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1.
Nat Commun ; 11(1): 5429, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33110084

RESUMO

The practical applications of lithium metal anodes in high-energy-density lithium metal batteries have been hindered by their formation and growth of lithium dendrites. Herein, we discover that certain protein could efficiently prevent and eliminate the growth of wispy lithium dendrites, leading to long cycle life and high Coulombic efficiency of lithium metal anodes. We contend that the protein molecules function as a "self-defense" agent, mitigating the formation of lithium embryos, thus mimicking natural, pathological immunization mechanisms. When added into the electrolyte, protein molecules are automatically adsorbed on the surface of lithium metal anodes, particularly on the tips of lithium buds, through spatial conformation and secondary structure transformation from α-helix to ß-sheets. This effectively changes the electric field distribution around the tips of lithium buds and results in homogeneous plating and stripping of lithium metal anodes. Furthermore, we develop a slow sustained-release strategy to overcome the limited dispersibility of protein in the ether-based electrolyte and achieve a remarkably enhanced cycling performance of more than 2000 cycles for lithium metal batteries.


Assuntos
Dendritos/química , Fontes de Energia Elétrica , Fibroínas/química , Lítio/química , Dendritos/metabolismo , Eletricidade , Eletrodos , Fibroínas/metabolismo , Lítio/metabolismo
2.
Anticancer Res ; 40(7): 3831-3837, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32620622

RESUMO

BACKGROUND/AIM: The ketogenic diet has recently gained interest as potential adjuvant therapy for cancer. Many researchers have endeavored to support this claim in vitro. One common model utilizes treatment with exogenous acetoacetate in lithium salt form (LiAcAc). We aimed to determine whether the effects of treatment with LiAcAc on cell viability, as reported in the literature, accurately reflect the influence of acetoacetate. MATERIALS AND METHODS: Breast cancer and normal cell lines were treated with acetoacetate, in lithium and sodium salt forms, and cell viability was assessed. RESULTS: The effect of LiAcAc on cells was mediated by Li ions. Our results showed that the cytotoxic effects of LiAcAc treatment were significantly similar to those caused by LiCl, and also treatment with NaAcAc did not cause any significant cytotoxic effect. CONCLUSION: Treatment of cells with LiAcAc is not a convincing in vitro model for studying ketogenic diet. These findings are highly important for interpreting previously published results, and for designing new experiments to study the ketogenic diet in vitro.


Assuntos
Acetoacetatos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Compostos de Lítio/farmacologia , Lítio/farmacologia , Acetoacetatos/química , Trifosfato de Adenosina/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Cátions Monovalentes/química , Cátions Monovalentes/farmacologia , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Lítio/química , Cloreto de Lítio/química , Cloreto de Lítio/farmacologia , Compostos de Lítio/química , Células MCF-7
3.
Chemosphere ; 260: 127623, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32668363

RESUMO

The global demand of lithium is rising steadily, and many industrially advanced countries may find it hard to secure an uninterrupted supply of lithium for meeting their manufacturing demands. Thus, innovative processes for lithium recovery from a wide range of natural reserves should be explored for meeting the future demands. In this study, a novel integrated approach was investigated by combining nanofiltration (NF), membrane distillation (MD) and precipitation processes for lithium recovery from salt-lake brines. Initially, the brine was filtered with an NF membrane for the separation of lithium ions (Li+) from competing ions such as Na+, K+, Ca2+ and Mg2+. The extent of permeation of metal ions by the NF membrane was governed by their hydrated ionic radii. Rejection by NF membrane was 42% for Li, 48% for Na and 61% for K, while both the divalent cations were effectively rejected (above 90%). Importantly, in the NF-permeate, Mg2+/Li+ mass ratio reduced to less than 6 (suggested for lithium recovery). The result showed that MD can enrich lithium with a concentration of 2.5 for raw brine and 5 for NF-treated brine. Following the enrichment of NF-permeate by the MD membrane, a two-stage precipitation method was used for the recovery of lithium. X-ray diffraction confirmed the precipitation of lithium as well as the formation of lithium carbonate crystals.


Assuntos
Lagos/química , Lítio/análise , Poluentes Químicos da Água/análise , Cátions Bivalentes , Destilação , Íons , Lítio/química , Sais , Sódio , Cloreto de Sódio , Poluentes Químicos da Água/química
4.
J Chromatogr A ; 1624: 461258, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540083

RESUMO

Lithium ion batteries are essential power sources in portable electronics, electric vehicles and as energy storage devices for renewable energies. During harsh battery cell operation as well as at elevated temperatures, the electrolyte decomposes and inter alia organo(fluoro)phosphates are formed due to hydrolysis of the conducting salt lithium hexafluorophosphate (LiPF6). Since these phosphorus-containing decomposition products possess a potential toxicity based on structural similarities compared to chemical warfare agents, quantification is of high interest regarding safety estimates. In this study, two comprehensive approaches for the precipitation of highly concentrated PF6¯ were investigated, allowing the separation from target analytes (organo(fluoro)phosphates) and improving mass spectrometry-based quantification techniques. Trimethyl phosphate was used as a polar, non-acidic organophosphate reference substance for method development via liquid chromatography-mass spectrometry. Six solvents were examined regarding precipitation reaction and selectivity. Thermally degraded electrolytes were analyzed after precipitation by means of gas chromatography-flame ionization detector, demonstrating the applicability of the developed sample preparations. The optimized method was applied successfully without influencing any volatile and non-acidic decomposition products. Using optimized conditions, a precipitation rate of 98% PF6¯ was achieved. Consequently, a fast and easy sample preparation for gas chromatographic investigations on lithium ion battery electrolytes was implemented, applicable for routine analysis.


Assuntos
Cromatografia Gasosa/métodos , Fontes de Energia Elétrica , Eletrólitos/química , Lítio/química , Organofosfatos/análise , Precipitação Química , Cromatografia Líquida de Alta Pressão , Íons , Organofosfatos/química , Solventes/química
5.
Carbohydr Polym ; 240: 116339, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32475594

RESUMO

Herein, a novel cellulose derivative has been synthesized and investigated as a nature-derived solid polymer electrolyte for lithium batteries. Cellulose is oxidized in a two-step process to dicarboxylic acid cellulose to allow for grafting low molecular weight poly(ethylene glycol) monomethyl ether (550 g mol-1) via Fischer-Speier esterification at the thus obtained carboxyl groups. The chemical structure of the synthesized materials is confirmed by Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy as well as X-ray diffraction. Incorporating lithium bis(trifluoromethane-sulfonyl)imide (LiTFSI) as conducting salt and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) ionic liquid as plasticizer results in the realization of an amorphous and solvent-free solid polymer electrolyte. These electrolyte membranes are characterized by high thermal and electrochemical stability and ionic conductivities of about 1×10-5 S cm-1 at 20 °C and 2.5×10-4 S cm-1 at 80 °C, which enables very stable lithium stripping and plating for more than 800 h.


Assuntos
Celulose/química , Fontes de Energia Elétrica , Lítio/química , Polietilenoglicóis/química , Polímeros/química , Eletrólitos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oxirredução , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície
6.
J Chromatogr A ; 1622: 461122, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32376021

RESUMO

To understand the overall processes behind the decomposition of state-of-the-art organic liquid electrolytes in lithium ion batteries (LIBs), it is necessary to investigate and quantify the permanent gases and light hydrocarbons evolving during electrolyte decomposition. In this work a convenient way of sampling gas from pouch cells without any previous preparation of the cell as well as a comprehensive gas chromatographic (GC) investigation of the gas phase is shown. A barrier discharge ionization detector (BID) was utilized for gas quantification and a multi component gas standard in combination with a gas mixing device was implemented to prepare calibration standards for validation. Therefore, sensitivity, linearity and reproducibility as well as the limits of detection (LOD) and limits of quantification (LOQ) were determined. Gas samples from pouch cells using LiNi0.6Mn0.2Co0.2O2 as cathode material and natural graphite (NMC622 ∣∣ NG) as anode material were analysed after formation. Gas volume and gas composition are key factors for a sufficient formation of LIBs and of interest for research with respect to the development of new materials and additives.


Assuntos
Cromatografia Gasosa/métodos , Fontes de Energia Elétrica , Gases/análise , Lítio , Cobalto , Eletrodos , Eletrólitos/química , Grafite , Íons , Limite de Detecção , Lítio/química , Manganês , Níquel , Reprodutibilidade dos Testes
7.
Chemosphere ; 254: 126670, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32325352

RESUMO

Ultrasound-assisted bioacid leaching was examined for the extraction of valuable metals from spent lithium ion batteries (LIBs). In this work, organic acids in lemon juice were used as the leaching agent together with H2O2. Three effective factors, namely solid/liquid (S/L) ratio, lemon juice percentage, and H2O2 volume percentage, were optimized using Response Surface Methodology (RSM). The optimal conditions were found to be 0.98% (w/v) S/L ratio, 57.8% (v/v) lemon juice and 8.07% (v/v) H2O2 in the leaching liquor, achieving recovery of 100% Li, 96% Co and 96% Ni. Furthermore, the individual effects of ultrasound, H2O2 and lemon juice on metal recovery were studied and the results showed that without H2O2 or lemon juice, the metal recovery rates decreased greatly while the absence of ultrasound reduced recovery rates to a much smaller extent, indicating that both H2O2 and lemon juice were essential in the leaching process. The effect of time on the metals recoveries was examined and results showed that Li and Co recovery reached 100% with the leaching time of 35 min. The modified shrinking core modeling results suggested that chemical reaction was the rate controlling step.


Assuntos
Fontes de Energia Elétrica , Peróxido de Hidrogênio/química , Lítio/química , Ondas Ultrassônicas , Metais , Reciclagem
8.
J Dairy Sci ; 103(6): 5509-5513, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32307153

RESUMO

The objectives of this study were to describe the stability of bovine whole-blood electrolytes, glucose, and lactate in samples collected in lithium heparin tubes and stored in thermoconductive modules immersed in ice water. A total of 99 Jersey cows (40 first-parity, 18 second-parity, and 41 third-parity or greater cows) from a commercial dairy farm in West Texas were enrolled between June and July 2018. Blood was collected from the jugular vein using a 60-mL polypropylene syringe and equally distributed into 5 spray-dried evacuated lithium heparin tubes. Baseline samples were analyzed within 90 s of collection using a benchtop blood gas analyzer. The remaining 4 tubes were stored in a thermoconductive, passive-temperature-regulating module inside a cooler with ice water. At 30 min and 2, 4, and 8 h post-collection, samples were removed from the temperature-regulating module, gently inverted for 10 s, and analyzed. Repeated-measures models were built to evaluate the effect of time on the stability of ionized Ca (iCa), ionized Mg (iMg), Na, K, Cl, glucose, and lactate. Most of the analytes investigated remained stable up to 8 h under ice water storage conditions before analysis, including iCa, iMg, Cl, glucose, and lactate. However, Na and K were significantly affected by delayed analysis: Na remained stable up to 4 h post-collection, but K was not stable starting at 2 h post-collection. The results of this study are useful in helping future researchers and consultants to recognize acceptable time delays between whole blood collection and processing or analysis for electrolytes, glucose, and lactate.


Assuntos
Coleta de Amostras Sanguíneas/veterinária , Bovinos/sangue , Eletrólitos/sangue , Heparina/química , Animais , Gasometria/veterinária , Glicemia/análise , Cálcio/sangue , Cloretos/sangue , Feminino , Ácido Láctico/sangue , Lítio/química , Magnésio/sangue , Potássio/sangue , Refrigeração/veterinária , Sódio/sangue , Texas , Fatores de Tempo
9.
Sensors (Basel) ; 20(7)2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32290270

RESUMO

An important research effort on the design of the magnetic particles is increasingly required to optimize the heat generation in biomedical applications, such as magnetic hyperthermia and heat-assisted drug release, considering the severe restrictions for the human body's exposure to an alternating magnetic field. Magnetic nanoparticles, considered in a broad sense as passive sensors, show the ability to detect an alternating magnetic field and to transduce it into a localized increase of temperature. In this context, the high biocompatibility, easy synthesis procedure and easily tunable magnetic properties of ferrite powders make them ideal candidates. In particular, the tailoring of their chemical composition and cation distribution allows the control of their magnetic properties, tuning them towards the strict demands of these heat-assisted biomedical applications. In this work, Co0.76Zn0.24Fe2O4, Li0.375Zn0.25Fe2.375O4 and ZnFe2O4 mixed-structure ferrite powders were synthesized in a 'dry gel' form by a sol-gel auto-combustion method. Their microstructural properties and cation distribution were obtained by X-ray diffraction characterization. Static and dynamic magnetic measurements were performed revealing the connection between the cation distribution and magnetic behavior. Particular attention was focused on the effect of Co2+ and Li+ ions on the magnetic properties at a magnetic field amplitude and the frequency values according to the practical demands of heat-assisted biomedical applications. In this context, the specific loss power (SLP) values were evaluated by ac-hysteresis losses and thermometric measurements at selected values of the dynamic magnetic fields.


Assuntos
Cobalto/química , Compostos Férricos/química , Lítio/química , Nanopartículas de Magnetita/química , Zinco/química , Materiais Biocompatíveis/química , Pós/química , Temperatura , Difração de Raios X
10.
Molecules ; 25(8)2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32295159

RESUMO

The ever-rising demands for energy dense electrochemical storage systems have been driving interests in beyond Li-ion batteries such as those based on lithium and magnesium metals. These high energy density batteries suffer from several challenges, several of which stem from the flammability/volatility of the electrolytes and/or instability of the electrolytes with either the negative, positive electrode or both. Recently, hydride-based electrolytes have been paving the way towards overcoming these issues. Namely, highly performing solid-state electrolytes have been reported and several key challenges in multivalent batteries were overcome. In this review, the classes of hydride-based electrolytes reported for energy dense batteries are discussed. Future perspectives are presented to guide research directions in this field.


Assuntos
Fontes de Energia Elétrica , Eletrólitos , Boratos/química , Eletroquímica/métodos , Líquidos Iônicos , Lítio/química , Magnésio/química , Sódio/química , Solventes/química
11.
J Colloid Interface Sci ; 573: 396-408, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32304949

RESUMO

Disordered carbons derived from biomass are herein efficiently used as an alternative anode in lithium-ion battery. Carbon precursor obtained from cherry pit is activated by using either KOH or H3PO4, to increase the specific surface area and enable porosity. Structure, morphology and chemical characteristics of the activated carbons are investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetry (TG), Raman spectroscopy, nitrogen and mercury porosimetry. The electrodes are studied in lithium half-cell by galvanostatic cycling, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The study evidences substantial effect of chemical activation on the carbon morphology, electrode resistance, and electrochemical performance. The materials reveal the typical profile of disordered carbon with initial irreversibility vanishing during cycles. Carbons activated by H3PO4 show higher capacity at the lower C-rates, while those activated by KOH reveal improved reversible capacity at the high currents, with efficiency approaching 100% upon initial cycles, and reversible capacity exceeding 175 mAh g-1. Therefore, the carbons and LiFePO4 cathode are combined in lithium-ion cells delivering 160 mAh g-1 at 2.8 V, with a retention exceeding 95% upon 200 cycles at C/3 rate. Hence, the carbons are suggested as environmentally sustainable anode for Li-ion battery.


Assuntos
Carbono/química , Fontes de Energia Elétrica , Lítio/química , Biomassa , Eletrodos , Tamanho da Partícula , Propriedades de Superfície
12.
PLoS One ; 15(3): e0227368, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130215

RESUMO

The idea that households produce and consume their own energy, that is, energy self-sufficiency at a very local level, captures the popular imagination and commands political support across parts of Europe. This paper investigates the technical and economic feasibility of household energy self-sufficiency in Switzerland, which can be seen as representative for other regions with a temperate climate, by 2050. We compare sixteen cases that vary across four dimensions: household type, building type, electricity demand reduction, and passenger vehicle use patterns. We assume that photovoltaic (PV) electricity supplies all energy, which implies a complete shift away from fossil fuel based heating and internal combustion engine vehicles. Two energy storage technologies are considered: short-term storage in lithium-ion batteries and long-term storage with hydrogen, requiring an electrolyzer, storage tank, and a fuel cell for electricity conversion. We examine technological feasibility and total system costs for self-sufficient households compared to base cases that rely on fossil fuels and the existing power grid. PV efficiency and available rooftop/facade area are most critical with respect to the overall energy balance. Single-family dwellings with profound electricity demand reduction and urban mobility patterns achieve self-sufficiency most easily. Multi-family buildings with conventional electricity demand and rural mobility patterns can only be self-sufficient if PV efficiency increases, and all of the roof plus most of the facade can be covered with PV. All self-sufficient cases are technically feasible but more expensive than fully electrified grid-connected cases. Self-sufficiency may even become cost-competitive in some cases depending on storage and fossil fuel prices. Thus, if political measures improve their financial attractiveness or individuals decide to shoulder the necessary investments, self-sufficient buildings may start to become increasingly prevalent.


Assuntos
Poluição do Ar/prevenção & controle , Clima , Indústria da Construção/métodos , Fontes de Energia Elétrica/economia , Semicondutores/economia , Automóveis/economia , Mudança Climática , Indústria da Construção/economia , Indústria da Construção/tendências , Fontes de Energia Elétrica/tendências , Eletrólise/economia , Estudos de Viabilidade , Combustíveis Fósseis/efeitos adversos , Humanos , Hidrogênio/química , Hidrogênio/economia , Lítio/química , Lítio/economia , Densidade Demográfica , Suíça
13.
Chemosphere ; 250: 126273, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32120147

RESUMO

Metal/Air batteries are being developed and soon could become competitive with other battery technologies already in the market, such as Li-ion battery. The main problem to be addressed is the cyclability, although some progress has been recently achieved. A Life Cycle Assessment (LCA) of the manufacturing process of a Zn/Air battery is presented in this article, including raw extraction and process of materials and battery assembly at laboratory scale (cradle to gate approach). The results indicate that Zn/Air battery can be fabricated with low environmental impacts in most categories and only four deserve attention (still being low impacts), such as Human Toxicity (cancer and non-cancer), Freshwater Ecotoxicity and Resource Depletion (the later one depending mainly on Zn use, which is not a critical material, but has a strong impact on this category). Cathode fabrication arises as the subassembly with higher impacts, followed by membrane, then anode and finally electrolyte. An economic cost calculation indicates that if cyclability of Zn/Air batteries is achieved, they can become competitive with other technologies already in the market.


Assuntos
Ar , Fontes de Energia Elétrica/efeitos adversos , Meio Ambiente , Zinco/química , Fontes de Energia Elétrica/economia , Eletrodos , Humanos , Lítio/química , Metais/química
14.
Chem Commun (Camb) ; 56(26): 3749-3752, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32125334

RESUMO

A BN indole-containing aromatic scaffold has been synthesized and the cation-π binding ability characterized by nuclear magnetic resonance (NMR) monitored titrations. The resulting chemical shifts were analyzed using a non-linear curve fitting procedure and the extracted association constants (Ka's) compared with the natural indole scaffold. Computations were also performed to support our findings. This work shows that incorporation of a B-N bond in place of a C-C bond in an aromatic system slightly lowers the cation-π binding ability of the arene's π-system with simple cations.


Assuntos
Indóis/química , Lítio/química , Sódio/química , Espectroscopia de Ressonância Magnética
15.
Protein Pept Lett ; 27(8): 763-769, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32133946

RESUMO

BACKGROUND: Despite the fact that lithium is not a biologically essential metallic element, its pharmacological properties are well known and human exposure to lithium is increasingly possible because of its used in aerospace industry and in batteries. OBJECTIVE: Lithium-protein interactions are therefore interesting and the surveys of the structures of lithium-protein complexes is described in this paper. METHODS: A high quality non-redundant set of lithium containing protein crystal structures was extracted from the Protein Data Bank and the stereochemistry of the lithium first coordination sphere was examined in detail. RESULTS: Four main observations were reported: (i) lithium interacts preferably with oxygen atoms; (ii) preferably with side-chain atoms; (iii) preferably with Asp or Glu carboxylates; (iv) the coordination number tends to be four with stereochemical parameters similar to those observed in small molecules containing lithium. CONCLUSION: Although structural information on lithium-protein, available from the Protein Data Bank, is relatively scarce, these trends appears to be so clear that one may suppose that they will be confirmed by further data that will join the Protein Data Bank in the future.


Assuntos
Bases de Dados de Proteínas , Lítio/química , Modelos Moleculares , Proteínas/química , Cristalografia por Raios X , Humanos
16.
Molecules ; 25(5)2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32120977

RESUMO

Downsizing well-established materials to the nanoscale is a key route to novel functionalities, in particular if different functionalities are merged in hybrid nanomaterials. Hybrid carbon-based hierarchical nanostructures are particularly promising for electrochemical energy storage since they combine benefits of nanosize effects, enhanced electrical conductivity and integrity of bulk materials. We show that endohedral multiwalled carbon nanotubes (CNT) encapsulating high-capacity (here: conversion and alloying) electrode materials have a high potential for use in anode materials for lithium-ion batteries (LIB). There are two essential characteristics of filled CNT relevant for application in electrochemical energy storage: (1) rigid hollow cavities of the CNT provide upper limits for nanoparticles in their inner cavities which are both separated from the fillings of other CNT and protected against degradation. In particular, the CNT shells resist strong volume changes of encapsulates in response to electrochemical cycling, which in conventional conversion and alloying materials hinders application in energy storage devices. (2) Carbon mantles ensure electrical contact to the active material as they are unaffected by potential cracks of the encapsulate and form a stable conductive network in the electrode compound. Our studies confirm that encapsulates are electrochemically active and can achieve full theoretical reversible capacity. The results imply that encapsulating nanostructures inside CNT can provide a route to new high-performance nanocomposite anode materials for LIB.


Assuntos
Técnicas Eletroquímicas/métodos , Íons/química , Lítio/química , Nanotubos de Carbono/química , Cobalto/química , Condutividade Elétrica , Fontes de Energia Elétrica , Eletrodos , Compostos Férricos/química , Compostos de Manganês/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanocompostos/química , Nanocompostos/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Óxidos/química , Estanho/química
17.
ACS Appl Mater Interfaces ; 12(12): 13950-13958, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32125148

RESUMO

The stringent safety and sustainability requirements for electrolytes used in lithium batteries have led to significant research efforts into alternative materials. Here, a quasi-solid electrolyte based on biodegradable bacterial cellulose (BC) was successfully synthesized via a simple ball milling method. The BC provides plenty of sites for the attachment of ionic liquid electrolytes (ILEs) as well as ion transport channels. Moreover, the O-H groups contained in the BC molecular chains interact with anions in ILEs to form hydrogen bonds, which promotes the dissociation of the lithium salts. The prepared electrolytes (BC-ILEs) have good thermal stability with a decomposition temperature exceeding 300 °C and high ionic conductivities. The Li/BC-ILE/LiFePO4 battery exhibits remarkable electrochemical performance. More importantly, the results of the Fehling test verify that the electrolyte can be degraded by cellulase. The quasi-solid electrolyte broadens the range of electrolytes for lithium batteries and provides new avenues to explore safe and eco-friendly materials.


Assuntos
Celulose/química , Fontes de Energia Elétrica , Eletrólitos/química , Lítio/química , Condutividade Elétrica , Líquidos Iônicos/química
18.
ChemSusChem ; 13(7): 1856-1863, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32026541

RESUMO

Although several recent publications describe cathodes for electrochemical energy storage materials made from regrown biomass in aqueous electrolytes, their transfer to lithium-organic batteries is challenging. To gain a deeper understanding, we investigate the influences on charge storage in model systems based on biomass-derived, redox-active compounds and comparable structures. Hybrid materials from these model polymers and porous carbon are compared to determine precisely the causes of exceptional capacity in lithium-organic systems. Besides redox activity, particularly, wettability influences capacity of the composites greatly. Furthermore, in addition to biomass-derived molecules with catechol functionalities, which are described commonly as redox-active species in lithium-bio-organic systems, we further describe guaiacol groups as a promising alternative for the first time and compare the performance of the respective compounds.


Assuntos
Aldeídos/química , Catecóis/química , Fontes de Energia Elétrica , Guaiacol/química , Polímeros/química , Eletroquímica , Lítio/química , Oxirredução , Porosidade , Molhabilidade
19.
Molecules ; 25(4)2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32079341

RESUMO

Commercial micrometer silicon (Si) powder was investigated as a potential anode material for lithium ion (Li-ion) batteries. The characterization of this powder showed the mean particle size of approx.75.2 nm, BET surface area of 10.6 m2/g and average pore size of 0.56 nm. Its band gap was estimated to 1.35 eV as determined using UV-Vis diffuse reflectance spectra. In order to increase the surface area and porosity which is important for Li-ion batteries, the starting Si powder was ball-milled and threatened by metal-assisted chemical etching. The mechanochemical treatment resulted in decrease of the particle size from 75 nm to 29 nm, an increase of the BET surface area and average pore size to 16.7 m2/g and 1.26 nm, respectively, and broadening of the X-ray powder diffraction (XRD) lines. The XRD patterns of silver metal-assisted chemical etching (MACE) sample showed strong and narrow diffraction lines typical for powder silicon and low-intensity diffraction lines typical for silver. The metal-assisted chemical etching of starting Si material resulted in a decrease of surface area to 7.3 m2/g and an increase of the average pore size to 3.44 nm. These three materials were used as the anode material in lithium-ion cells, and their electrochemical properties were investigated by cyclic voltammetry and galvanostatic charge-discharge cycles. The enhanced electrochemical performance of the sample prepared by MACE is attributed to increase in pore size, which are large enough for easy lithiation. These are the positive aspects of the application of MACE in the development of an anode material for Li-ion batteries.


Assuntos
Fontes de Energia Elétrica , Lítio/química , Nanoestruturas/química , Silício/química , Técnicas Eletroquímicas , Eletrodos , Íons , Nitrogênio/química , Tamanho da Partícula , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Difração de Raios X
20.
Macromol Rapid Commun ; 41(7): e1900622, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32077181

RESUMO

The most daunting challenge of solid polymer electrolytes (SPEs) is the development of materials with simultaneously high ionic conductivity and mechanical strength. Herein, SPEs of lithium bis-(trifluoromethanesulfonyl)imide (LiTFSI)-doped poly(propylene monothiocarbonate)-b-poly(ethylene oxide) (PPMTC-b-PEO) block copolymers (BCPs) with both blocks associating with Li+ ions are prepared. It is found that the PPMTC-b-PEO/LiTFSI electrolytes with double conductive phases exhibit much higher ionic conductivity (2 × 10-4 S cm-1 at r.t.) than the BCP electrolytes with a single conductive phase. Concurrently, the storage moduli of PPMTCn -b-PEO44 /LiTFSI electrolytes are ≈1-4 orders of magnitude higher than that of the neat PEO/LiTFSI electrolytes. Therefore, simultaneous improvement of ionic conductivity and mechanical properties is achieved by construction of a microphase-separated and disordered structure with double conductive phases.


Assuntos
Nanopartículas/química , Polímeros/química , Condutividade Elétrica , Fontes de Energia Elétrica , Eletrólitos/química , Lítio/química , Compostos Organometálicos/química , Estresse Mecânico
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