Lithium Salts Research Articles

Harnessing Free Sulfate Groups in Glycosylation Reactions.

General strategies for synthesizing sulfated oligosaccharides employ the protection of sulfate groups for glycosylation or post-sulfation after the synthesis of oligosaccharides. However, the chemical behavior of free sulfate groups in glycosylation reactions has not been thoroughly studied. We examined several glycosyl donors with free sulfate groups, but neither glycosyl imidates nor thioglycosides achieved products. Conversely, activating 6-sulfated GalNAc donors with either a 2-NTroc group or 2-O-acetyl group using an ortho-hexynylbenzoate group at the anomeric position yielded β-glycosides in good yield. These results indicate that glycosylations with a free sulfate group can be performed and that the neighboring group participation of 2-NHTroc and 2-O-acetyl groups works even with an unprotected sulfate group at 6-position. Ab initio calculations supported the formation of acyloxionium-cation via 2-O-acyl participation. Additionally, glycosylation reactions under various counter cations of the sulfate group, such as Na+, Li+, K+, Ba2+ and pyridinium were examined. Results showed that sodium and lithium salt donors yielded the products in good yield. These results were also supported by ab initio calculations. Practical glycosylation reactions between disaccharide donor-acceptor pairs with free sulfate groups successfully yielded the sulfated tetrasaccharides. This study also discusses how a sodium salt acts as a protecting group during glycosylation.

Investigation of tetrazole- and bistetrazole-based lithium salts as colorants in environmentally friendly pyrotechnics

ABSTRACT Due to the harmful effects of chlorinated combustion products and strontium in currently used red-burning pyrotechnics on human health and the environment, new substitutes have to be found. A promising alternative could be using lithium-salts. While it is a literature-known problem that the generation of a lithium-based red flame color is a challenging task due to the diverse requirements of the Li(0) color species, a promising alternative could be using lithium-heterocycle salts. In this context, nitrogen-rich lithium tetrazole and bistetrazole salts, namely, lithium tetrazolate, lithium 5-aminotetrazolate, dilithium 5,5’-bistetrazolate dihydrate and dilithium 5,5’-bis(tetrazolate-1-oxide) have been investigated as potential replacements. To evaluate the performance of the salts a variety of mixtures were prepared and their pyrotechnic parameters were analyzed. Furthermore, application-specific pyrotechnic clusters and parachute flares were produced and these were also tested for burning time, dominant wavelength, spectral purity and luminous intensity. Observations on the use of lithiated nitrogen-rich salts in pyrotechnic mixtures showed a red color impression, indicating the potential of these mixtures. Further research opportunities can be pursued by refining nitrogen-rich compounds.

A physical perspective on lithium therapy.

Lithium salts have strong medical properties in neurological disorders such as bipolar disorder and lithium-responsive headaches (Pereira da Silva Neto and James Almeida, 2010; Lindner et al., 2023; Silva-Néto et al., 2019). They have recently gathered attention due to their potential preventive effect in viral infections (Ferensztajn-Rochowiak and Rybakowski, 2023; Rybakowski, 2022). Though the therapeutic effect of lithium was documented by Cade in the late 1940s, its underlying mechanism of action is still disputed (Malhi and Outhred, 2016). Acute lithium exposure has an activating effect on excitable organic tissue and organisms, and is highly toxic (Schou, 1957; Butler-Munro et al., 2010; Izsak et al., 2021; Yip and Yeung, 2007). Lithium exposure is associated with a strong metabolic response in the organism, with large changes in phospholipid and cholesterol expression (López-Corcuera et al., 1988; Pettegrew et al., 2001; Aliyazicioğlu et al., 2007). Opposite to acute exposure, this metabolic response alleviates excessive cellular activity (Mertens et al., 2015; Stern et al., 2018; Santos et al., 2021). The presence of lithium ions strongly affects lipid conformation and membrane phase unlike other alkali ions (Hauser and Shipley, 1983), with consequences for membrane permeability, buffer property and excitability. This review investigates how lithium ions affect lipid membrane composition and function, and how lithium response might in fact be the body's attempt to counteract the physical presence of lithium ions at cell level. Ideas for further research in microbiology and drug development are discussed.

Polyunsaturated Fatty Acids from Thamnidium elegans and Mortierella alpina Suppress Prostate Cancer Cell Proliferation and Migration

Thamnidium elegans and Mortierella alpina are two oleaginous fungi that belong to Mucoromycota that synthesize polyunsaturated fatty acids, which are credited with multiple health benefits and possible anticancer properties. These fungi were cultivated on culture media, with glucose or glycerol as a carbon source. After extracting the lipids, we transformed them into fatty acid lithium salts (FALSs), which are water-soluble and absorbable mammalian cells, including DU-145 and PC-3 cancer cells. The two cell lines, both long-established prostate cancer models, were treated with FALSs and indicated increased susceptibility to the lipid derivatives. The viability and proliferation rates were significantly reduced, as well as their migratory capabilities, which were significantly impaired compared to olive oil-derived FALS, which was used as a control substance. We conclude that the FALS derivatives of microbial lipids from these organisms exhibit anticancer effects, by suppressing the proliferation and migration of human prostate cancer cell lines.

Inhibition of Kornblum Reaction with Lithium Salts in SN2 Reactions of Sulfonates and a Nucleophile Containing a Pyridine N-Oxide Moiety: Convergent and Selective Synthesis of an MRGPRX2 Antagonist.

A critical step in the development of a convergent synthesis of an MRGPRX2 antagonist (1) was the SN2 reaction with a highly functionalized lactamide electrophile and a unique difluoropiperidine nucleophile containing a pyridine N-oxide moiety. Initial reactions with sulfonate leaving groups exhibited superb stereoselectivity, but yields were very low due to side reactions originated from competitive Kornblum reactions of the pyridine N-oxide and the sulfonates. Markedly improved reaction profiles were achieved by including stoichiometric lithium triflate. NMR data provided insights into how the lithium cation impacted the pyridine N-oxide through coordination and attenuating its nucleophilicity, leading to the inhibition of the undesired Kornblum reactions. Our approach is highly relevant to preservation of the N-oxide, a structural motif known to several marketed products and emerging as an important class in drug discovery in nucleophilic substitutions. Application of this method enabled the production of the target (1 and its HCl salt 1a) up to multikilogram scale with high selectivity and in much improved yield.

Perfluoropolyether-terminated Single-ion Polymer for Enhancing Performance of PEO-based Solid Polymer Electrolyte.

Solid-state electrolytes are receiving increasing attention in lithium metal batteries due to the advantage of high energy density. Poly(ethylene oxide) (PEO) electrolyte possesses good compatibility with lithium salts. However, PEO suffers from a low lithium-ion transference number and poor high-voltage resistance, which significantly hinder its application in lithium metal batteries. Herein, a perfluoropolyether-terminated single-ion polymer (PFPE-polymer) is designed and synthesized in this contribution. By incorporating the PFPE-polymer and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) into PEO via casting, the polymer electrolyte (PFPE-SE) is successfully prepared. Compared to PEO-based electrolytes, PFPE-SE forms a solid electrolyte interface (SEI) layer and inhibits the growth of lithium dendrites on the anode. At 70°C, the lithium-ion transference number and the electrochemical window reach 0.72 and 4.7V, respectively. When tested at a discharge rate of 0.5 C, the Li|PFPE-SE|LFP cell exhibits a specific capacity of 156.0 mAh g-1, with a capacity retention of 74.3% after 230 cycles, superiority the performance of the electrolyte prepared by mixing PEO with LiTFSI. This work presents a promising polymer electrolyte strategy for achieving high-performance lithium metal batteries, leveraging the in situ construction of the SEI layer and the utilization of a single-ion polymer.

1,8-Diazabicyclo[5.4.0]undec-7-ene as Cyclic Ether Electrolyte Polymerization Inhibition for Wide-Temperature-Range High-Rate Lithium-ion Batteries.

1,3-Dioxolane (DOL), with its broad liquid phase temperature window and low Li+-solvent binding energy, stands out as an ideal solvent candidate for the wide-temperature and high-rate electrolytes. Unfortunately, DOL is susceptible to undergo ring-opening polymerization under common lithium salts, which markedly retards the reaction kinetics. This work introduces the organic basic additive 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) to effectively suppress the polymerization, thus achieving compatibility between LiFSI, LiDFOB lithium salts, and DOL. Furthermore, density functional theory (DFT) calculations are utilized to elucidate the underlying mechanisms of DOL polymerization and to clarify how DBU inhibits its polymerization. The resulting electrolyte, devoid of polymer chain formation, forms a weak solvation structure rich in anions, which demonstrates rapid ion transport kinetics in the bulk electrolyte and excellent electrochemical stability at the electrolyte-electrode interfaces (EEIs) simultaneously. When applied to the LiFePO4||graphite full cell, it exhibits exceptional wide-temperature and high-rate performance, with specific capacities reaching 101.2 mAh g -1 at room temperature (20 C), 36.9 mAh g-1 at -40 °C (0.5 C), and 118.0 mAh g-1 at 60 °C (20 C). This study significantly guides the development of wide-temperature, high-rate electrolytes.

Poly(ionic) Liquid-Enhanced Ion Dynamics in Cellulose-Derived Gel Polymer Electrolytes.

Gel polymer electrolytes (GPEs) are regarded as a promising alternative to conventional electrolytes, combining the advantages of solid and liquid electrolytes. Leveraging the abundance and eco-friendliness of cellulose-based materials, GPEs were produced using methyl cellulose and incorporating various doping agents, either an ionic liquid (1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [Pyr14][TFSI]), its polymeric ionic liquid analogue (Poly(diallyldimethylammonium bis(trifluoromethylsulfonyl)imide) [PDADMA][TFSI]), or an anionically charged backbone polymeric ionic liquid (lithium poly[(4-styrenesulfonyl)(trifluoromethyl(S-trifluoromethylsulfonylimino) sulfonyl) imide] LiP[STFSI]). The ion dynamics and molecular interactions within the GPEs were thoroughly analyzed using Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR), Heteronuclear Overhauser Enhancement Spectroscopy (HOESY), and Pulsed-Field Gradient Nuclear Magnetic Resonance Diffusion (PFG-NMR). Li+ transference numbers (tLi+) were successfully calculated. Our study found that by combining slow-diffusing polymeric ionic liquids (PILs) with fast-diffusing lithium salt, we were able to achieve transference numbers comparable to those of liquid electrolytes, especially with the anionic PIL, LiP[STFSI]. This research highlights the influence of the polymer's nature on lithium-ion transport within GPEs. Additionally, micro supercapacitor (MSC) devices assembled with these GPEs exhibited capacitive behavior. These findings suggest that further optimization of GPE composition could significantly improve their performance, thereby positioning them for application in sustainable and efficient energy storage systems.

Co-Catalyzed Suzuki-Miyaura Coupling of Organoboronic Acids and Alkynyl Chlorides Using Potassium Bicarbonate as Base.

Organoboronic acids, some of the most common and widely used organoboron compounds, have not yet been used in the cobalt-catalyzed cross coupling reactions, despite cobalt demonstrating good reactivity with zinc reagents, Grignard reagents, and metal organoborates that are formed by n-butyl lithium or alkaline metal alkoxide salts and organoboron esters. Herein, a highly efficient and practical cobalt-catalyzed coupling reaction of aryl/alkenyl boronic acids and alkynyl chloride under mild reaction conditions is reported. The advantages of the organoboronic acids, along with a broad functional group compatibility and the reaction's tolerance to moisture and air, enable this reaction to be a synthetically useful protocol for the construction of a C(sp2)-C(sp) bond. Lastly, the synthesis of two natural products and a key intermediate of roxadustat was effectively accomplished using the methodology to construct the critical alkynyl-aryl bond.

Engineering Molecule‐Designed In Situ Polymerization on Al‐Doped Molecular‐Sieve Framework Enables Robust Quasi‐Solid‐State Lithium Batteries

AbstractAchieving fast Li+ transport kinetics and stable electrode/electrolyte interfaces is of paramount importance, yet extremely challenging for the practical success of solid‐state lithium metal batteries, which requires the rational design of the structure and composition of solid‐state electrolytes. Herein, a composite quasi‐solid‐state electrolyte is fabricated through in situ polymerization of a molecule‐designed polymer chain within the functionalized molecular sieve framework (Al‐MCM41). In this design, the robust Brønsted/Lewis acid–base interactions between Al‐MCM41 and TFSI− facilitate the dissociation of lithium salt, leading to a Li+ transference number as high as 0.81. Meanwhile, the well‐ordered mesopores of Al‐MCM41 act as the “reservoir” of the polymer chain, creating continuous ionic migration pathways to offer an excellent Li+ conductivity of 1.09 × 10−3 S cm−1 at 30 °C. Furthermore, the polymer with fluorinated and nitrided functional groups guarantees a dual‐reinforced anode and cathode interface. Such an integrated electrolyte with simultaneous unimpeded Li+ transport and robust interfaces delivers extraordinary capacity retention of 84.6% over 600 cycles at 5 C when coupled with LiFePO4 cathode and remarkable reversible capacity of 129.0 mAh g−1 after 200 cycles with high‐voltage NCM622 cathode. This work provides a significant avenue for enhancing the practical feasibility of solid‐state lithium metal batteries.

Scalable Fabrication of Neuromorphic Devices Using Inkjet Printing for the Deposition of Organic Mixed Ionic‐Electronic Conductor

AbstractRecent advancements in artificial intelligence (AI) have highlighted the critical need for energy‐efficient hardware solutions, especially in edge‐computing applications. However, traditional AI approaches are plagued by significant power consumption. In response, researchers have turned to biomimetic strategies, drawing inspiration from the ion‐mediated operating principle of biological synapses, to develop organic neuromorphic devices as promising alternatives. Organic mixed ionic‐electronic conductor (OMIEC) materials have emerged as particularly noteworthy in this field, due to their potential for enhancing neuromorphic computing capabilities. Together with device performance, it is crucial to select devices that allow fabrication via scalable techniques. This study investigates the fabrication of OMIEC‐based neuromorphic devices using inkjet printing, providing a scalable and material‐efficient approach. Employing a commercially available polymer mixed ionic‐electronic conductor (BTEM‐PPV) and a lithium salt, inkjet‐printed devices exhibit performance comparable to those fabricated via traditional spin‐coating methods. These two‐terminal neuromorphic devices demonstrate functionality analogous to literature‐known devices and demonstrate promising frequency‐dependent short‐term plasticity. Furthermore, comparative studies with previous light‐emitting electrochemical cells (LECs) and neuromorphic OMIEC devices validate the efficacy of inkjet printing as a potential fabrication technique. The findings suggest that inkjet printing is suitable for large‐scale production, offering reproducible and stable fabrication processes. By adopting the OMIEC material system, inkjet printing holds the potential for further enhancing device performance and functionality. Overall, this study underscores the viability of inkjet printing as a scalable fabrication method for OMIEC‐based neuromorphic devices, paving the way for advancements in AI hardware.

MXene Surface Engineering Enabling High‐Performance Solid‐State Lithium Metal Batteries

AbstractSolid polymer electrolytes (SPEs) offer inherent advantages for battery applications, such as high safety and excellent processability, but their practical use is limited by challenges like low ionic conductivity, subpar mechanical properties, and instability of the electrode/electrolyte interface. Here, novel SPEs are developed by embedding 2D MXenes decorated at the surface with methoxypolyethylene glycol chains into poly(vinylidene fluoride)‐hexafluoropropylene matrices, enhanced with succinonitrile as a plasticizer. This innovative design improves the compatibility of the modified MXene in poly(vinylidene fluoride)‐hexafluoropropylene and, together with the synergistic effects of succinonitrile, promotes the dissociation of lithium salt. The SPE achieves ionic conductivity of 1.49 × 10−4 S cm−1 at 30 °C, and a Li‐ion transference number of 0.59. These results are supported by comprehensive experimental characterization, COMSOL simulations, and DFT calculations. This SPE enables stable and reversible Li plating/stripping for over 2100 h in Li/Li symmetric cells, while fabricated Li/LiFePO4 full cells deliver a notable capacity of 135.4 mAh g−1 with an average Coulombic efficiency of 98.9% after 100 cycles at 0.2 C. Furthermore, the Li/LiNi0.6Co0.2Mn0.2O2 full cells also demonstrate a capacity of 140.5 mAh g−1 after over 200 cycles at 0.5 C, showcasing an impressive capacity retention rate of 99.6%.

Highly concentrated solution of lithium chloride in organic solvents with heteroditopic receptors

Abstract The solubilization and selective extraction of lithium salts, in particular lithium chloride, in organic solvents have recently attracted attention due to the application in industry. A heteroditopic receptor 1b, which has ether oxygens and 2 urea moieties as cation and anion recognition sites, respectively, cooperatively associates with LiCl in organic solvents. The selective solid–liquid extraction of LiCl and LiBr was observed by 1H NMR in CDCl3 and MeCN-d3. It is possible to prepare highly concentrated solutions of 1b and LiCl in MeCN up to a concentration of 9.6 M, and these solutions exhibit properties similar to those of ionic liquids.

Research Progress on the Activity Stimulation of Lithium Slag in Concrete

Lithium slag (LS), an industrial waste byproduct generated during lithium salt production, is characterized by its harmful trace elements, significant stockpiles and low pozzolanic activity. By 2003, the annual discharge of lithium slag in China surpassed 15 million tons, creating an urgent need for established large-scale disposal technologies. One of the primary strategies for the effective utilization of LS is its application as an auxiliary cementitious material in concrete. However, the low reactivity of LS and challenges associated with its large-scale application impede its effective utilization. Enhancing the pozzolanic activity of LS is pivotal for its substantial incorporation into concrete. This study begins by analyzing the physicochemical properties and volcanic ash reactivity of LS derived from various lithium extraction techniques. It subsequently explores the diverse activation techniques aimed at improving the reactivity of LS within concrete. Ultimately, this paper highlights the significance of synergistic activation strategies, particularly physicochemical co-excitation and multi-exciter composite excitation. These approaches are identified as critical pathways for enhancing the activity of LS. Through this exploration, this study aims to unveil innovative strategies that bolster the resource utilization efficiency of LS, thereby facilitating its effective application in the concrete domain.

Outer Helmholtz plane adsorption regulation to achieve low-concentration of pure propylene carbonate solvent electrolytes compatible with graphite anode

The low melting point and high polarity of propylene carbonate (PC) make it an ideal solvent for electrolytes of lithium-ion batteries (LIBs), but the incompatibility with graphite anode hinders the application. In the present study, a new method is developed to solve this problem from a new viewpoint. Introduction of saturated LiNO3 (0.14 mol L‒1) into pure PC electrolyte containing lithium salt with normal concentration (1.38 mol L‒1) leads to a perfect compatibility with graphite anode. Li/Graphite cell using this pure PC electrolyte shows a reversible capacity of 350.0 mAh g‒1 and a 200-cycle capacity retention of 96.3 %. Further mechanism study and theoretical computation indicate that the NO3‒ anions are adsorbed to outer Helmholtz plane of the electric double layer at the graphite anode interface. This changes the Li+ solvation structure in the electric double layer, facilitating the Li+ desolvation process hence resulting in high compatibility with the graphite anode. The most prominent advantage of the present strategy is that, because of the adsorption of NO3‒ anions to the outer Helmholtz plane, the compatibility with graphite anode could be improved by introduction of tiny amount of Li salt without large change of the bulk phase properties of the electrolyte. This work provides a new understanding of the compatibility from the viewpoint of outer Helmholtz plane, which might deliver new insights for the optimization of electrolytes for LIBs.

Polymer electrolytes based on PEO and lithium tetraalkoxyborate salts with ionic liquid properties for lithium-based batteries

The development of lithium-ion batteries (LIBs) with improved safety features is crucial due to the inherent risks associated with liquid electrolytes, such as fires, explosions, and leakage. This study explores the potential of solid polymer electrolytes (SPEs) based on poly(ethylene oxide) (PEO) and lithium tetraalkoxyborate salts (LiTAB) with ionic liquid properties as a safer alternative. Ionic liquids (ILs) are examined for their high ionic conductivity, wide electrochemical window, and excellent thermal stability, despite their high synthesis costs and viscosity challenges. The study proposes the use of a novel LiTAB salt with an oligomeric star-shaped anion structure that reduces mobility, enhancing lithium ion transference numbers. This IL serves as both a lithium salt and an active plasticizer in PEO-based SPEs, offering potential for 3D printing applications. Experimental results demonstrate that these electrolytes exhibit favorable rheological properties, high ionic conductivities, and significant lithium ion transference numbers, addressing the key limitations of conventional PEO-based electrolytes. The findings suggest that incorporating these LiTAB salts in SPEs could significantly enhance the safety and performance of LIBs, particularly for applications in miniaturized consumer electronics and electronic implants.

Ternary-salt localized high-concentration electrolyte: An ideal companion facilitating stable high-voltage cycling of lithium metal batteries

The strategic design of novel electrolytes to further enhance the overall performance of lithium metal batteries (LMBs) is highly desirable. Herein, combining the synergistic effect of multiple functional lithium (Li) salts and the solvation structure advantage of localized high-concentration electrolyte (LHCE), we propose a novel ternary-salt localized high-concentration electrolyte (TSLHCE) termed CETHER3-TDE that achieves broad electrochemical stability window, dendrite-free Li deposition, effective electrode interface protection, flame retardancy, and significantly enhances the cycling performance of LMBs. CETHER3-TDE enables Li (50 μm thickness) ||NMC622 (13.8 mg cm−2, 2.50 mAh cm−2) cell to achieve an impressive capacity retention of 83 % after 300 cycles with a cut-off voltage of 4.4 V. Additionally, it enables the Li (50 μm thickness) ||NMC811 (19.8 mg cm−2, 3.96 mAh cm−2) cell to achieve a capacity retention of 83.6 % after 170 cycles, under an ultrahigh cut-off voltage of 4.6 V. Furthermore, the Li metal pouch cell employing CETHER3-TDE, featuring a low negative/positive (N/P) capacity ratio of 1.33 and lean electrolytes of 2.3gAh−1, attains an energy density of 413 Wh kg−1 and maintains stable cycling at 4.6 V. Moreover, analysis conducted by Accelerating Rate Calorimeter has verified that CETHER3-TDE enhances both the thermal stability as well as the thermal runaway trigger temperature of LMBs, thereby substantially improving their safety. This work provides valuable insights for future research on multi-salt complex electrolyte system for practical application in high-energy-density and high safety LMBs.

Ladder electrodialysis: Efficient up-concentration of lithium ion and its mechanisms behind

The development of lithium extraction technology from salt lakes has seen significant demand in recent years, driven by the surge in energy storage needs for lithium-ion batteries used in electric vehicles and renewable power plants. Currently, evaporation technologies such as Mechanical Vapor Recompression (MVR) and Multi-Effect Distillation (MED) are commonly employed to concentrate lithium chloride for subsequent lithium carbonate precipitation. However, these evaporation methods limit lithium yield and increase capital and operational costs, particularly in high latitude areas. Pressure-driven membrane processes like reverse osmosis are hindered by concentration polarization and cannot significantly increase lithium chloride concentration. This study proposes a new membrane stack configuration with a laddered compartment design, termed Ladder Electrodialysis (LED), which addresses the concentration polarization issue and achieves a lithium salt (LiCl) concentration of 16.39 % (196 g·L−1). Economic analysis shows that the energy consumption is only 0.42 kWh per kilogram of LiCl. Ladder electrodialysis is a novel salt concentration technology, with applications in brine valorization or disposal.

Photoexcitation‐Enhanced High‐Ionic Conductivity in Polymer Electrolytes for Flexible, All‐Solid‐State Lithium‐Metal Batteries Operating at Room Temperature

Designing solid polymer electrolytes (SPEs) with high ionic conductivity for room‐temperature operation is essential for advancing flexible all‐solid‐state energy storage devices. Innovative strategies are urgently required to develop SPEs that are safe, stable, and high‐performing. In this work, we introduce photoexcitation‐modulated heterojunctions as catalytically active fillers within SPEs, guided by photocatalytic design principles, and employ natural bacterial cellulose to enhance the mechanical properties of the inorganic‐filled SPEs. In‐situ photothermal experiments and theoretical calculations reveal that the strong photogenerated electric field produced by trace heterojunctions within poly(ethylene oxide) electrolytes under photoexcitation significantly enhances lithium salt dissociation, increasing the concentration of mobile Li+. This results in a substantial increase in ionic conductivity, reaching 0.135 mS cm−1 at 25 °C, with a Li+ transference number as high as 0.46. The flexible all‐solid‐state lithium‐metal pouch cells exhibit an impressive discharge capacity of 178.8 mAh g−1 even after repeated bending and folding, and demonstrate exceptional long‐term cycling stability, retaining 86.7% of their initial capacity after 250 cycles at 1 C (25 °C). This research offers a novel approach to developing high‐performance flexible lithium‐metal batteries.

Synthesis of Monodisperse and Discrete Ultra-High Nickel LiNi0.97Co0.02Mn0.01O2 Octahedral Single Crystals via Single Crystal Intermediates for Li-Ion Batteries.

Micrometer-sized single crystal cathodes have garnered significant interest as promising cathode materials for lithium-ion batteries due to their ability to reduce surface area exposure to electrolytes and suppress side reactions, thereby enhancing electrochemical performance. One of the challenging issues with single crystal cathode materials is synthesizing monodisperse and discrete single crystals rather than agglomerated quasi-single crystals. However, conventional solid-state synthesis of most single crystals results in severe agglomeration and cation mixing, as it requires high temperatures to promote particle growth to several micrometers. In this study, a novel morphology-conserving reaction strategy that employs octahedron single crystal intermediates is introduced to synthesize discrete, monodisperse LiNi0.97Co0.02Mn0.01O2 octahedron single crystals. This scalable and cost-effective approach involves using rock-salt Ni0.97Co0.02Mn0.01O1+x octahedrons as single crystal intermediates, which are transformed in unreactive unary lithium salt melts (LiCl and Li2SO4) from spherical Ni0.97Co0.02Mn0.01(OH)2 obtained via coprecipitation. These intermediates are then subjected to a stoichiometric amount of Li precursor in a conventional solid-state synthesis to produce layered LiNi0.97Co0.02Mn0.01O2. This process is a morphology-conserving lithiation reaction, leading to the formation of discrete and monodisperse LiNi0.97Co0.02Mn0.01O2 octahedron single crystals. The resultant LiNi0.97Co0.02Mn0.01O2 single crystals demonstrate superior electrochemical performance, including stable capacity retention over 150 cycles, which surpasses that of typical quasi-single crystals produced through conventional methods. This is attributed to negligible crack formation during cycling, in contrast to significant cracking observed in conventional quasi-single crystals. This implies that single-crystal forms are preferred over agglomerated quasi-single crystal forms for enhancing cycle performance. These findings provide valuable insights into the industrial synthesis of discrete and monodisperse ultrahigh-nickel oxide cathode materials.