batterydata/paper-abstracts huggingface dataset:
Flexible electrode material with high mechanical strength and excellent electrical stability is still a great challenge for the fabrication of highly flexible energy storage devices. Commercial carbon cloth has been long reported as flexible substrate for many electrode materials due to their high mechanical strength and flexibility. However, their application directly as electrode material for flexible lithium ion batteries is yet to be reported. In this paper, commercial carbon cloth was thermally etched and used directly as electrode material in the half-cell and all-flexible full lithium ion batteries. Upon the mass weight and the large diameter of the carbon fiber, the as-prepared free-standing N-doped Porous carbon cloth delivered an initial capacity of 1.75mAh/cm2 (190mAh/g) and capacity up to 1.65mAh/cm2 (168mAh/g) after long electrochemical cycles in the half-cell. The all-flexible device exhibits a high working potential of 3.4V, remarkable lithium storage performance and excellent flexibility. It also achieves a maximum volumetric energy density of 43Wh/cm3 at 0.125mA/cm2 and power density 800W/cm3 at 5.0mA/cm2 . The excellent performance can be attributed to N-doped porous surfaces, which provide large surface area for more lithium storage.
In this work, we have successfully grown single-crystalline nanoneedle arrays of NiCo2O4 on conductive substrates such as Ni foam and Ti foil through a simple solution method together with a post-annealing treatment. Remarkably, the NiCo2O4–Ni foam binder-free electrode exhibits greatly improved electrochemical performance with very high capacitance and excellent cycling stability.
An essential key to enhance the redox chemistry of battery-type materials is to construct rational design of nanoarchitectures with high electrochemical activity. Herein, we reported a hierarchical composite consisting of bilayered nickel hydroxide carbonate nanoplates-decorated nanoflowers on nickel foam (NHC NPs@NFs/Ni foam) via a facile homogeneous precipitation method for use as an effective cathode in hybrid supercapacitors (HSCs). Under controlled growth time (4 h), the bilayered NHC NPs@NFs with hierarchical alignment were spontaneously crystallized on Ni foam. The as-preapared hybrid structure greatly enhanced the electroactive surface area and enabled the rapid redox chemistry in alkaline electrolyte. Notably, the hybrid NHC NPs@NFs/Ni foam delivered a maximum areal capacity of 727.4 μAh/cm2 at 2 mA/cm2 and it is relatively higher than its oxide form (76.6 μAh/cm2) in a three-electrode system. Also, a pouch-type HSC with bilayered NHC NPs@NFs/Ni foam and porous carbon electrodes was fabricated, which demonstrated superior energy storage performance in terms of capacitance (1445.8 mF/cm2), energy density (0.506 mWh/cm2), power density (35.675 mW/cm2) and cycling stability (89.4%). Furthermore, the self-charging power station consisting of a solar cell for energy conversion and the HSCs for energy storage was also assembled to operate the portable electronic displays and wall clock effectively for long time. This facile approach for the cost-effective fabrication of hierarchically designed nanomaterials paves a path for the development of high-performance hybrid supercapacitors.
The gelation of commercial lithium iron phosphate (LiFePO4) in water-based slurry and its corresponding mechanism are studied. When a large portion of the inner LiFePO4 of commercial carbon-coated LiFePO4 is exposed, the powder becomes polar and its surface possesses numerous hydroxyl groups that tend to form a three-dimensional gel-like structure via hydrogen bonding.
Improving the low-temperature tolerance and increasing the energy density of supercapacitors are currently desirable for real-life applications. Commercially available non-aqueous supercapacitors are typically limited in operation to −40 °C or higher, and they usually exhibit poor performance at lower than room temperature. In this work, we investigate symmetric supercapacitors using the 1-butyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) ionic liquid modified with organic solvents as the electrolyte and activated polyaniline-derived carbon (APDC) as the active material. The symmetric coin cells tests are performed in the range of temperatures from −100 °C to 25 °C. Interestingly, with decreasing temperature, the working voltage window of these supercapacitors gradually increases from 2.5 V to 4.0 V, whereas the energy density initially increases and then decreases. The optimal combination of an APDC electrode and the EMIMBF4/acetonitrile/methyl acetate-based electrolyte enables such a supercapacitor to work with a high potential window of 3.5 V and deliver a maximum energy density of 80 Wh kg−1 (based on the total mass of the two-electrode material), a maximum power density of 26 kW kg−1, and a long-term cycle life of 10000 cycles at a low temperature of −50 °C.
It has remained a challenge to develop a facile and scalable approach to synthesize high-energy lithium-ion battery (LIB) electrode materials with excellent rate capabilities and prominent cycling stabilities for their applications in new generation energy storage devices. In this study, for the first time, we report a crumpled reduced graphene oxide (cG) encapsulated three-dimensional (3D) hollow vanadium pentoxide (V2O5) nano/microspheres fabricated by one-step solvothermal treatment followed by subsequent annealing. This rapid and effective synthesis method is environmental friendly and economically beneficial without involving costly organic vanadium sources, tedious operation, or sophisticated equipment. Remarkably, the desired cG-encapsulated V2O5 composite contains 5wt% reduced graphene oxide (rGO), yet exhibits outstanding rate capacities and cycling stabilities. This product can deliver reversible capacities of 289mAhg−1 at 100mAg−1 and 163mAhg−1 at 5000mAg−1 (492Whkg−1 and 9840Wkg−1), as well as a capacity retention of about 94% after 200 cycles at 2000mAg−1 in the potential range between 2.0V and 4.0V (vs. Li/Li+). Furthermore, the unique structural feature and typical formation mechanism of the designed materials are clarified based on multiple experimental results. More commendably, a chain of solid powders had been successfully encapsulated using this scalable reaction system. It is expected that this versatile approach will facilitate the applications of cG, and provide a novel avenue to create more fascinating rGO-based functional materials.
A regional telemedicine hub, providing linkage of a telemedicine command center with an extended network of clinical experts in the setting of a natural or intentional disaster, may facilitate future disaster response and improve patient outcomes. However, the health benefits derived from the use of telemedicine in disaster response have not been quantitatively analyzed. In this paper, we present a general model of the application of telemedicine to disaster response and evaluate a concept of operations for a regional telemedicine hub, which would create distributed surge capacity using regional telemedicine networks connecting available healthcare and telemedicine infrastructures to external expertise. Specifically, we investigate (1) the scope of potential use of telemedicine in disaster response; (2) the operational characteristics of a regional telemedicine hub using a new discrete-event simulation model of an earthquake scenario; and (3) the benefit that the affected population may gain from a coordinated regional telemedicine network.
Accurate state of charge (SOC) estimation is very crucial to guarantee the safety and reliability of lithium-ion batteries, especially for those used in electric vehicles. Since the SOC is unmeasurable and nonlinearly varies with factors (e.g., current rate, battery degeneration, ambient temperature and measurement noise), a reliable and robust algorithm for SOC estimation is expected. In this paper, an optimal adaptive gain nonlinear observer (OAGNO) for SOC estimation is proposed. The particle swarm optimization (PSO) algorithm is employed to optimize parameters of the adaptive gain nonlinear observer (AGNO). A combined error is presented as the fitness function to evaluate the search performance of the PSO algorithm. To perform the PSO-based parameter optimization of the AGNO, a combined dynamic loading profile consisting of the Federal Urban Driving Schedule, the New European Driving Cycle and the Dynamic Stress Test is developed. The proposed approach is verified by experiments performed on Panasonic NCR18650PF lithium-ion batteries and compared with different parametric AGNOs. Experimental results indicate that the proposed OAGNO is helpful to improve the accuracy of battery SOC estimation compared with the non-optimal AGNO methods. Additionally, the OAGNO approach is robust against initial SOC error, current noise and different driving cycles.
An electrochemical study of Li insertion in the αII, γ and δ forms of VOPO4 and the optimization of their cycling performance are presented. The potentials of the intercalation–deintercalation processes and the specific capacities upon discharge have been correlated to the crystal structures of these phases. It is evidenced that the obtained capacities can be improved up to eight times by optimizing the synthesis route or the carbon/active material contact.
Rate capability of LiNi0.8Co0.15Al0.05O2 in solid-state cells was investigated with 70Li2S-30P2S5 glass-ceramics as a sulfide solid electrolyte. It showed higher rate capability than LiCoO2; discharge capacity observed at a current density of 10mAcm−2 was ca. 70mAhg−1. Surface coating with Li4Ti5O12 onto the LiNi0.8Co0.15Al0.05O2 particles further improved the high-rate performance to give ca. 110mAhg−1. The rate capability promises to realize all-solid-state lithium secondary batteries with very high performance.
Bycatch in fisheries can have profound effects on the abundance of species with relatively low resilience to increased mortality, can alter the evolutionary characteristics and concomitant fitness of affected populations through heritable trait-based selective removals, and can alter ecosystem functions, structure and services through food web trophic links. We challenge current piecemeal bycatch management paradigms, which reduce the mortality of one taxon of conservation concern at the unintended expense of others. Bycatch mitigation measures may also reduce intraspecific genetic diversity. We drew examples of broadly prescribed ‘best practice’ methods to mitigate bycatch that result in unintended cross-taxa conflicts from pelagic longline, tuna purse seine, gillnet and trawl fisheries. We identified priority improvements in data quality and in understanding ecological effects of bycatch fishing mortality to support holistic ecological risk assessments of the effects of bycatch removals conducted through semi-quantitative and model-based approaches. A transition to integrated bycatch assessment and management that comprehensively consider biodiversity across its hierarchical manifestations is needed, where relative risks and conflicts from alternative bycatch management measures are evaluated and accounted for in fisheries decision-making processes. This would enable managers to select measures with intentional and acceptable tradeoffs to best meet objectives, when conflicts are unavoidable.
The rechargeable lithium–air battery has the highest theoretical specific energy of any rechargeable battery and could transform energy storage if a practical device could be realized. At the fundamental level, little was known about the reactions and processes that take place in the battery, representing a significant barrier to progress. Here, we review recent advances in understanding the chemistry and electrochemistry that govern the operation of the lithium–air battery, especially the reactions at the cathode. The mechanisms of O2 reduction to Li2O2 on discharge and the reverse process on charge are discussed in detail, as are their consequences for the rate and capacity of the battery. The various parasitic reactions involving the cathode and electrolyte during discharge and charge are also considered. We also provide views on understanding the stability of the cathode and electrolyte and examine design principles for better lithium–air batteries.
Solar and wind power based hybrid energy system with energy storage unit provides a reliable and cost effective energy alternative above the conventional diesel generator based system commonly used by remote consumers. In this context, this paper explores the application of a new meta-heuristic algorithm called Cuckoo Search (CS) in the area of a hybrid energy system design problem. Cuckoo Search (CS) is applied for optimal sizing of three different system schemes viz. Photovoltaic-Battery, Wind-Battery and Photovoltaic-Wind-Battery system applicable to a remote area located in Almora district of Uttarakhand, India while minimizing total system cost and considering seasonal variation of load. The effectiveness of Cuckoo Search algorithm in solving hybrid energy system design problem is investigated and its performance is compared with other well known optimization algorithms like Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) algorithm. Optimization results further, shows that hybrid integration of photovoltaic, wind and battery storage gives most reliable and economical system scheme for the study area. In addition, this paper assesses the effect of wind turbine generator (WTG) force outage rate (FOR) on the optimal system reliability and economics.
Different compositions of a ternary solid polymer electrolyte (SPE) system consisting solely of poly(ethylene oxide), lithium bis(trifluoromethansulfonyl)imide (LiTFSI) and the ionic liquid N-methyl-N-butyl-pyrrolidinium bis(trifluoromethane-sulfonyl) imide (Pyr14TFSI) were tested. Differential scanning calorimetry shows that a few ternary polymer electrolytes with selected salt and ionic liquid contents are amorphous at room temperature. The Li+ coordination in the ternary electrolytes was analyzed by Raman spectroscopy while the Li+ transport properties were investigated by means of pulsed-field-gradient NMR (PFG-NMR), impedance spectroscopy and DC methods.
A detailed review is carried out on current micropower technology. In particular, a prototype micropower device based on the concept of a thermophotovoltaic (TPV) system of generating electricity is reviewed in this report. This prototype micro-TPV power generator [W.M. Yang, S.K. Chou, C. Shu, H. Xue, Z.W. Li, J. Phys. D: Appl. Phys. 37 (2004) 1017–1020] is currently under research and development by the National University of Singapore (NUS). Focus is made on the possible improvements to the micro-TPV power device, in particular the efficiency of the micro-combustor, PV cells, and consequently the overall the efficiency.
In the current study, a novel needleless electro-spinneret based on the Von Koch curve of Fractal Theory is developed to prepare electrospun membrane. A sandwich-like composite separator is elaborately designed with two layers of SiO2 nanoparticles doped polyimide membranes being the sheath layers and a single layer of ethylcellulose modified PE membrane being core layer towards its application for separators in high-performance lithium-ion batteries. This tri-layered composite separator combines both thermal shutdown function at low temperature and thermal runaway function at high temperature, where ethylcellulose is used to enhance the interfacial affinity and strength between commercial polyethylene separator and the electrospun polyimide membrane. The two sheath layers of electrospun membrane prepared by SiO2 nanoparticles doped polyimide impart the separator with high thermal stability and high-temperature runaway function at, and the single core layer of ethylcellulose modified polyethylene membrane provides high mechanical property and low-temperature shutdown function. The resultant tri-layered composite membrane is of high potential as lithium-ion battery separators for electrically powered vehicles.
Aquoeus zinc-ion batteries have become an interesting alternative to the traditional technologies used for energy storage from renewable energy sources. Among them, systems based on Prussian Blue derivates have attracted great attention due to their high discharge potential, good cyclability and rate capability. In this work we have observed that both anion and co-cations are playing a critical role in the cycle stability of copper hexacynoferrate. By using post-mortem X-ray diffraction, it is observed that a partial transformation of copper hexacyanoferrate structure occurs via substitution of the transition metals in the lattice. The phase transformation mitigate the energy losses, and in certain conditions allows retaining up to 82% of the initial energy provided after 500 cycles.
A conventional lead acid cell that is exposed to a high rate partial state of charge capacity cycling (HRPSoCCC) would show the results of irreversible negative electrode damage due to excessive PbSO4 formation that can be visually seen by the “Venetian Blinds” effect of the active material. This displays the loss of adhesion of the active material with the electrode's grids thereby making large sections of the material ineffective and reducing the cells useful capacity during high current applications. The use of a commercial lightweight polyester non-woven material that was referred to as “Polymat” was placed on both sides of the negative electrode, has demonstrated a better physical adhesion of the active material thereby maintaining the active material's physical integrity. This however does not reduce the sulphation effect due to the HRPSoCCC test but only reduces the physical damage due to the irreversible active material “Venetian Blinds” effect. The study looked at the effect the Polymat has on the battery's cold cranking ability (CCA) at −18°C, the HRPSoCCC and its active material utilization. Typical flooded nominal 8Ah test cells were assembled with 3 positive and 2 negative plates with and without Polymat. The study showed that there was little or no difference of cells made with the Polymat on the CCA and HRPSoCCC capabilities when compared to cells without the Polymat, with significant improvement in active material's adhesion and integrity to the grid wire. Partial recovery of the cell's discharge capacity made with the Polymat could be achieved after the “failed” cells were subjected to a simple pulse recharge sequence.
Poly(vinylidene fluoride-hexafluoroprolene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with organic-inorganic hybrid particles poly(methyl methacrylate)ZrO2 (PMMA-ZrO2) are fabricated by phase inversion, in which PMMA is firstly successfully grafted onto the surface of the homemade nano-ZrO2 particles via in situ polymerization confirmed by FT-IR. XRD and DSC patterns show that adding PMMA-ZrO2 into the polymer matrix can decrease the crystallinity of the CPE membranes and TG curves indicate the CPE membranes possess desirable thermal stability. It can be found that the CPE membrane presents a uniform surface with abundant interconnected micro-pores when the added amount of PMMA-ZrO2 increases to 5 wt % vs. polymer matrix, in which the ionic conductivity at room temperature and tensile strength can be up to 3.595 mS cm−1 and 26.18 MPa, respectively. In particular, the CPE membrane shows the minimum deformation of about 8% after being exposed at 160 °C for 1 h, and the electrochemical working window of the assembled Li/CPE/SS cell can be stable at 5.1 V (vs Li/Li+) at room temperature. Moreover, the LiCoO2/CPE/Li coin cell can deliver a specific capacity of 114.5 mAh g−1 with 79.13% capacity retention at 2.0 C after 110 cycles. The results suggest that the as-fabricated P(VDF-HFP)-based CPE doped with 5 wt % organic-inorganic hybrid particles PMMA-ZrO2 can be a promising polymer electrolyte for lithium ion batteries.
In order to combine the advantages of core-shell and concentration-gradient Li[Ni1-xMx]O2 materials, a novel structured Li[Ni0.66Co0.1Mn0.24]O2 (NSLi[Ni0.66Co0.1Mn0.24]O2) cathode material is facilely synthesized from core-shell precursor [(Ni0.8Co0.1Mn0.1)0.6(Ni0.45Co0.1Mn0.45)0.4](OH)2 via ion diffusion during high temperature calcination. NSLi[Ni0.66Co0.1Mn0.24]O2 is constructed by core layer, concentration-gradient layer and shell layer. From the detailed comparative investigations, it is found that NSLi[Ni0.66Co0.1Mn0.24]O2 delivers remarkably improved cycle life and thermal stability compared with normal Li[Ni0.66Co0.1Mn0.24]O2 (NLi[Ni0.66Co0.1Mn0.24]O2).
57Fe Mössbauer spectroscopy is particularly useful in the study of oxide and oxalate conversion anode materials for Li-ion batteries. After reduction in lithium test cells, all these materials showed Mössbauer spectra ascribable to iron atoms in two different environments with superparamagnetic relaxation. The spectra recorded at 12 K revealed the ferromagnetic character in agreement with particle sizes of ca. 5 nm. The two types of iron can be ascribed then to surface and core atoms. Core iron atoms play an important role to retain high faradic capacity values for a large number of cycles. These atoms are preserved from irreversible reactions with the electrolyte and hence they promote a high reversibility and rate capability.
The shutdown function of a separator is an important factor in the safety of advanced lithium-ion batteries (ALB). When a separator without proper shutdown function is used, battery safety would depend on the thermal stability of electrode materials. Results show that thermal stability of a battery, contributed from both the anode and cathode, decreases noticeably after cycling. DSC shows that exothermicity from SEI decomposition and the reaction of the lithiated graphite and electrolyte around 140°C increases as cycle number increase; main reason is the gradual thickening of passivation film, observed through three-electrode ac impedance measurements. DSC also shows a similar trend of exothermicity for Li x CoO2 cathode. The lesser the amount of lithium (x-value) in Li x CoO2, the larger the exothermicity and the lower the decomposition temperature. Using a three-electrode system to observe the changes of open-circuit potential in Li x CoO2 cathode, thermal instability is a consequence of decreased lithium content as cycle increases.