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Due to its high thermal stability, environmental friendliness, and safety, lithium phosphate (Li3PO4) is used as a solid electrolyte in battery applications, but it is usually used with dopants due to its lower ionic conductivity, which is required for ion transport. However, due to its stability and environmentally friendly aspect, lithium phosphate is still a hot topic among suitable energy materials that need further research to improve its electrochemical properties. In the current work, a novel synthesis of lithium phosphate was proposed from the raw materials lithium carbonate (Li2CO3) and trisodium phosphate dodecahydrate (Na3PO4*12H2O) under suitable stoichiometric conditions using the co-precipitation method. In the set of synthesized samples, a single-phase β-Li3PO4 (named LPO-4) with 99.7% purity and 93.49% yield was successfully prepared under appropriate stoichiometric conditions and pH 13 at 90 °C. The average particle size was 10 nm with a large surface area of 9.02 m2g−1. Electrochemical impedance spectroscopy (EIS) of LPO-4 revealed a conductivity of 7.1 × 10−6 S.cm−1 at room temperature and 2.7 × 10−5 S.cm−1 at 80 °C with a low activation energy of 0.38 eV. This performance is attributed to the morphology of the nanotubes and the smaller particle size, which enlarge the reaction interfaces and shorten the diffusion distance of lithium ions. The kinetic and thermodynamic key parameters showed that the β-Li3PO4 exhibits thermal stability in the room temperature range up to 208.8 °C. All these property values indicate a promising application of lithium phosphate as a solid electrolyte in solid-state batteries and a new route for further investigation. [ABSTRACT FROM AUTHOR]

[Display omitted] • PO 4 3−-doping and Li 3 PO 4 -coating of dual modification of LiNiO 2 are achieved. • PO 4 3− doping improves the reversibility of crystal structure. • PO 4 3− doping induces surface structural transformation of the material. • Li 3 PO 4 coating could ameliorate the interface stability. Lithium nickel oxide (LiNiO 2) cathode materials are featured with high capacity and low cost for rechargeable lithium-ion batteries but suffer from severe structure and interface instability. Bulk doping together with surface coating has been proven to be an efficient approach to improve the inner structure and interfacial stability of the LiNiO 2 cathode material. Nevertheless, the role of anion doping seems to be quite different from that of cation doping, and a deep insight will be desirable for the structure design of the LiNiO 2 cathode material. In this paper, PO 4 3−-doped and Li 3 PO 4 -coating of dual modification of LiNiO 2 are achieved via a facile approach. It is demonstrated that the PO 4 3− anions are doped into the tetrahedron vacant sites of the crystal structure, alleviating the phase transition and improving the reversibility of crystal structure. Besides, the Li 3 PO 4 coating layer ameliorates the interface stability to restrain the side reactions. Therefore, the dual modification enhances overall structural stability of the material to provide excellent performance. Moreover, the consumption of the Li residues by the formation of Li 3 PO 4 coating layer, and the enlarged interlayer spacing of the crystal structure by PO 4 3− doping can facilitate the Li+ ions diffusion, resulting in a superior rate capability. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium batteries (ASSLBs) are promising energy‐storage devices with high energy density and safety. However, the discharge capacity of ASSLBs that use sulfide solid electrolytes (SEs) and Ni‐rich cathode active materials (CAMs) deteriorates significantly during electrochemical cycling. Interfacial coatings between CAM and sulfide SEs are known to effectively alleviate capacity deterioration. Among the various coating materials, lithium phosphate (LPO) was selected and synthesized via atomic layer deposition (ALD). The crystal phase of the LPO thin film irreversibly changed, and the Li‐ion conductivity deteriorated after heat treatment. Additionally, particle ALD (P‐ALD) of LPO was successfully performed to completely passivate the CAM particles. Torque cells with the LPO‐coated CAMs showed excellent capacity retention, whereas the cells without the LPO coating showed a significantly deteriorated discharge capacity with increased internal resistances. The passivation effect of the LPO coating was confirmed by the cross‐sectional images from a FIB and scanning electron microscopy with energy‐dispersive X‐ray spectroscopy (SEM–EDS) dual system. We believe that the study will help us investigate the effects of side reactions between sulfide SEs and CAMs on the performance and stability of P‐ALD. [ABSTRACT FROM AUTHOR]

Doping and particle size controlling are two important approaches to improve the electrochemical performance of LiMn x Fe 1−x PO 4 cathode materials. By employing a straightforward hydrothermal method and utilizing cost-effective lithium phosphate (Li 3 PO 4) as the precursor, we successfully synthesized high Mn-content LiMn 0.79 Fe 0.2 Mg 0.01 PO 4 /C composites. The results reveal that the minute amount of Mg substantially enhances the electrochemical performance. In the subsequent mechanism study using Li 3 PO 4 precursors with different particle size, we found that the nucleation process, dependent on specific surface area and diffusion rate, is likely to play a critical role for the size and morphology of formed LiMn 0.79 Fe 0.2 Mg 0.01 PO 4. LiMn 0.79 Fe 0.2 Mg 0.01 PO 4 /C (LMFP-1), synthesized from initially smaller-sized and less agglomerated Li 3 PO 4 (LPO-1), exhibited the most diminutive average particle size coupled with the highest specific surface area, which further facilitated electrolyte interfacial interaction and promoted Li+ diffusion kinetics. At 1C, LMFP-1 displayed a specific capacity of 110.7 mAh g−1, with 97.07% capacity retention after 200 cycles. This study provides pivotal insights for the synthesis of high-performance LiMn x Fe 1−x PO 4 materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Due to its high thermal stability, environmental friendliness, and safety, lithium phosphate (Li3PO4) is used as a solid electrolyte in battery applications, but it is usually used with dopants due to its lower ionic conductivity, which is required for ion transport. However, due to its stability and environmentally friendly aspect, lithium phosphate is still a hot topic among suitable energy materials that need further research to improve its electrochemical properties. In the current work, a novel synthesis of lithium phosphate was proposed from the raw materials lithium carbonate (Li2CO3) and trisodium phosphate dodecahydrate (Na3PO4*12H2O) under suitable stoichiometric conditions using the co-precipitation method. In the set of synthesized samples, a single-phase β-Li3PO4 (named LPO-4) with 99.7% purity and 93.49% yield was successfully prepared under appropriate stoichiometric conditions and pH 13 at 90 °C. The average particle size was 10 nm with a large surface area of 9.02 m2g−1. Electrochemical impedance spectroscopy (EIS) of LPO-4 revealed a conductivity of 7.1 × 10−6 S.cm−1 at room temperature and 2.7 × 10−5 S.cm−1 at 80 °C with a low activation energy of 0.38 eV. This performance is attributed to the morphology of the nanotubes and the smaller particle size, which enlarge the reaction interfaces and shorten the diffusion distance of lithium ions. The kinetic and thermodynamic key parameters showed that the β-Li3PO4 exhibits thermal stability in the room temperature range up to 208.8 °C. All these property values indicate a promising application of lithium phosphate as a solid electrolyte in solid-state batteries and a new route for further investigation.

In this study, we investigated the influence of post-deposition annealing (PDA) process on lithium phosphate (Li3PO4) solid-state thin films on silicon carbide (SiC) substrate in terms of materials and electrical properties. Li3PO4 thin films were deposited through radio frequency (RF) sputtering and post-deposition annealing was performed in a temperature range of 200–400 °C. The Li3PO4 thin films show typical amorphous structures, and no changes are observed even after 400 °C PDA process. The Li 1 s/P 2p ratio varies with changing the annealing temperature and the highest Li is detected under 300 °C annealing, where the ionic conductivity increases to 1.00 × 10−4 S/mm at the same temperature. The rectification ratio of the 300 °C annealed device is obtained as 1.45 × 103, which is 23 times higher value than as-deposited Li3PO4/SiC device without annealing. This result suggests that the delicate control of Li3PO4 deposition could provide a significant enhancement on the electrical devices and the solid electrolyte batteries.

Most solid electrolyte materials have not shown enough conductivity to be used as an electrolyte for a battery in electronic devices. The mixture of 1.5 Li2O and P2O5 has been reported to show a good conductivity higher than that of Li3PO4, which is thought to be due to phase mixtures that are formed during manufacturing process. Montmorillonite (MMT) was used to explore the effect of phase mixture on conductivity of new 1.5Li2O-P2O5-MMT solid electrolyte composite, which was prepared through conventional solid-state reaction procedures. This study was conducted, how the addition of MMT affects process of forming 1.5Li2O-P2O5-MMT compound, and whether it influences electrical properties and permittivity of compound. Morphology, hygroscopicity, and electrochemical characteristics of this material were analyzed in this study. The shape of glassy-like flakes was reduced in micrographs, and granular lumps were getting larger as MMT was added. Addition also tended to reduce hygroscopicity, as indicated by a reduced rate of porous absorption. Whole Nyquist plot consisted of only one imperfect semicircular arc, indicating only one relaxation process occurred in materials. Capacitance of all arcs indicated main contribution of response was from bulk material. Slope of dielectric loss of samples indicated that conduction in the samples was mainly dominated by dc conduction. MMT clays acted as a medium that absorbed liquid phase in solid-state reaction, increasing formation of dominant phase, which determined total conductivity of compound. Conductivity was higher than that of Li4P2O7, where the sample of 20 wt% MMT addition was most polarizable and most dielectric compound.

This study addresses the improved cycling stability of Li‐ion batteries based on Fe–Ti‐doped LiNi0.5Mn1.5O4 (LNMO) high‐voltage cathode active material and graphite anodes. By using 1 wt% Li3PO4 as cathode additive, over 90% capacity retention for 1000 charge–discharge cycles and remaining capacities of 109 mAh g−1 are reached in a cell with an areal capacity of 2.3 mAh cm−2 (potential range: 3.5–4.9 V). Cells without the additive, in contrast, suffer from accelerated capacity loss and increase polarization, resulting in capacity retention of only 78% over 1000 cycles. An electrolyte consisting of ethylene carbonate, dimethyl carbonate, and LiPF6 is used without additional additives. The significantly improved cycling stability of the full cells is mainly due to two factors, namely, the low MnIII content of the Fe–Ti‐doped LNMO active material and the use of the cathode‐additive Li3PO4. Crystalline Li3PO4 yields a drastic reduction of transition metal deposition on the graphite anode and prevents Li loss and the propagation of cell polarization. Li3PO4 is added to the cathode slurry that makes it a very simple and scalable process, first reported herein. The positive effects of crystalline Li3PO4 as electrode additive, however, should apply to other cell chemistries as well. [ABSTRACT FROM AUTHOR]

This study addresses the improved cycling stability of Li‐ion batteries based on Fe–Ti‐doped LiNi0.5Mn1.5O4 (LNMO) high‐voltage cathode active material and graphite anodes. By using 1 wt% Li3PO4 as cathode additive, over 90% capacity retention for 1000 charge–discharge cycles and remaining capacities of 109 mAh g−1 are reached in a cell with an areal capacity of 2.3 mAh cm−2 (potential range: 3.5–4.9 V). Cells without the additive, in contrast, suffer from accelerated capacity loss and increase polarization, resulting in capacity retention of only 78% over 1000 cycles. An electrolyte consisting of ethylene carbonate, dimethyl carbonate, and LiPF6 is used without additional additives. The significantly improved cycling stability of the full cells is mainly due to two factors, namely, the low MnIII content of the Fe–Ti‐doped LNMO active material and the use of the cathode‐additive Li3PO4. Crystalline Li3PO4 yields a drastic reduction of transition metal deposition on the graphite anode and prevents Li loss and the propagation of cell polarization. Li3PO4 is added to the cathode slurry that makes it a very simple and scalable process, first reported herein. The positive effects of crystalline Li3PO4 as electrode additive, however, should apply to other cell chemistries as well. [ABSTRACT FROM AUTHOR]

Lithium-sulfur (Li-S) batteries are the potential alternative for the lithium-ion batteries, owing to their remarkable energy density and specific capacity. Nevertheless, the lower utilization of active materials and the “shuttle effect” have impeded their widespread commercialization. To address these hurdles, a pioneering method has been proposed, involving a lithium phosphate-incorporated multi-walled carbon nanotube (Li3PO4@MWCNT) interlayer. The Li3PO4@MWCNT interlayer primarily serves as a physical barrier against polysulfide shuttling. Its highly conductive cross-link structure enables it to adsorb chemically derived lithium polysulfides (LiPS) and catalyze their conversion by incorporating Li3PO4 into the MWCNT matrix. This synergistic effect of immobilizing and converting LiPS results in a significant reduction in the “shuttle effect,” leading to enhanced sulfur utilization. The experimental results evidence the enhanced performance of the Li-S cells, with a capacity of 381 mAh g−1 at 0.1C and high C-rate performance of 393 mAh g−1 at 1C.

Background. Lithium salts are obtained mainly from lithium-containing minerals. But since the lithium content in them is extremely low, the actual problem is the search for new raw sources of lithium, among which some natural brines in Uzbekistan attract attention. Purpose: To study the conditions of precipitation of lithium ions by sodium hydrogen phosphate from salt waters on the territory of Uzbekistan. Methodology. Precipitation of lithium ion by sodium hydrogen phosphate from saline waters, determination of interfering factors by conductometry and densitometry. Originality. A method has been developed for the precipitation of lithium ions from brines with sodium hydrogen phosphate at 60-70°C from a mixture of sodium, potassium, and magnesium ions. Findings. It has been established that from 0.3 N (according to sodium and potassium ions) solutions, at temperatures above 35°C, and also above 60°C, lithium ions can precipitate in the form of lithium phosphate. [ABSTRACT FROM AUTHOR]

In this study, deep eutectic solvent synthesized by choline chloride (C5H14CINO) and oxalic acid dihydrate (C2H2O4·2H2O) was used to recycling LiFePO4 cathodes for spent lithium-ion batteries. The recycling process was optimized by response surface methodology. When the solid-to-liquid ratio is 0.02 and the reaction was performed at 106 °C for 110 min, the leaching efficiencies of lithium and iron are 95.3% and 85.2%, respectively. The measurement results show that iron is recycled as the form of FeC2O4·2H2O after the UV irradiation and lithium is recycled by chemical precipitation. No mineral acid or high temperature is involved in this work, which has great environmental significance to promote the healthy development of the battery recycling technology. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Most solid electrolyte materials have not shown enough conductivity to be used as an electrolyte for a battery in electronic devices. The mixture of 1.5 Li2O and P2O5 has been reported to show a good conductivity higher than that of Li3PO4, which is thought to be due to phase mixtures that are formed during manufacturing process. Montmorillonite (MMT) was used to explore the effect of phase mixture on conductivity of new 1.5Li2O-P2O5-MMT solid electrolyte composite, which was prepared through conventional solid-state reaction procedures. This study was conducted, how the addition of MMT affects process of forming 1.5Li2O-P2O5-MMT compound, and whether it influences electrical properties and permittivity of compound. Morphology, hygroscopicity, and electrochemical characteristics of this material were analyzed in this study. The shape of glassy-like flakes was reduced in micrographs, and granular lumps were getting larger as MMT was added. Addition also tended to reduce hygroscopicity, as indicated by a reduced rate of porous absorption. Whole Nyquist plot consisted of only one imperfect semicircular arc, indicating only one relaxation process occurred in materials. Capacitance of all arcs indicated main contribution of response was from bulk material. Slope of dielectric loss of samples indicated that conduction in the samples was mainly dominated by dc conduction. MMT clays acted as a medium that absorbed liquid phase in solid-state reaction, increasing formation of dominant phase, which determined total conductivity of compound. Conductivity was higher than that of Li4P2O7, where the sample of 20 wt% MMT addition was most polarizable and most dielectric compound. [ABSTRACT FROM AUTHOR]

Carrier selective contacts with passivation effects are considered to have a significant influence on the performance of crystalline silicon (c-Si) solar cells. It is essential for electron selective contact materials to meet the requirements of ultra-low contact resistance and excellent passivation effects. This work introduces a stack layer of Lithium Phosphate (Li 3 PO 4 ) /Titanium Dioxide (TiO 2 ) as a new electron selective passivating contact. It is found that the stack achieves an impressive contact resistivity (ρ c ) of 0.128 mΩ cm 2 on n-type c-Si substrates with resistivity ranging from 1 to 3 Ω cm (14.6 mΩ cm 2 for the n-Si/a-Si:H/Li 3 PO 4 /TiO 2 /Al contact). Furthermore, it effectively reduces the surface recombination parameter (J 0 ) to less than 4 fA by incorporating a 6 nm a-Si:H(i) layer. The characterization of the n-Si/Li 3 PO 4 /TiO 2 interface reveals that phosphorus diffusion into silicon plays a crucial role in achieving the ultra-low contact resistivity, while the presence of PO 4 3- groups helps in fixing hydrogen atoms to maintain the desired chemical passivation effect. Finally, a silicon heterojunction solar cell (SHJ) with a rear full-area configuration of a-Si:H/Li 3 PO 4 /TiO 2 /Al is successfully demonstrated achieving an impressive power conversion efficiency of 22.89%. The result proves the efficacy of employing hydrogen-rich low-work function metal oxide stacks as electron selective passivating contacts., (© 2024 Wiley‐VCH GmbH.)

Lithium was studied to precipitate into Li3PO4 by adding Na3PO4 under various experimental conditions such as initial lithium concentration of the solution, initial pH of the solution, temperature, and the mol equivalent ratio of Na3PO4. The precipitation mechanism of Li3PO4 was investigated with the change of pH value of the solution over time. The precipitation efficiency of Li3PO4 was 95.4% in the condition of the mol equivalent ratio of Na3PO4 of 1, initial Li concentration of 7 g/L, initial pH of 9.5, and at 90°C. When Na3PO4 was added three times, divided in the mol equivalent ratio of 1 via the hydrolysis reaction of PO43−, which inhibits the Li3PO4 precipitation reaction, an excellent precipitation efficiency of 98.4% was obtained. Co‐precipitated Na2HPO4 with Li3PO4 was washed by distilled water in the condition of solid/liquid ratio of 10% and at 90°C. The purity of the final Li3PO4 product was found to be 99.1%. [ABSTRACT FROM AUTHOR]

We successfully prepared single-phase sample of the low-temperature β-type form of lithium phosphate Li3PO4 by a stoichiometric mixing of LiOH solution and NH4H2PO4 powder at room temperature without heating. The orthorhombic lattice parameters with the space group of Pmn21 for β-Li3PO4 were refined to be a = 6.1281(6) Å, b = 5.2674(5) Å, c = 4.8923(2) Å, and V = 157.92(2) Å3. We also prepared the single-phase sample of high-temperature γ-Li3PO4 by heating the β-Li3PO4 at 650°C. The orthorhombic lattice parameters with the space group of Pmnb for γ-Li3PO4 were refined to be a = 6.12569(5) Å, b = 10.48730(9) Å, c = 4.92957(4) Å, and V = 316.685(4) Å3. The structure transformation from β- to γ-type phase was examined utilizing the XRD measurements. The XRD data confirmed the continuous phase change in the temperature range between 25°C and 650°C. The lattice contraction for the β-Li3PO4 phase was observed between 150°C and 350°C. The phase transformation from β- to γ-Li3PO4 was observed around 450°C. The spherical primary particle size was ca. 20–30 nm order for both β- and γ-Li3PO4 samples. Accordingly, the nano-sized particle Li3PO4 sample can be easily prepared using the present synthetic technique at room temperature.

Glass composition based on (LiF 50 mol%–P2O5 50 mol%) with increasing concentrations of MnO2 (0.25–2.0 mol%) dopants were synthesized. The prepared glasses were characterized by optical, Fourier transform infrared (FTIR) and photoluminescence (PL) spectral analysis. Optical absorption measurements indicate the absorption of divalent Mn2+ ions that is identified only at high percent due to spin-forbidden action for the absorption of them. FTIR spectra reveal characteristic phosphate group vibrations as it is assumed that some LiF4 units are formed beside (PO3F) groups. Photoluminescence spectra reveal characteristic emission and excitation peaks for divalent manganese ions in octahedral coordination which create the red light emission. The intensity of red luminescence is increased by MnO2 content increase. The measurements after gamma irradiation indicate the stability of the studied host glass, the formed divalent manganese ions are stable towards irradiation and remain in octahedral coordination. The alteration values of the optical parameters are related to the structural changes in parallel increasing MnO2 content and gamma-irradiation. [ABSTRACT FROM AUTHOR]

Li-Rich cathode materials are a very promising cathode material for lithium-ion batteries due to its high energy density and low cost, and being environmentally friendly. However, there will be some defects such as lower initial coulomb efficiency, poor cycle stability, and poor rate performance that make the material difficult to commercialize so far. In this paper, we use Li1.2Mn0.54Ni0.13Co0.13O2 (LMNC) as the raw cathode material, lithium phosphate (Li3PO4) and polyaniline (PANI) are constructed as surface modifiers of LMNC, and the electrochemical performance of the modified material has been significantly improved. Compared with the raw material, the initial coulomb efficiency is increased from 64.5 to 82.3%. After 100 cycles at 1C, the capacity retention rate reaches 94.1% (raw material is 81.3%) and the specific capacity can reach 109.57 mAh g−1 under the high current density of 5C (raw material is 73.27 mAh g−1). As a result, the hybrid coating layer not only can be used as a protective layer to protect electrode materials from HF corrosion, but also has excellent electrical conductivity to promote the exchange of ions and electrons. [ABSTRACT FROM AUTHOR]

An organic lithium cyclophosphate named lithium 1, 3, 2-dioxaphosphinan-2-olate 2-oxide (LiDOP) was designed and synthesized as cathode electrolyte interface forming-film additive. It can undergo ring-opening polymerization during charging and form an organic–inorganic hybrid polymers on the cathode surface with alternately connected –LiPO 4 and –(CH 2) 3 –. The LiDOP-derived CEI film possesses high ionic conductivity, flexibility and mechanical strength. [Display omitted] • Designed and synthesized an air-stable cyclophosphate Li salt as electrolyte additive. • The synthesized Li salt can be preferentially oxidized and form an organic–inorganic hybrid polymer on the cathode surface with –LiPO 4 and –(CH 2) 3 – alternately connected. • The formed CEI film possess a higher ionic conductivity and mechanical strength than conventional organic or inorganic-based CEI film. • Being able to enhance the rate performance (5C) and long-term cycling performance under 4.8 V for high-voltage lithium-ion batteries. The structural stability and ionic conductivity of the cathode electrolyte interface (CEI) film at high voltages are crucial to the nickel-rich layered cathode in Li-ion batteries (LIBs). These characteristics are largely determined by electrolyte components. Herein, an air-stable organic cyclophosphate salt named lithium 1, 3, 2-dioxaphosphinan-2-olate-2-oxide (LiDOP) is designed and synthesized as a CEI forming additive. It preferentially oxidizes and undergoes opening-ring polymerization under charging to form an organic–inorganic hybrid polymers with –LiPO 4 segments and –(CH 2) 3 – alternately connected on the cathode surface. Such a structure endows CEI film with high ionic conductivity, flexibility and mechanical strength, which can ameliorate the structure phase transformation, suppress the transition metal ion dissolution and enhance the interfacial stability at high cut-off voltage. The electrolyte with 0.2 wt% LiDOP endows 4.3 V-charged Li||LiNi 0.8 Co 0.1 Mn 0.1 O 2 battery with 83.2 % capacity retention after 200 cycles at 5C rate. The graphite||NCM811 pouch cell shows a capacity retention of 85.6 % after 150 cycles under a 4.5 V voltage, while the cell without LiDOP shows only 23.5 %. Our work demonstrates the effectiveness of covalently coupled P-O-Li compounds as CEI film in stabilizing the interface, which provides a guidance for the electrolyte design in high-voltage LIBs. [ABSTRACT FROM AUTHOR]

Surface deterioration occurs more easily in nickel-rich cathode materials with the increase of nickel content. To simultaneously prevent deterioration of active cathode materials and improve the electrochemical performance of the nickel-rich cathode material, the surface of nickel-rich LiNi0.6Co0.2Mn0.2O2 cathode material is decorated with the stable structure and conductive Li3PO4 by a facile method. The LiNi0.6Co0.2Mn0.2O2-1wt%, 2wt%, 3wt%Li3PO4 samples deliver a high-capacity retention of more than 85% after 100 cycles at 1 C under a high voltage of 4.5 V. The effect of different coating amounts (0–5wt%) for the LiNi0.6Co0.2Mn0.2O2 cathode is analyzed in detail. Results show that 2wt% coating of Li3PO4 gives better performance compared to other coating concentrations. Detailed analysis of the structure of the samples during the charge-discharge process is performed by in-situ X-ray diffraction. It is indicated that the modification for LiNi0.6Co0.2Mn0.2O2 cathode could protect the well-layered structure under high voltages. In consequence, the electrochemical performance of modified samples is greatly improved. [ABSTRACT FROM AUTHOR]

We successfully prepared single-phase sample of the low-temperature β-type form of lithium phosphate Li3PO4 by a stoichiometric mixing of LiOH solution and NH4H2PO4 powder at room temperature without heating. The orthorhombic lattice parameters with the space group of Pmn21 for β-Li3PO4 were refined to be a = 6.1281(6) Å, b = 5.2674(5) Å, c = 4.8923(2) Å, and V = 157.92(2) Å3. We also prepared the single-phase sample of high-temperature γ-Li3PO4 by heating the β-Li3PO4 at 650°C. The orthorhombic lattice parameters with the space group of Pmnb for γ-Li3PO4 were refined to be a = 6.12569(5) Å, b = 10.48730(9) Å, c = 4.92957(4) Å, and V = 316.685(4) Å3. The structure transformation from β- to γ-type phase was examined utilizing the XRD measurements. The XRD data confirmed the continuous phase change in the temperature range between 25°C and 650°C. The lattice contraction for the β-Li3PO4 phase was observed between 150°C and 350°C. The phase transformation from β- to γ-Li3PO4 was observed around 450°C. The spherical primary particle size was ca. 20–30 nm order for both β- and γ-Li3PO4 samples. Accordingly, the nano-sized particle Li3PO4 sample can be easily prepared using the present synthetic technique at room temperature. [ABSTRACT FROM AUTHOR]

Lithium phosphate (Li3PO4) is a well-known solid electrolyte for lithium-ions. In this study, we analyzed the effects of Li3PO4 coating on the electrochemical performance of LiNi0.6Co0.2Mn0.2O2 (NCM), a nickel-rich cathode. In particular, the coated materials exhibited enhanced cycle stability at high voltages and possessed superior rate capability. Among the cathodes with different coating levels (0.5–3 wt%), the one with 2 wt% of Li3PO4 provided the best rate capability, possibly because it is a moderate coating level at which the formation of an excessive cathode electrolyte interface (CEI) is suppressed. Thus, an optimal coating was achieved such that the inhibition in the ionic conduction by the excessive CEI is avoided, while the thickness of the coating layer, which can hinder the ionic transport as well, is minimal. The coated NCM effectively suppressed the formation of CEI, especially LiOH component with insulating nature, as revealed by X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy. As a result, the coated NCM retained more than 70% of the relative capacity, while pristine NCM retained only 35.1% relative capacity after cycling at 3.0–4.9 V vs. Li/Li+ for 200 cycles. This study demonstrates that an artificial CEI layer is effective for enhancing the high-voltage stability and rate capability of Ni-rich NCM cathodes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of East China University of Science & Technology is the property of Journal of East China University of Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the production of lithium-ion batteries (LIBs) and recycling of spent LIBs, a large amount of low-concentration lithium-containing wastewater (LCW) is generated. The recovery of Li from this medium has attracted significant global attention from both the environmental and economic perspectives. To achieve effective Li recycling, the features of impurity removal and the interactions among different ions must be understood. However, it is generally difficult to ensure highly efficient removal of impurity ions while retaining Li in the solution for further recovery. In this study, the removal of typical impurity ions from LCW and the interactions between these species were systematically investigated from the thermodynamic and kinetics aspects. It was found that the main impurities (e.g., Fe3+, Al3+, Ca2+, and Mg2+) could be efficiently removed with high Li recovery by controlling the ionic strength of the solution. The mechanisms of Fe3+, Al3+, Ca2+, and Mg2+ removal were investigated to identify the controlling steps and reaction kinetics. It was found that the precipitates are formed by a zero-order reaction, and the activation energies tend to be low with a sequence of fast chemical reactions that reach equilibrium very quickly. Moreover, this study focused on Li loss during removal of the impurities, and the corresponding removal rates of Fe3+, Al3+, Ca2+, and Mg2+ were found to be 99.8%, 99.5%, 99%, and 99.7%, respectively. Consequently, high-purity Li3PO4 was obtained via one-step precipitation. Thus, this research demonstrates a potential route for the effective recovery of Li from low-concentration LCW and for the appropriate treatment of acidic LCW. [ABSTRACT FROM AUTHOR]

Elemental analysis is a challenge for the development of High Throughput Experimentation (HTE) on thin film materials, and an even greater one when it comes to screening lithium-containing battery materials. In this regard, Laser-Induced Breakdown Spectroscopy has been evaluated here for the quantitative analysis of lithium in libraries of Li 2.3 PO 3.65 amorphous solid electrolyte films. The LIBS analysis of multiple samples with the same composition, but with thicknesses ranging from 50 to 700 nm, has revealed a linear trend in the intensity ratio of the Li I 610.35 nm and P I 214.91 nm emission lines, opening the way to rapid quantitative analysis of material libraries. The sensitivity of the technique finally allowed the detection of the Li I 670.79 nm emission line for film thicknesses down to 4 nm, corresponding to 0.2% of the ablated volume, or about 0.15 pg of Li. [Display omitted] • LIBS mapping was carried out on a library of Li2.3PO3.65 thin films from 50 to 700 nm thick. • Quantitative analysis of Li and P in LiPO thin films was achieved by LIBS. • LIBS is well suited for high-throughput analysis of lithium battery materials. • The Li I 670.79 nm emission line was detected for film thicknesses of down to 4 nm. [ABSTRACT FROM AUTHOR]

Development of lithium disilicate‐based glass‐ceramics critically depends on use of nucleating agent in the glass matrix. The present study reports the effect of externally added nucleating agent Li3PO4 in Li2O–K2O–MgO–ZnO–ZrO2–Al2O3–SiO2 system which is compared with a reference composition (GC1) (SiO2:Li2O = 2.16:1) prepared with in situ formed Li3PO4. For externally added Li3PO4, two compositions were studied. In one case (GC2) before addition of Li3PO4, SiO2:Li2O ratio in glass was maintained as 2.87:1 and in another case (GC3) SiO2:Li2O ratio in glass was maintained same as reference GC1 that is, 2.16:1. The glasses were characterized by using MAS‐NMR spectroscopy. Sintering and crystallization behavior of the glass‐ceramics was characterized by using XRD, SEM, DTA. Due to in situ formation of Li3PO4, GC1 resulted in a dense sample with finer crystals of lithium disilicate. In GC2 and GC3, externally added lithium phosphate, which was in the form of ultrafine aggregated particles, formed flower‐like colonies of radially outward crystals. Higher SiO2:Li2O ratio in GC2 resulted in lithium disilicate crystals and high viscous glass causing large air entrapment and so less densification. GC3 with higher lithia in glass showed higher densification than GC2 but only lithium metasilicate crystals were formed. [ABSTRACT FROM AUTHOR]

For application to all-solid-state thin film batteries, lithium boron phosphorus oxynitride (LiBPON) thin films were fabricated by RF magnetron sputtering technique of lithium borate (Li 3 BO 3) and lithium phosphate (Li 3 PO 4) target under N 2 atmosphere. To investigate the mixed former effect upon the LiBPON thin films, we prepared various films with controlled B and P contents. The LiBPON thin film formulation with nearly equal B and P contents showed the highest room-temperature lithium ionic conductivity of 3.52 × 10−6 S cm−1 and the lowest activation energy of 48.24 kJ mol−1 owing to the mixed former effect, the increased lithium content and nitridation. Infrared spectra of the glass thin films achieved two dominant peaks corresponding to BO 3 3− and PO 4 3− unit. N1s spectra were analyzed by X-ray photoelectron spectroscopy that the increased ionic conductivities observed were related to the formation of triply coordinated nitrogen. • Lithium boron phosphorus oxynitride (LiBPON) were fabricated by RF magnetron sputtering. • LiBPON shows the conductivity of 3.52 × 10−6 S cm−1 and the activation energy of 0.50 eV. • Due to the mixed former effect and the nitridation effect the ionic conductivity is increased. [ABSTRACT FROM AUTHOR]

The Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 layered oxide (NCM811) is attracting considerable attention as a high-capacity cathode material for rechargeable Li-ion batteries. However, due to its inherent structural/chemical/electrochemical instability, NCM811 with high Ni content suffers from significant performance degradation upon storage even in ambient atmospheres as well as during charge–discharge cycling. Herein, we demonstrate a simple but effective surface-tuning approach to mitigate storage-induced degradation of NCM811, which is based on the conversion of undesirable Li residues to a protective Li 3 PO 4 nanolayer via phosphate treatment. The accelerated storage stability test shows that phosphate-modified NCM811 exhibits remarkably improved electrochemical performance (capacity, cycle life, and rate capability) over the pristine one after being stored under harsh environmental conditions. A combined analytical study indicates that surface tuning through phosphate treatment enhances the storage stability of NCM811 by eliminating impurity-forming Li residues and producing a Li 3 PO 4 nanolayer that inhibits parasitic reactions at the electrode–electrolyte interface. Furthermore, Li 3 PO 4 provides an effective barrier to H 2 O and CO 2 infiltration into the particle agglomerates, thereby suppressing the loss of particle integrity. [ABSTRACT FROM AUTHOR]

Batteries on the market today still use liquid-type electrolytes, which can result in safety issues caused by electrolyte leakage. Therefore, studies that search for solid-state electrolytes are important for resolving these issues. In this research, a composite of lithium phosphate-montmorillonite-polyvinylidene fluoride (Li3PO4-MMT-PVDF) has been characterized with the aim of detecting the electrochemical performance of Li3PO4 with the addition of MMT. Li3PO4 samples were prepared through a solid-state reaction, which was then mixed with MMT, which had a composition ranging from 5 wt% to 20 wt%, and 1 wt% PVDF as a binder. This characterization was conducted with structural, morphological, and electrochemical aspects. The structural test showed that the X-ray diffraction (XRD) pattern was dominated by Li3PO4 peaks and MMT aluminosilicates. The electrochemical characterization indicated that the conductivity value of the composites was greater than that of Li3PO4. The highest conductivity was achieved with a 15 wt% MMT addition, with a dielectric-constant value of 74.9 at a frequency of 10 kHz.

Graphical abstract Highlights • A green cyclic and efficient process is proposed for recovering Li from spent LIBs. • Temperature is an important factor affecting Li 3 PO 4 precipitation behaviors. • Electrodialysis with cation-exchange membranes was used to treat Li 3 PO 4. • Li and P can be efficiently separated by electrodialysis. • The product of Li 2 CO 3 was in accord with the standard specification (Li 2 CO 3 -0). Abstract At present, the projected demand for lithium calls for processing all viable resources especially secondary resources. This paper presents a promising approach for recovering lithium from low lithium high-salt solution which is usually produced in the spent LIBs recycling process. The solution was firstly purified, and then lithium was precipitated by phosphate, the effects of operating conditions on the Li 3 PO 4 precipitation behaviors were evaluated. The results indicated that temperature is a more important factor than seed crystal or flocculant. After that, Li 3 PO 4 was dissolved by acid as the anolyte, and electrodialysis with cation-exchange membranes was used to investigate the separation performance of Li and P. The results showed that Li and P was effectively separated by electrodialysis, and the P/Li mass ratio of the catholyte was reduced to 0.23 (6.5 times lower compared to a feed P/Li ratio of 1.48). Deep separation of lithium and phosphorus in the catholyte was achieved by raising pH to make the lithium precipitated with the permeated phosphorus. The lithium concentration of purified catholyte was 22.5 g/L and was used to prepare lithium carbonate. The Li 2 CO 3 precipitation rate reached 88.3% at 80 °C under CO 3 3−/Li+ molar ratio of 1.1:2. The final product of lithium carbonate was in accord with the standard specification (Li 2 CO 3 -0, GB/T 11075-2013). The results of this study provide an efficient and green cyclic process for recovering lithium from spent LIBs. [ABSTRACT FROM AUTHOR]

In this study, carbon-coated lithium iron phosphate (LiFePO 4 /C, denoted as LFP/C) composite cathode materials were prepared through wet ball milling and spray drying. Ground and spherical α-Fe 2 O 3 precursors were used to synthesize LFP samples. Wet ball milling and a solvothermal method were used to prepare α-Fe 2 O 3 particles with a smaller size and spherical morphology, respectively. The as-prepared α-Fe 2 O 3 was used to synthesize LFP/C composites in order to investigate the effects of α-Fe 2 O 3 size and morphology on the electrochemical performance of LFP/C cathode materials. Charge–discharge measurements revealed that the LFP/C cathode materials prepared from the ground and spherical α-Fe 2 O 3 precursors delivered a similar specific discharge capacity of approximately 150 mAh/g at 0.1 C and 96 mAh/g at 10 C, which was higher than that of the LFP/C cathode materials prepared using the irregular and unground α-Fe 2 O 3 (the discharge capacity was 135 mAh/g at 0.1 C and 62 mAh/g at 10 C). The results reveal that the size and morphology of iron precursors have a profound influence on the electrochemical properties of LFP/C materials. The results obtained in this study can serve as a reference in the use of the solid-state method to produce low-cost LFP/C cathode materials with favorable consistent properties and high electrochemical performance. [ABSTRACT FROM AUTHOR]

A novel process recycling Li from the spent LiFePO 4 cathode material has been put forward. The new LiFePO 4 sample is synthesized through hydrothermal reaction by using recovered Li 3 PO 4 as Li source and FeSO 4 ·7H 2 O as Fe source. The morphologies, structure and physicochemical properties of the re-synthesized LiFePO 4 cathode material were characterized by Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurement. The results showed that the morphology and particle size of re-synthesized LiFePO 4 samples become more regular and smaller with the increase of the hydrothermal reaction temperature. Besides, it has been found that the LiFePO 4 cathode material synthesized at 200 °C showed excellent electrochemical properties which deliver a high initial capacity of 144.25 mAh/g at the rate of 1 C and high capacity retention of 96.7% after 200 cycles. Therefore, this work provides a new strategy for recovery and recycle of the spent LiFePO 4 cathode scraps. [ABSTRACT FROM AUTHOR]

This paper presents the extraction process of lithium from lepidolite concentrate by roasting with NaHSO 4 followed by water leaching. Results from TG-DSC analysis of feed material and XRD scans of solids justified the thermodynamic modelling of chemical reactions predicted using HSC software package. The roasting of NaHSO 4 /lepidolite concentrate mixture of mass ratio 2.5/1.0 at 500 °C followed by water leaching at 95 °C yielded 96% of Li extraction. Under these conditions, about 79% Rb and 73% Cs were also leached from calcined lepidolite material. Purification of the lepidolite leach liquor by adjusting the solution pH to 9 using caustic soda resulted in the precipitation of cryolite (NaAlF 6) as a primary phase. The purified liquor with pH adjusted to 12 was treated with phosphoric acid to precipitate Li 3 PO 4 to achieve a recovery of about 93%. • HSC modelling of roasting lepidolite with NaHSO 4 and confirming products using TGA-DTA • Roasting lepidolite with NaHSO 4 to produce water soluble lithium salts and confirming products using XRD • Elemental mass balance for roasting and water leaching of lithium from roasted product • Purification of leach liquor and precipitation of lithium phosphate [ABSTRACT FROM AUTHOR]

Hollow inorganic nanostructures are important due to their applications in energy storage and conversion, catalysis, gas sensing, and biomedicine. Li3PO4 is used as an isomerization catalyst for propylene oxide to selectively give allyl alcohol. We used a facile template-free method to synthesize hollow Li3PO4 nanoparticles with size range of 500nm to 1500nm. The effect of concentration, agitation, ripening temperature and the ratio of starting reagents on the hollowing process is investigated. The most important factor to influence the hollowness was found to be the ratio of lithium ion to phosphate ion; as the ratio increases, the hollowness of the particles increases. When this ratio reached 3, the hollow nanostructures become dominant. As an isomerization catalyst for propylene oxide, 4-Li3PO4 exhibited the highest conversion and best selectivity of allyl alcohol. The hydroxide ion of the precursor is adsorbed on the surface of the Li3PO4 particles which results in different surface basicity. A new template-free and mass-production available route to synthesize hollow Li3PO4 nanospheres was evaluated. Agitation, higher OH-/, higher concentration of mother liquor and higher temperature are all advantageous for the Li3PO4 hollowing process. [ABSTRACT FROM AUTHOR]

A metal-organic chemical vapor deposition (MOCVD) process was developed to deposit high quality lithium phosphate (Li 3 PO 4 ) thin films using lithium dipivaloylmethanate (Li(DPM)), triethyl phosphate (TEP) and H 2 O as the precursor materials. The use of water as an activating agent helps stimulate the formation of a lithium phosphate structure and tailor the process to the reaction-controlled regime. Consequently, lithium phosphate thin films were deposited uniformly with ~ 46% step coverage on trenched substrates with an aspect ratio of 6:1, demonstrating the feasibility of the three-dimensional (3D) deposition of Li 3 PO 4 by MOCVD. In the temperature range of 300–450 °C, an increase in temperature led to the development of crystallinity, increased growth rate, and decreased lithium concentration. The concentrations of Li, P, and O were homogeneous along the film depth. The films deposited at 400 °C exhibited the highest ionic conductivity (5 × 10 − 8 S cm − 1 ) due to the optimal elemental ratio and crystallinity. The method developed in this study can also be applied for the uniform deposition of other materials on 3D geometries by using suitable activating agents. [ABSTRACT FROM AUTHOR]

Collective characterizations of prepared lithium phosphate glass together with samples containing increasing added MgO contents (0-2 mol%) were carried out by differential thermal analysis (DTA), spectroscopic ellipsometry (SE) and photoluminescence (PL) measurements. From the DTA profile, the glass transition temperature T and crystallization onset temperature T are estimated. The thermal stability factor was higher than 100 °C suggesting that this glass exhibits a good thermal stability and consequently is suitable to be a potential candidate for fiber drawing. Furthermore, the variation of the Δ T as function of MgO contents has a minimum at 1 mol% of MgO. The refractive index and extinction coefficient data were obtained by analyzing the experimental spectra of tan Ψ and cosΔ measured by SE. The complex dielectric functions ( ε = ε + ιε ) of the samples were estimated from regression analysis. Some of the optical absorption parameters, such as high-frequency dielectric constant, ε , the average values of oscillator strength, S , wavelength of single oscillator, λ , plasma frequency, ω and relaxation time, τ, have been evaluated. The PL spectra of the MgO-doped glass under 325-nm excitation wavelength were studied. The dependence of PL spectra on doping concentration shows a quenching of the PL intensity for MgO concentration above 1 mol%. The variations of the photoluminescence intensity, thermal stability refractive index and optical constants gave an indication to use the prepared glasses for design of novel functional optical materials with higher optical performance. [ABSTRACT FROM AUTHOR]

This paper reports the thermoluminescence (TL) properties of Li 3 PO 4 doped with rare earth Dy3+ ions. The solid state diffusion method is used to synthesize phosphors with varying concentrations of the dopant (0.1, 0.2, 0.3, 0.4 and 0.5 mol%). Characterization of the samples is performed using X-ray diffraction (XRD), Fourier Transform Infrared-Attenuated Total Reflection spectroscopy (FTIR-ATR) and Scanning Electron Microscopy (SEM). Samples are irradiated with γ rays in the dose range of 10 Gy to 6 kGy and by UV-C rays (254 nm) for exposure duration ranging from 0.5 to 5 h. Maximum TL intensity in both cases is observed for the phosphor doped with 0.2 mol% Dy3+. While a linear TL response is found for the entire duration of UV-C irradiation, the dose response for γ irradiation stays linear upto 3 kGy for the high temperature peak at 335∘C. Appreciable repeatability values are found (for both γ and UV-C irradiated samples) and significantly low fading (for the UV-C irradiated phosphor) is reported. The computerized glow curve deconvolution has been done using an R-package, "tgcd: Thermoluminescence Glow Curve Deconvolution" by assuming the Kitis general order kinetics model. Chen's peak shape method is utilized to extract trapping parameters such as the order of kinetics (b), shape factor (μ g), frequency factor (s), activation energy (E) and trap density (n 0). Various promising properties of this material are found suggesting that it could be used as a TL dosimeter. • Synthesis of Li 3 PO 4 :Dy using Solid State Diffusion method. • TL properties of UV-C (254 nm) irradiated Li 3 PO 4 :Dy reported for the first time. • Prominent peak found at high temperature (∼ 340∘C). • Significantly low fading for UV-C irradiated phosphor, compared to standard TLDs. • Extraction of kinetic parameters done using "tgcd", an R-package. [ABSTRACT FROM AUTHOR]

Battery recycling has attracted attention as a solution to maintain the chain of demand and supply. First time, a selective biological process assisted by a neutrophilic microorganism for lithium recovery from Li-FP battery cathodes is exhibited. Thiobacillus thioparus , a biosafety level-1 bacterium is used to selectively leach lithium at near-neutral pH. The study showed the leaching was efficient, selective, and environmentally friendly as it could recover 65–98% lithium, with negligible iron, under different experimental conditions supported solely by bacterial activity. Thereafter, lithium was recovered as Li 3 PO 4 from the leach solution, which was subsequently reuse as a culture medium to grow an alkaliphilic bacteria for other applications. The liquid and solid residues were characterized by FAAS, ICP-MS, XRD, FESEM, XPS, UV–visible, and FTIR techniques. The developed process could suggest a sustainable alternative for reclaiming selective recovery of critical metal, which needs to meet the demand for continuous consumption in battery production. [Display omitted] [ABSTRACT FROM AUTHOR]

Coating the surface of the cathode active material of all-solid-state batteries with sulfide-based solid electrolytes is key for improving and enhancing the battery performance. Although lithium niobate (LiNbO 3 ) is one of the most representative coating materials, its low durability at a highly charged potential and high temperature is an impediment to the realization of high-performance all-solid-state batteries. In this study, we developed new hybrid coating materials consisting of lithium niobate (Li-Nb-O) and lithium phosphate (Li-P-O) and investigated the influence of the ratio of P/(Nb + P) on the durability performance. The cathode half-cells, using a sulfide-based solid electrolyte Li 6 PS 5 Cl/cathode active material, LiNi 0.5 Co 0.2 Mn 0.3 O 2 , coated with the new hybrid coating materials of LiP x Nb 1- x O 3 ( x = 0-1), were exposed to harsh conditions (60 °C and 4.55 V vs Li/Li + ) for 120 h as a degradation test. P substitution resulted in higher durability and lower interfacial resistance. In particular, the hybrid coating with x = 0.5 performed better, in terms of capacity retention and interfacial resistance, than those with other compositions of niobate and phosphate. The coated cathode active materials were analyzed using various analytical techniques such as scanning electron microscopy/energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy (XAS) to elucidate the improvement mechanism. Moreover, the degraded cathodes were observed using time-of-flight secondary-ion mass spectrometry, TEM/electron diffraction, and XAS. These analyses revealed that the Nb-O-P coordination in the hybrid coating material captured O by P. The coordination suppressed the release of O from the coating layer as a decomposition side reaction to realize a higher durability than that of LiNbO 3 .

Lithium metal with high theoretical capacity (3860 mAh/g) and low operational voltage (−3.04 V vs. standard hydrogen electrode) reflects to be one of the most high energy density anodes for energy storage devices. While, its high chemical activity to continuously react with electrolytes causing low coulombic efficiency and formation of lithium dendrites leading safety concern limits practical applications. To conquer these challenges, amorphous Li 3 PO 4 thin films with thickness of 0–200 nm are directly coated on the surface of Li metal foil via magnetron sputtering. The as-prepared Li 3 PO 4 has almost insulated property with electronic conductivity of 1.4 × 10 −10 S/cm and ionic conductivity of 2.8 × 10 −8 S/cm. The conformal coating layer Li 3 PO 4 can successfully suppress the lithium dendrites growth and improve its life span. The remarkable improvements of the Li 3 PO 4 -coated Li electrodes are mainly attributed to high chemical stability as well as amorphous nature of Li 3 PO 4 , which leads layer-by-layer growth Li film rather than islands form dendrites. [ABSTRACT FROM AUTHOR]