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1.
Small ; 20(8): e2305576, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37821400

RESUMO

Garnet solid electrolyte Li6.4 La3 Zr1.4 Ta0.6 O12 (LLZTO) is an excellent inorganic ceramic-type solid electrolyte; however, the presence of Li2 CO3 impurities on its surface hinders Li-ion transport and increases the interface impedance. In contrast to traditional methods of mechanical polishing, acid corrosion, and high-temperature reduction for removing Li2 CO3 , herein, a straightforward "waste-to-treasure" strategy is proposed to transform Li2 CO3 into Li3 PO4 and LiF in LiPF6 solution under 60 °C. It is found that the formation of Li3 PO4 during LLZTO pretreatment facilitates rapid Li-ion transport and enhances ionic conductivity, and the LLZTO/PAN composite polymer electrolyte shows the highest Li-ion transference number of 0.63. Additionally, the dense LiF layer serves to safeguard the internal garnet solid electrolyte against solvent decomposition-induced chemical adsorption. Symmetric Li/Li cells assembled with treated LLZTO/PAN composite electrolyte exhibit a critical current density of 1.1 mA cm-2 and a long lifespan of up to 700 h at a current density of 0.2 mA cm-2 . The Li/LiFePO4 solid-state cells demonstrate stable cycling performances for 141 mAh g-1 at 0.5 C, with capacity retention of 93.6% after 190 cycles. This work presents a novel approach to converting waste into valuable resources, offering the advantages of simple processes, and minimal side reactions.

2.
Small ; 20(33): e2400185, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38530076

RESUMO

Designing heterogeneous electrolytes with superior interface charge transfer is promising for low-temperature solid oxide fuel cells (LT-SOFCs). However, a rational construction with optimal interfaces to maximize ionic conduction remains a challenge. Here an in situ phase-transformation strategy is demonstrated to prepare a highly conductive heterogeneous electrolyte. A pristine LiNiO2-TiO2 nanocomposite precursor undergoes chemical reactions and phase-transformation upon heating and feeding H2, destroying the original phases, and forming new species, including an amorphous Li2CO3 scaffold within a (Ni, Co, Al, and Ti)-oxide (NCAT) matrix. It creates an intertwining and continuous network inside the electrolyte with plentiful interfaces. The in situ formed NCAT/Li2CO3 heterogeneous electrolyte displays superior ionic conductivity and impressive fuel cell performance. This work emphasizes the potential of rational heterogeneous structure design and interface engineering for LT-SOFC electrolyte through an in situ phase-transform approach. The generated interfaces enhance ion transport, presenting an opportunity for further optimizing electrolyte candidates, and lowering the operating temperatures of SOFCs.

3.
Molecules ; 29(9)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38731525

RESUMO

Li2CO3 is the most tenacious parasitic solid-state product in lithium-air batteries (LABs). Developing suitable redox mediators (RMs) is an efficient way to address the Li2CO3 issue, but only a few RMs have been investigated to date, and their mechanism of action also remains elusive. Herein, we investigate the effects of the central metal ion in binuclear metal phthalocyanines on the catalysis of Li2CO3 decomposition, namely binuclear cobalt phthalocyanine (bi-CoPc) and binuclear cobalt manganese phthalocyanine (bi-CoMnPc). Density functional theory (DFT) calculations indicate that the key intermediate peroxydicarbonate (*C2O62-) is stabilized by bi-CoPc2+ and bi-CoMnPc3+, which is accountable for their excellent catalytic effects. With one central metal ion substituted by manganese for cobalt, the bi-CoMnPc's second active redox couple shifts from the second Co(II)/Co(III) couple in the central metal ion to the Pc(-2)/Pc(-1) couple in the phthalocyanine ring. In artificial dry air (N2-O2, 78:22, v/v), the LAB cell with bi-CoMnPc in electrolyte exhibited 261 cycles under a fixed capacity of 500 mAh g-1carbon and current density of 100 mA g-1carbon, significantly better than the RM-free cell (62 cycles) and the cell with bi-CoPc (193 cycles).

4.
Environ Res ; 238(Pt 1): 117148, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37716391

RESUMO

Waste three-way catalysts (TWCs) have attracted much attention due to the presence of platinum group metals (PGMs) and hazardous substances such as heavy metals and organic matter. The extraction of PGMs from waste TWCs using hydrochloric acid (HCl) has been extensively researched. However, the addition of oxidizing agents like H2O2 and aqua regia is necessary to facilitate PGMs dissolution, which poses significant environmental and operational hazards. Hence, developing a green PGMs recovery process without oxidants is imperative. Previously, we investigated the process of Li2CO3 calcination pretreatment to enhance the leaching of PGMs from waste TWCs by HCl, focusing on the process and mechanism of Li2CO3 calcination pretreatment. In this study, we focused on the leaching process of HCl after pretreatment. Our investigation includes a detailed examination of leaching kinetics and mechanisms. The optimal leaching conditions were: leaching temperature of 150 °C, leaching time of 2 h, HCl concentration of 12 M, and liquid-solid ratio of 10 mL/g. The experiments resulted in maximum leaching rates of about 96%, 97%, and 97% for Pt, Pd, and Rh, respectively. However, given the presence of heavy metals, attention needs to be paid to the harmless treatment of waste acids and leaching residues. The Pt and Pd leaching process is controlled by a mixture of interfacial chemical reactions and internal diffusion, and dominated by internal diffusion, while the leaching process of Rh is controlled by interfacial chemical reactions. Li+ in Li2PtO3, Li2PdO2, and Li2RhO3 preferentially leached and underwent ion-exchange reactions with H+, promoting the dissolution of Pt, Pd, and Rh in HCl.


Assuntos
Metais Pesados , Platina , Ácido Clorídrico/química , Peróxido de Hidrogênio/química , Metais Pesados/química , Lítio , Oxidantes , Reciclagem
5.
Molecules ; 28(9)2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37175314

RESUMO

The large-scale implementations of lithium iron phosphate (LFP) batteries for energy storage systems have been gaining attention around the world due to their quality of high technological maturity and flexible configuration. Unfortunately, the exponential production of LFP batteries is accompanied by an annual accumulation of spent batteries and a premature consumption of the lithium resource. Recycling souring critical battery materials such as Li2CO3 is essential to reduce the supply chain risk and achieve net carbon neutrality goals. During the recovery of Li2CO3, impurity removal is the most crucial step in the hydrometallurgy process of spent LiFePO4, which determines the purity of Li2CO3. By investigating and comparing the results of impurity elimination from the purified Li+-containing liquids with strong and weak alkalis under identical pH conditions, respectively, a strategy based on an alkali mixture has been proposed. The purified Li+-containing liquid was, thereafter, concentrated and sodium carbonate was added in order to precipitate Li2CO3. As a result, a high purity Li2CO3 (99.51%) of battery grade was obtained. LiFePO4 prepared with the recovered Li2CO3 and FePO4 as raw materials also displayed a comparative high capacity and stable cycle performance to the commercial product and further verified the electrochemical activity of the recovered materials.

6.
Small ; 17(26): e2100642, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34081392

RESUMO

Directly converting and storing abundant solar energy in next-generation energy storage devices is of central importance to build a sustainable society. Herein, a new prototype of a light-promoted rechargeable and flexible Li-CO2 battery with a TiO2 /carbon cloth (CC) cathode is reported for the direct utilization of solar energy to promote the kinetics of the carbon dioxide reduction reaction and carbon dioxide evolution reaction (CO2 ER). Under illumination, photoelectrons are generated in the conduction band of TiO2 /CC, followed by the enhancing diffusion of electrons and lithium ions during the discharge process. The photoelectrons on the cathode surface can regulate the morphology of the discharge product Li2 CO3 , contributing to boosting the kinetics of the subsequent CO2 ER process. In the reverse charge process, photogenerated holes can favor the decomposition of Li2 CO3 , leading to a negative charge potential of 2.88 V without increased polarization over ≈60 h of cycling. Owing to an ultralow overpotential of 0.06 V between the discharge and charge process, an ultrahigh energy efficiency of 97.9% is attained under illumination. The introduction of a light-promoted flexible Li-CO2 battery can pave the way toward developing the use of solar energy to address the charging overpotential of conventional Li-CO2 batteries.

7.
Bull Exp Biol Med ; 170(2): 246-250, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33263850

RESUMO

We studied the effects of lithium carbonate on the cell cycle, apoptosis, and autophagy in hepatocellular carcinoma-29 cells (HCC-29) in vitro. Flow cytofluorometry analysis revealed accumulation of G2/M-phase HCC-29 cells and increase in the number of apoptotic cells in 48 h after administration of 5 mM lithium carbonate. Induction of autophagy in HCC-29 cells was detected by transmission electron microscopy and immunofluorescence staining. Thus, lithium carbonate produces an antitumor effect by arresting cell cycle in the G2/M-phase and induction of apoptosis and autophagy in HCC-29 cells, which confirms the lithium potential as a promising drug for the treatment of hepatocellular carcinoma.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Carbonato de Lítio/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Corantes Fluorescentes/farmacologia , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Transdução de Sinais
8.
Small ; 15(29): e1803246, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30345634

RESUMO

Rechargeable Li-CO2 batteries have attracted worldwide attention due to the capability of CO2 capture and superhigh energy density. However, they still suffer from poor cycling performance and huge overpotential. Thus, it is essential to explore highly efficient catalysts to improve the electrochemical performance of Li-CO2 batteries. Here, phytic acid (PA)-cross-linked ruthenium complexes and melamine are used as precursors to design and synthesize RuP2 nanoparticles highly dispersed on N, P dual-doped carbon films (RuP2 -NPCFs), and the obtained RuP2 -NPCF is further applied as the catalytic cathode for Li-CO2 batteries. RuP2 nanoparticles that are uniformly deposited on the surface of NPCF show enhanced catalytic activity to decompose Li2 CO3 at low charge overpotential. In addition, the NPCF its with porous structure in RuP2 -NPCF provides superior electrical conductivity, high electrochemical stability, and enough ion/electron and space for the reversible reaction in Li-CO2 batteries. Hence, the RuP2 -NPCF cathode delivers a superior reversible discharge capacity of 11951 mAh g-1 , and achieves excellent cyclability for more than 200 cycles with low overpotentials (<1.3 V) at the fixed capacity of 1000 mAh g-1 . This work paves a new way to design more effective catalysts for Li-CO2 batteries.

9.
Nano Lett ; 17(3): 1417-1424, 2017 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-28186765

RESUMO

Instability of carbon-based oxygen electrodes and incomplete decomposition of Li2CO3 during charge process are critical barriers for rechargeable Li-O2 batteries. Here we report the complete decomposition of Li2CO3 in Li-O2 batteries using the ultrafine iridium-decorated boron carbide (Ir/B4C) nanocomposite as a noncarbon based oxygen electrode. The systematic investigation on charging the Li2CO3 preloaded Ir/B4C electrode in an ether-based electrolyte demonstrates that the Ir/B4C electrode can decompose Li2CO3 with an efficiency close to 100% at a voltage below 4.37 V. In contrast, the bare B4C without Ir electrocatalyst can only decompose 4.7% of the preloaded Li2CO3. Theoretical analysis indicates that the high efficiency decomposition of Li2CO3 can be attributed to the synergistic effects of Ir and B4C. Ir has a high affinity for oxygen species, which could lower the energy barrier for electrochemical oxidation of Li2CO3. B4C exhibits much higher chemical and electrochemical stability than carbon-based electrodes and high catalytic activity for Li-O2 reactions. A Li-O2 battery using Ir/B4C as the oxygen electrode material shows highly enhanced cycling stability than those using the bare B4C oxygen electrode. Further development of these stable oxygen-electrodes could accelerate practical applications of Li-O2 batteries.

10.
Nano Lett ; 16(3): 2011-6, 2016 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-26889564

RESUMO

The solid electrolyte interphase (SEI), a passivation layer formed on electrodes, is critical to battery performance and durability. The inorganic components in SEI, including lithium carbonate (Li2CO3) and lithium fluoride (LiF), provide both mechanical and chemical protection, meanwhile control lithium ion transport. Although both Li2CO3 and LiF have relatively low ionic conductivity, we found, surprisingly, that the contact between Li2CO3 and LiF can promote space charge accumulation along their interfaces, which generates a higher ionic carrier concentration and significantly improves lithium ion transport and reduces electron leakage. The synergetic effect of the two inorganic components leads to high current efficiency and long cycle stability.

11.
Angew Chem Int Ed Engl ; 56(31): 9126-9130, 2017 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-28612470

RESUMO

The utilization of CO2 in Li-CO2 batteries is attracting extensive attention. However, the poor rechargeability and low applied current density have remained the Achilles' heel of this energy device. The gel polymer electrolyte (GPE), which is composed of a polymer matrix filled with tetraglyme-based liquid electrolyte, was used to fabricate a rechargeable Li-CO2 battery with a carbon nanotube-based gas electrode. The discharge product of Li2 CO3 formed in the GPE-based Li-CO2 battery exhibits a particle-shaped morphology with poor crystallinity, which is different from the contiguous polymer-like and crystalline discharge product in conventional Li-CO2 battery using a liquid electrolyte. Accordingly, the GPE-based battery shows much improved electrochemical performance. The achieved cycle life (60 cycles) and rate capability (maximum applied current density of 500 mA g-1 ) are much higher than most of previous reports, which points a new way to develop high-performance Li-CO2 batteries.

12.
Adv Mater ; : e2406856, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39177199

RESUMO

Catalytic reactions mainly depend on the adsorption properties of reactants on the catalyst, which provides a perspective for the design of reversible lithium-carbon dioxide (Li-CO2) batteries including CO2 reduction (CO2RR) and CO2 evolution (CO2ER) reactions. However, due to the complex reaction process, the relationship between the adsorption configuration and CO2RR/CO2ER catalytic activity is still unclear in Li─CO2 batteries. Herein, taking Co3S4 as a model system, nickel (Ni substitution in the tetrahedral site to activate cobalt (Co) atom for forming multiatom catalytic domains in NiCo2S4 is utilized. Benefiting from the special geometric and electronic structures, NiCo2S4 exhibits an optimized adsorption configuration of lithium carbonate (Li2CO3), promoting its effective activation and decomposition. As a result, the Li-CO2 batteries with NiCo2S4 cathode exhibit remarkable electrochemical performance in terms of low potential gap of 0.42 V and high energy efficiency of 88.7%. This work provides a unique perspective for the development of highly efficient catalysts in Li-CO2 batteries.

13.
Materials (Basel) ; 17(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38673099

RESUMO

Alite-ye'elimite-belite-ferrite cement (AYBFC) integrates the advantages of calcium sulfoaluminate cement and Portland cement, but its ultra-early strength needs to be further improved when applied to rush repair and construction works. In this study, the ultra-early strength of AYBFC was improved using lithium carbonate (Li2CO3) and superplasticizer. The results showed that an appropriate amount of Li2CO3 could significantly improve the ultra-early strength of AYBFC, since it was capable of promoting the hydration reaction of AYBFC. After polycarboxylate superplasticizer was doped on this basis, the ultra-early compressive strength of AYBFC was further improved. This was because the superplasticizer could markedly enhance the matrix compactness despite its inhibitory effect on the hydration reaction of cement and the generation of hydration products.

14.
Adv Mater ; 36(13): e2312159, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38117030

RESUMO

Developing sacrificial cathode prelithiation technology to compensate for active lithium loss is vital for improving the energy density of lithium-ion battery full-cells. Li2CO3 owns high theoretical specific capacity, superior air stability, but poor conductivity as an insulator, acting as a promising but challenging prelithiation agent candidate. Herein, extracting a trace amount of Co from LiCoO2 (LCO), a lattice engineering is developed through substituting Li sites with Co and inducing Li defects to obtain a composite structure consisting of (Li0.906Co0.043▫0.051)2CO2.934 and ball milled LiCoO2 (Co-Li2CO3@LCO). Notably, both the bandgap and Li─O bond strength have essentially declined in this structure. Benefiting from the synergistic effect of Li defects and bulk phase catalytic regulation of Co, the potential of Li2CO3 deep decomposition significantly decreases from typical >4.7 to ≈4.25 V versus Li/Li+, presenting >600 mAh g-1 compensation capacity. Impressively, coupling 5 wt% Co-Li2CO3@LCO within NCM-811 cathode, 235 Wh kg-1 pouch-type full-cell is achieved, performing 88% capacity retention after 1000 cycles.

15.
Environ Sci Pollut Res Int ; 31(42): 54589-54602, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39207615

RESUMO

In this study, the protective role of Urtica dioica extract (Udex) against Li2CO3 toxicity in Allium cepa L. was investigated using various parameters such as germination rates, root growth, weight gain, mitotic index (MI), malondialdehyde (MDA), micronucleus (MN), antioxidant enzyme activity, chromosomal abnormalities (CAs) and anatomical changes. As the biological activity of Udex is related to its active content, the profile of phenolic compounds was determined by LC-MS/MS analysis. Li2CO3 caused abnormalities in the tested parameters and serious regressions in germination parameters. Application of 100 mg/L Li2CO3 reduced the chlorophyll a and b contents by 73.04% and 65.7%, respectively. Li2CO3 application exhibited a cytotoxic effect by inducing significant decreases in MI and increases in the frequency of MN, and also showed a genotoxic effect by causing CAs. After 100 mg/L Li2CO3 treatment, MDA, proline, superoxide dismutase, and catalase levels increased by 54.9%, 58.5%, 47.8%, and 52.3%, respectively. Li2CO3 and Udex co-administration resulted in a regression in increased biochemical parameters and genotoxicity parameters, and an improvement in germination parameters. Furthermore, Udex demonstrated efficacy in mitigating the detrimental effects of Li2CO3 on the root tip, particularly in the 200 µg/mL Udex-treated group. The thickening of the cortex cell wall and conduction tissue, which is commonly induced by Li2CO3, was not observed in the Udex-treated group. The protective effect of Udex can be explained by the phenolic compounds it contains. Rutin was detected as the major component in Udex and other phenolics were listed according to their presence rate as protecatechuic acid > caffeic acid > p-coumaric acid > syringic acid > rosemarinic acid > epicatechin. Li ions, which increase in the environment after industrialization, are an important environmental pollutant and exhibit toxicity that affects many pathways in organisms. Scientific research should not only detect these toxic effects but also develop solutions to such problems. In this study, it was determined that the Udex application had a toxicity-reducing role against Li2CO3 toxicity. Also, it has been demonstrated that A. cepa is an important indicator in determining this toxicity and toxicity-reducing applications.


Assuntos
Fenóis , Extratos Vegetais , Urtica dioica , Urtica dioica/química , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Extratos Vegetais/química , Fenóis/toxicidade , Cromatografia Líquida , Espectrometria de Massas em Tandem , Cebolas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Espectrometria de Massa com Cromatografia Líquida
16.
ACS Appl Mater Interfaces ; 15(38): 44921-44931, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37708444

RESUMO

The irreversible capacity loss of lithium-ion batteries during initial cycling directly leads to a decrease in energy density, and promising lithium cathode replenishment can significantly alleviate this problem. In response to the problems of complex preparation, instability in air, and unfavorable residue of the conventional cathode lithium replenishment materials, a Li2CO3/carbon nanocomposite is prepared and utilized as the lithium replenishment material. With high-speed ball-milling, a nanocomposite with a tight embedment structured Li2CO3/Ketjen Black (KB) composite composed of nanosized Li2CO3 and KB is synthesized. The decomposition potential of Li2CO3 is effectively decreased to 3.8 V, and the amount of the active lithium ion being released is significantly increased, corresponding to a specific capacity of 645.2 mAh·g-1 during the initial charging cycle. It has been introduced into the full-cells composed of the NCM523 cathode and graphite anode, resulting in a capacity increase of 44 mAh·g-1 in the initial cycle and a 26.4% improvement in capacity retention over 100 cycles. The working mechanism of the Li2CO3/KB nanocomposite as the lithium replenishment agent has been discussed. The outcome of the work provides a practically feasible route to realize lithium-ion battery technology with improved energy density and cycling life.

17.
ACS Appl Mater Interfaces ; 15(38): 45465-45474, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37709730

RESUMO

Garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZTO) is a highly promising solid-state lithium metal battery electrolyte due to its exceptional ionic conductivity and electrochemical stability. However, when exposed to air, a passivation layer can be spontaneously formed on the garnet-type electrolyte, deteriorating its wettability with metallic lithium (Li) and impeding the lithium ion transfer at the Li-garnet electrolyte interface. The passivation layer is considered a critical issue for garnet-type solid electrolytes. Despite intensive research, the formation mechanism of the passivation film remains poorly understood. The key to elucidating the formation mechanism is to obtain a pristine garnet electrolyte surface and study how the pristine garnet electrolyte interacts with air. In this study, different passivation layer removal pretreatments were performed to expose pristine garnet electrolytes, and their impacts on the samples were systematically studied. The results reveal the overlooked negative impacts of vacuum annealing and acid treatment on LLZTO, which are indicated by the severe loss of Li and O and the formation of additional Li-depleted metal oxides. It was confirmed that argon annealing is the only viable approach to remove the passivation layer without introducing concomitant contaminations to LLZTO. Based on this method, we directly evidenced the formation of LiOH on LLZTO under rarefied air using quasi-in situ X-ray photoelectron spectroscopy. It was confirmed that the loss of Li and O ions, rather than Li+/H+ exchange, drives the formation of LiOH in the passivation layer. These results not only provide a better understanding of the surface and interface chemistry of LLZTO but also reveal a reliable surface treatment for the LLZTO sample.

18.
Front Chem ; 11: 1264593, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37720718

RESUMO

Li-O2 batteries are a promising technology for the upcoming energy storage requirements because of their high theoretical specific energy density of 11,680 Wh kg-1. Currently, the actual capacity of Li-O2 batteries is much lower than this theoretical value. In many studies, perovskites have been applied as catalysts to improve the air electrode reactions in Li-O2 batteries. The effects of structure and doping on the catalytic activity of perovskites are still unclear. La1-xSrxCoO3-δ (x = 0.1, 0.3, and 0.5) and La0.9Sr0.1YbO3-δ mixed with carbon black (Vulcan XC500 or Super P) were used as air electrode catalysts. Electrochemical characterizations were conducted using a Swagelok-type cell. The charge-discharge capacity and cyclic voltammetry (CV) performance were investigated in this study. The La1-xSrxCoO3-δ (x = 0.1, 0.3, and 0.5) is a suitable cathode catalyst for Li-O2 batteries. In this study, the La0.5Sr0.5CoO3-δ/Super P cathode demonstrated the highest discharge capacity (6,032 mAh g-1). This excellent performance was attributed to the large reaction area and enhanced Li2CO3 generation.

19.
Adv Mater ; 35(12): e2208951, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36639140

RESUMO

Poor ion and high electron transport at the grain boundaries (GBs) of ceramic electrolytes are the primary reasons for lithium filament infiltration and short-circuiting of all-solid-state lithium metal batteries (ASLMBs). Herein, it is discovered that Li2 CO3 at the GBs of Li7 La3 Zr2 O12 (LLZO) sheets is reduced to highly electron-conductive LiCx during cycling, resulting in lithium penetration of LLZO. The ionic and electronic conductivity of the GBs within LLZO can be simultaneously tuned using sintered Li3 AlF6 . The generated LiAlO2 (LAO) infusion and F-doping at the GBs of LLZO (LAO-LLZOF) significantly reduce the Li2 CO3 content and broaden the energy bandgap of LLZO, which decreases the electronic conductivity of LAO-LLZOF. LAO forms a 3D continuous ion transport network at the GB that significantly improves the total ionic conductivity. Lithium penetration within LLZO is suppressed and an all-solid-state LiFePO4 /LAO-LLZOF/Li battery stably cycled for 5500 cycles at 3 C. This work reveals the chemistry of Li2 CO3 at the LLZO GBs during cycling, presents a novel lithium penetration mechanism within garnet electrolytes, and provides an innovative method to simultaneously regulate the ion and electron transport at the GBs in garnet electrodes for advanced ASLMBs.

20.
Adv Mater ; 34(12): e2108947, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34994990

RESUMO

High-nickel (Ni ≥ 90%) cathodes with high specific capacity hold great potential for next-generation lithium-ion batteries (LIBs). However, their practical application is restricted by the high interfacial reactivity under continuous air erosion and electrolyte assault. Herein, a stable high-nickel cathode is rationally designed via in situ induction of a dense amorphous Li2 CO3 on the particle surface by a preemptive atmosphere control. Among the residual lithium compounds, Li2 CO3 is the most thermodynamically stable one, so a dense Li2 CO3 coating layer can serve as a physical protection layer to isolate the cathode from contact with moist air. Furthermore, amorphous Li2 CO3 can be transformed into a robust F-rich cathode electrolyte interphase (CEI) during cycling, which reinforces the cathode's interfacial stability and improves the electrochemical performance. The assembled coin cell with this modified cathode delivers a high discharge capacity of 232.4 mAh g-1 with a superior initial Coulombic efficiency (CE) of 95.1%, and considerable capacity retention of 90.4% after 100 cycles. Furthermore, no slurry gelation occurs during the large-scale electrode fabrication process. This work opens a valuable perspective on the evolution of amorphous Li2 CO3 in LIBs and provides guidance on protecting unstable high-capacity cathodes for energy-storage devices.

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