal attention networks

Lithium-ion batteries are widely used in various applications, including electric vehicles and renewable energy storage. The prediction of the remaining useful life (RUL) of batteries is crucial for ensuring reliable and efficient operation, as well as reducing maintenance costs. However, determining the life cycle of batteries in real-world scenarios is challenging, and existing methods have limitations in predicting the number of cycles iteratively. In addition, existing works often oversimplify the datasets, neglecting important features of the batteries such as temperature, internal resistance, and material type. To address these limitations, this paper proposes a two-stage RUL prediction scheme for Lithium-ion batteries using a spatio-temporal multimodal attention network (ST-MAN). The proposed ST-MAN is to capture the complex spatio-temporal dependencies in the battery data, including the features that are often neglected in existing works. Despite operating without prior knowledge of end-of-life (EOL) events, our method consistently achieves lower error rates, boasting mean absolute error (MAE) and mean square error (MSE) of 0.0275 and 0.0014, respectively, compared to existing convolutional neural networks (CNN) and long short-term memory (LSTM)-based methods. The proposed method has the potential to improve the reliability and efficiency of battery operations and is applicable in various industries.

Improvement of rate capability and cycle life of Na-NiCl2 battery via designing a graphene anchoring porous nickel nanostructures as cathode

The integration of renewable energy with advanced energy storage technologies is essential. The sodium-based batteries, particularly sodium-nickel chloride (Na-NiCl2) batteries, show promise due to the abundance and low redox potential of sodium (−2.7 V vs. SHE). Despite their advantages in terms of cost, safety, and high efficiency, the improvement of rate and cycling performance of Na-NiCl2 batteries remains a challenge. To address this issue, a Ni nanostructure-supported reduced graphene oxide (RGO) composite is synthesized and combined with NaCl to serve as the cathode material for Na-NiCl2 batteries. Benefiting from the strong anchoring function of RGO, the growth of Ni is inhibited. As a result, the obtained cathode exhibits a notable specific capacity of 132.7 mAh/g at a high rate of 0.6C, along with excellent Coulombic efficiency of 100 % over 500 cycles and high energy efficiency (95.8 %). In addition, the outstanding conductivity, high specific surface area and abundant pore distribution of Ni@RGO contribute to enhanced conversion reaction and ion diffusion, and thus promoting rate capability. In contrast, the pure Ni nanosheets-based (Ni NSs) cathode is subjected to serious grain growth, which leads to poor rate performance and rapid capacity fading. By introducing conductive framework of RGO and constructing porous Ni nanostructure, the rapid electrons transport and diffusion of ions is achieved, and thus presenting the exceptional electrochemical properties.

Carbon emission assessment of lithium iron phosphate batteries throughout lifecycle under communication base station in China

The demand for lithium-ion batteries has been rapidly increasing with the development of new energy vehicles. The cascaded utilization of lithium iron phosphate (LFP) batteries in communication base stations can help avoid the severe safety and environmental risks associated with battery retirement. This study conducts a comparative assessment of the environmental impact of new and cascaded LFP batteries applied in communication base stations using a life cycle assessment method. It analyzes the influence of battery costs and power structure on carbon emissions reduction. Results indicate: When consuming the same amount of electricity in a cascaded battery system (CBS), LFP batteries with a retirement state of health (SOH) range between 76.5 % and 90.0 % can reduce 30.3 % of the global warming potential (GWP) compared to new batteries. From the perspective of battery costs, when the price ratio of new to old batteries is greater than 31.0 %, the GWP of batteries retired at 70.0 % SOH is higher than that of new batteries. As the proportion of renewable energy sources in the power structure increases, the GWP of new batteries in 2035 is 15.0 % lower than in 2020. For batteries retired at 80.0 % SOH, their GWP decreases by 12.3 % compared to 2020. This study offers a new approach to determining the retirement point for LFP batteries from an environmental perspective, promoting carbon emission reduction throughout the entire battery life cycle and the sustainable development of the transportation sector.

Sulphur/functionalized graphene composite as cathode for improved performance and life cycle of lithium-sulphur batteries

Over the past years, significant advantages have been introduced to upgrade the performance of lithium-sulfur battery (Li-S) batteries since their prototype in the 1960s. Due to high theoretical energy density and cost efficiency, Li-S batteries have obtained great attention and have made great progress in the last few years. In this work, we developed the sulfur-attached few-layer graphene composite (S/FLG), sulfur-attached functionalized few-layer graphene using acetic acid (S/FLG-COOH) and sulfur-attached functionalized few-layer graphene using strong acid H2SO4 and HNO3 (S/FLG-OH) as a cathode material with high sulfur loading. The material’s structure is confirmed through XRD. The surface morphology is confirmed through SEM and elemental composition has been obtained through EDAX. The functional groups are confirmed through FTIR. The defect level and number of layers are confirmed through Raman characterization with an excitation laser wavelength of 532 nm. The electrochemical performance of three cathodes is also identified through EIS, CV, and GCD characterization. Meanwhile, highly developed defects and edges found in the functionalization of few-layer graphene using the strong acid (H2SO4 and HNO3) which consists of a hydroxyl functional group (FLG-OH) serve as polysulfide reservoirs to mitigate the shuttle effect. Among these cathodes, S/FLG-OH shows a high specific capacitance of 157.4 F g−1 and when applied as a cathode host on a coin cell it obtained a voltage of about 2.6 V. Well-performed S/FLG-OH cathode was used to fabricate the Coin Cell. The fabricated Coin Cell with S/FLG-OH as the cathode shows a stable potential over 50 cycles.

In Situ Characterization of Metastable Pb3O5 and Pb2O3 Phases During Thermal Decomposition of PbO2 to PbO.

Nonstoichiometric lead oxides play a key role in the formation and cycling of the positive electrodes in a lead acid battery. These phases have been linked to the underutilization of the positive active material but also play a key role in the battery's cycle life, providing interparticle adhesion and the connection to the underlying lead grid. Similar phases have previously been identified by mass loss or color change during thermal annealing of PbO2 to PbO, suggesting that at least two intermediate PbOx phases exist. Using multiple, in situ analysis techniques (powder diffraction, X-ray absorption, X-ray photoelectron spectroscopy) and ex situ nuclear magnetic resonance measurements, the structural conversion and changes in the lead oxidation state were identified during this process. Isolation of the PbOx phases enabled confirmation of Pb3O5 and Pb2O3 by diffraction and the first 207Pb NMR measurement of these intermediates. The thermodynamic and kinetic stability of these intermediates and other reported polymorphs were determined by density functional theory, providing key insight into their origins and variation of PbOx structures found in previous studies.

The Possible Mechanism of Improving the Performance of Lead‐Acid Batteries by Using Aluminum Ions to Influence the Gel Structure

Gel lead‐acid batteries have the advantages of no acid leakage, no maintenance, and a long cycle life. In this article, it was found that Al3+ in the gel electrolyte can shorten the gel time and improve the stability of the gel. The battery test results show that the HRPSoC cycle life of the gel battery can be significantly improved by adding Al3+. In comparison to blank gel batteries without Al3+, HRPSoC cycle life is 8.2 times higher. Additionally, the gel battery with added Al3+ has a 0.5C discharge capacity of 1.8 Ah, which is 2.5 times that of the blank gel battery. The added Al3+ also demonstrates good capacity stability and still retains a capacity of 1.7 Ah after 150 discharge cycles. The kinetic simulation shows that Al3+ may participate in the formation of a silicon gel system and tend to gather around Si atoms to affect the properties of the gel electrolyte.