Designing Advanced In Situ Electrode/Electrolyte Interphases for Wide Temperature Operation of 4.5 V Li||LiCoO 2 Batteries
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Ether-based electrolytes are considered as promising candidates for sodium-ion batteries (SIBs) due to their high ionic conductivity and good compatibility with hard carbon (HC) anode. However, they suffer from poor anti-oxidative ability with unstable cathode electrolyte interface, inducing successive electrolyte decomposition and rapid capacity fading. Herein, the sulfur-containing additive (1,3-propanediol cyclic sulfate, PCS) is introduced to boost the stability of the electrode-electrolyte interface (EEI) in ether-based electrolyte. PCS largely participates in the inner Na + sheath, causing more diglyme (G2) molecules and fewer PF 6 - anions to occupy the inner Na + solvation sheath, avoiding the decomposition of G2 molecules at high operation voltage. Moreover, PCS is beneficial for simultaneously constructing thin and robust sulfur-containing EEI on both Prussian blue (PB) cathode and HC anode, maintaining the structural stability of PB and alleviating the dissolution of transition metals. These enable PB||HC pouch cells to deliver a capacity retention of 60.3% after 400 cycles, significantly higher than the 32.1% in PCS-free electrolytes. In conclusion, this work discloses the underlying mechanism of PCS to evoke the anti-oxidation ability of ether-based electrolyte and provides a promising method for realizing advanced sodium-ion full cells.
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Provided are electrochemical secondary cells that exhibit excellent abuse tolerance, deep discharge and overcharge conditions including at extreme temperatures and remain robust and possess excellent performance. Cells as provided herein include: a cathode a polycrystalline cathode electrochemically active material including the formula Li1+xMO2+y, wherein −0.9≤x≤0.3, −0.3≤y≤0.3, and wherein M includes Ni at 80 atomic percent or higher relative to total M, the cathode electrochemically active material comprising a non-uniform distribution of Co; an anode including an anode electrochemically active material of the formula Li4+aTi5O12+b wherein −0.3≤a≤3.3, −0.3≤b≤0.3; and wherein the anode and the cathode each independently include a current collector substrate comprising aluminium.
An electrochemical device includes an anode, a separator, a cathode comprising a selenium-doped sulfur/carbon composite that includes a conductive carbon matrix and nano-sized selenium-doped sulfur particles of formula SxSey, where a ratio of x:y is from 2.5 to 1000, and an electrolyte comprising a salt and a non-aqueous fluorinated ether solvent.
It is imperative to recover lead (Pb) contained in end-of-life solar modules. In this paper, a two-step leaching and electrowinning process using acetic acid is investigated for Pb recovery. Acetic acid with hydrogen peroxide can dissolve Pb quickly and, under some conditions, in a matter of minutes. Pb electrowinning has been successfully demonstrated from aqueous solutions of 0.009 M lead(II) acetate with 0–10% v/v acetic acid. Pb-containing deposits are found on both the copper cathode and graphite anode. X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy confirm the presence of metallic Pb and Pb(II) oxide (PbO) co-deposits on the cathode. Further, there is also the formation of lead subacetate on the cathode under certain conditions. On the anode, the deposit consists of lead(IV) oxide and superoxide (PbO 2 and Pb 1–x O 2 ). A Pb recovery rate of 99% is achieved in 0.009 M lead(II) acetate solutions with 10% v/v acetic acid by applying a reduction potential of either –0.8 V or –1.0 V versus the silver/silver chloride reference electrode for 24h. Pb leaching with acetic acid is also demonstrated from milled silicon solar modules.
A method of making a passively impact resistant battery includes the steps of providing a porous separator material having pores and a surface, and providing a suspension composition including shear thickening enabling particles and a particle suspension solvent for suspending the shear thickening enabling particles. The shear thickening particles have a polydispersity index of no greater than 0.1, an average particle size of in a range of 50 nm to 1 um, and an absolute zeta potential of greater than ±40 mV. The suspension composition is applied to the separator material, wherein a portion of the particles and suspension solvent penetrate the pores. The suspension solvent is evaporated from the separator material. An anode layer and a cathode layer are applied. An electrolyte composition is applied between the anode layer and the cathode layer. The electrolyte composition includes an electrolyte solvent and an electrolyte salt.
Nanoparticles decorated electrodes (NDEs) are useful in fuel cells, electrolyzers, water treatment, and chemical synthesis. Here, in this study, we show that by rapidly bringing a mixed ionic-electronic conductor outside its electrochemical stability window, one can achieve uniform dispersion of metallic nanoparticles inside its bulk and at the surface and improve its electrocatalytic performance when back under normal functional conditions. Surprisingly, this can happen under anodic as well as cathodic current/voltage shocks in an ABO 3 perovskite oxide, La 0.4 Ca 0.4 Ti 0.88 Fe 0.06 Ni 0.06 O 3-δ (LCTFN), across a wide range of H 2 /O 2 gas environments at 800 °C. One possible mechanism for bulk Fe 0 /Ni 0 precipitation under anodic shock condition is the incomplete oxygen oxidation (O 2 – → O α– , 0 < α < 2), migration and escape of oxygen to interfaces, and “whiplash” transition-metal reduction due to low electronic conductivity. We show that both cathodic and anodic shocks can produce NDEs to enhance electrocatalytic performance, potentially improving the flexibility of this approach in practical devices.
Reduction-oxidation (redox) reactions that transfer conduction electrons from the anode to the cathode are the fundamental processes responsible for generating power in Li-ion batteries. Electronic and microstructural features of the cathode material are controlled by the nature of the redox orbitals and how they respond to Li intercalation. Thus, redox orbitals play a key role in performance of the battery and its degradation with cycling. We unravel spectroscopic descriptors that can be used to gain an atomic-scale handle on the redox mechanisms underlying Li-ion batteries. Our focus is on X-ray Compton Scattering and Positron Annihilation spectroscopies and the related computational approaches for the purpose of identifying orbitals involved in electrochemical transformations in the cathode. This review provides insight into the workings of lithium-ion batteries and opens a pathway for rational design of next-generation battery materials.
A method of manufacturing an electrochemical cell includes transferring an anode semi-solid suspension to an anode compartment defined at least in part by an anode current collector and an separator spaced apart from the anode collector. The method also includes transferring a cathode semi-solid suspension to a cathode compartment defined at least in part by a cathode current collector and the separator spaced apart from the cathode collector. The transferring of the anode semi-solid suspension to the anode compartment and the cathode semi-solid to the cathode compartment is such that a difference between a minimum distance and a maximum distance between the anode current collector and the separator is maintained within a predetermined tolerance. The method includes sealing the anode compartment and the cathode compartment.
Adopting a solid-phase microwave-assisted technique followed by thermal pyrolysis of N-functionalized graphene quantum dots, novel nitrogen-doped graphite-like (NGL) electrode materials were synthesized in this work and served as the anode for Li-ion batteries. The NGL anode demonstrated reversible capacity of 530 mAh g -1 at 0.1C, superior rate capability at high C rate operation (420 mAh g -1 at 5C), remarkable initial coulombic efficiency (>95.7%), and excellent cyclic stability along with high efficiency (>99.1%) during entire cycling. The NGL anode nanostructure enables improved lithium ion mobility and reversible Li + storage during cycling. The analysis of the Ragone plots revealed that the specific energy of NGL anode reaches to ca. 840 Wh kg -1 at the power density of 4200 W kg -1 . The diffusion coefficient of Li ions was measured as 1.69 × 10 -9 cm 2 s -1 for the NGL anode material, substantially improving over commonly used graphite electrodes (15–26 times higher Li + diffusivity). The high-rate cyclability as well as the cyclic stability of the NGL anodes were also confirmed via long-term cycling of full pouch cells assembled with ternary cathode and NGL anode. The robust design of the NGL anode materials introduced in this work, paves the way for designing next-generation lithium-ion batteries operating at ultra-high C rates.
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An organic light emitting device (OLED) is provided that includes a cathode and an anode; a blue emitting layer; and at least two hybrid red/green emitting layers. One of the at least two hybrid red/green emitting layers is a cathode side, red/green emitting layer that is disposed between the cathode and the blue emitting layer. The second of the at least two hybrid red/green emitting layers is an anode side, red/green emitting layer that is disposed between the blue emitting layer and the anode. The OLED emits white light.
Despite the long-established rocking-chair theory of lithium-ion batteries (LIBs), developing novel characterization methodology with higher spatiotemporal resolution facilitates a better understanding of the solid electrolyte interphase studies to shape the reaction mechanisms. In this work, we develop a Xenon ion plasma focused ion beam (Xe + PFIB)-based characterization technique to probe the cross-sectional interface of both ternary cathode and graphite anode electrodes, with the focus on revealing the chemical composition and distribution underneath the electrode surface by in-depth analysis of secondary ions. Particularly, the lithium fluoride is detected in the pristine cathode prior to contact with the electrolyte, reflecting that the electrode degradation is in the form of the loss of lithium inventory during electrode preparation. This degradation is related to the hydrolysis of the cathode material and the decomposition of the PVDF binder. Here, through the quantitative analysis of the transition-metal degradation products, manganese is found to be the dominant element in the newly formed inactive fluoride deposition on the cathode, while no transition metal signal can be found inside the anode electrode. These insights at high resolution implemented via a PFIB-based characterization technique not only enrich the understanding of the degradation mechanism in the LIBs but also identify and enable a high-sensitivity methodology to obtain the chemical survey at the subsurface, which will help remove the capacity-fade observed in most LIBs.
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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. Here, 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/cm 2 anode/2.7 mAh/cm 2 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/cm 2 ) 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.
Using renewable electricity to produce hydrogen fuel reduces reliance on fossil fuels. Proton exchange membrane water electrolyzers (PEMWEs) are the highest-performing commercialized technology. These devices split water into oxygen gas and hydrogen ions (protons) at the anode. The protons then migrate through an ion-conducting polymer membrane (ionomer) to be reduced to hydrogen gas at the cathode. Further, the anode reaction’s harsh environment requires the use of precious-metal catalysts, such as iridium oxide (IrO x ). Given the expense and scarcity, the design of electrodes that minimize the use of precious metals without compromising the requisite stability and activity is desired for large-scale hydrogen production. On page 791 of this issue, Shi et al. report that anchoring IrO x catalysts onto porous cerium-oxide (CeO x ) supports maintains performance even with much reduced precious metal use.
Aspects included herein include an electrolytic system for electrochemical reduction of carbon dioxide, the system comprising: a cathode comprising: a porous gas-diffusion membrane permeable to CO 2 ; an electrocatalyst layer adjacent to a second side of the gas-diffusion membrane; the electrocatalyst layer comprising: an electrically conductive catalyst; and a selectivity-determining organic material attached to at least a portion of the electrically conductive catalyst; wherein: the organic material is formed of a plurality of oligomers; each oligomer comprises a plurality of covalently bonded base units; each base unit comprises at least one heterocyclic group having at least one nitrogen in its structure; and an anion exchange membrane adjacent to the electrocatalyst layer and positioned between the anode and the cathode; wherein anion exchange membrane is characterized by anion conductivity and the cathode is in ionic communication with the anode via the anion exchange membrane.