Metal Phosphate Materials Research Articles

Lattice engineering of high-entropy olivine-type lithium metal phosphate as high-voltage cathodes

Engineering of high-entropy cathode materials for lithium-ion batteries has been actively pursued owing to the outstanding conductivity of high-entropy materials benefited from the maximum entropy and unique antisite disordering structure. Olivine lithium metal phosphates such as LiMnPO4 and LiNiPO4 feature high working voltages but low capacities due to their insulation nature. In this work, the synthesis of the high-entropy lithium metal phosphate materials (HELMPs) is realized by combining mechanochemistry with a calcination method. By regulating lattice of HELMPs, the high-entropy Li(Mn0.35Fe0.35Co0.1Mg0.1Ca0.1)PO4 reveals three typical high-voltage plateaus in charge–discharge curves corresponding to the redox of Fe, Mn, and Co in the voltage range of 2.0–4.9 V vs Li+/Li, and a much higher initial capacity than LiMnPO4 (104 vs 15 mAh g−1).

Outstanding electrochemical performance of nickel-cobalt phosphate sheets with abundant mesopores for use in aqueous asymmetric supercapacitors and Ni–Zn batteries

Transition metal phosphate materials (TMPs), especially bimetallic phosphates, have been regarded as an attractive electrode material for energy storage applications. However, phosphate materials with high capacitance and long cycle stability have scarcely been reported in the literature, due to their poor conductivity and small surface area. In this work, novel mesoporous nickel-cobalt phosphate sheets supported on conductive nickel foam (NF) have been successfully prepared by a facile and straightforward hydrothermal reaction. The resulting material shows a particularly attractive electrochemical performance, with a fairly high specific capacitance of 3722 F g−1 (7.44 F cm−2) at a current density of 1 A g−1. Even at current density values of 25 A g−1, the specific capacitance remains sufficiently high, that is, 1900 F g−1 (3.8 F cm−2). The significantly improved capacitance of nickel-cobalt phosphate material arises from the effective combination of the synergistic effect between two metal species, abundant mesopores and the high specific area of sheets, contributing to faster electrochemical kinetics, shortening ion transport channels and providing plentiful active sites for reaction. Furthermore, an asymmetric supercapacitor device using nickel-cobalt phosphate as cathode electrode and activated carbon (AC) as anode electrode has been assembled. This device exhibits a prominent energy density of 57.22 Wh kg−1 at a power density of 400 W kg−1 and excellent cycling performance at a large current density of 30 A g−1 (about 98% capacitance retention for 30000 cycles). Surprisingly, nickel-cobalt phosphate sheets firstly applied in an aqueous Ni–Zn battery deliver a high capacity of 195.5 mAh g−1 at 1 A g−1 and good rate performance (104.6 mAh g−1 at 10 A g−1). Such experimental findings suggest that mesoporous nickel-cobalt phosphate sheets are candidate materials to be employed in aqueous supercapacitors and Ni–Zn batteries.

Template-free synthesis of mesoporous and amorphous transition metal phosphate materials.

We present how mesoporosity can be engineered in transition metal phosphate (TMPs) materials in a template-free manner. The method involves the transformation of a precursor metal phosphate phase, called M-struvite (NH4MPO4·6H2O, M = Mg2+, Ni2+, Co2+, NixCo1-x2+). It relies on the thermal decomposition of crystalline M-struvite precursors to an amorphous and simultaneously mesoporous phase, which forms during degassing of NH3 and H2O. The temporal evolution of mesoporous frameworks and the response of the metal coordination environment were followed by in situ and ex situ scattering and diffraction, as well as X-ray spectroscopy. Despite sharing the same precursor struvite structure, different amorphous and mesoporous structures were obtained depending on the involved transition metal. We highlight the systematic differences in absolute surface area, pore shape, pore size, and phase transitions depending on the metal cation present in the analogous M-struvites. The amorphous structures of thermally decomposed Mg-, Ni- and NixCo1-x-struvites exhibit high surface areas and pore volumes (240 m2 g-1 and 0.32 cm-3 g-1 for Mg and 90 m2 g-1 and 0.13 cm-3 g-1 for Ni). We propose that the low-cost, environmentally friendly M-struvites could be obtained as recycling products from industrial and agricultural wastewaters. These waste products could be then upcycled into mesoporous TMPs through a simple thermal treatment for further application, for instance in (electro)catalysis.

Analyzing synthesis routes for BaCuPO4: implications for hydrogen evolution and supercapattery performance.

In recent years, energy storage and conversion tools have evolved significantly in response to rising energy demands. Owing to their large surface area, superior electric and chemical stabilities, and thermal conductivities, barium copper phosphate (BaCuPO4) materials are promising electrode materials for electrochemical energy storage systems. In this study, the synthesis of nanostructures (NSs) using hydrothermal and chemical precipitation methods and exploring the electrochemical characteristics of BaCuPO4 in asymmetric supercapacitors provides a comparative investigation. Systematic characterization shows that nanomaterials prepared by applying the hydrothermal method have a more crystalline and large surface area than chemical precipitation. In the three cell arrangements, the hydrothermally prepared BaCuPO4 NSs delivered a high specific capacity (764.4 C g-1) compared to the chemical precipitation route (660 C g-1). Additionally, the supercapattery associated with the two electrode assemblages delivers an optimum specific capacity of 77 C g-1. The energy and power density of BaCuPO4//AC NSs were 52.13 W h kg-1 and 950 W kg-1, respectively. A durability test was also performed with BaCuPO4//AC NSs for 5000 consecutive cycles. Further, the coulombic efficiency and capacity retention of BaCuPO4//AC after 5000 cycles were 81% and 92%, respectively. Bimetallic phosphate is comparatively suggested for future perspectives towards HER to overcome the performance of single metal phosphate materials. This is the first approach, we are aware of, for investigating the electrochemical behavior of BaCuPO4, and our results suggest that it may be useful as an electrode material in electrochemical systems requiring high energy and rate capabilities.

Trigger action of copper aminophosphate (X-CuAP) nanoparticles for enhanced electrochemical, photocatalyst and biological properties

The (en)-CuAP nanocrystals were synthesized by hydrothermal method. This material was designed rarely with it envelop good records in the characterization part, and morphologies also very clearly shown in the FE-SEM and HR-TEM analysis. The monoclinic phase of the (en)-CuAP nanocrystals functional groups was identified to the best coincide nature of the FT-IR and Raman spectroscopy studies. The obtained band gap energy is 2.65eV, which were lower than the other metal phosphate materials. Moreover, (en)-copper aminophosphate was tested to the electrochemical fabrication of the Phloroglucinol and Riboflavin, herewith phloroglucinol is an anodic peak and Riboflavin is better reduction peaks were appeared in the cyclic voltammetry studies. Hence, (en)-CuAP nanocrystals was electrochemically optimized both conditions, and its gives good transition at low concentrations. The modified electrodes have large surface area, high conductivity, and high catalytic activity of (en)-CuAP/GCE. The proposed sensors are high sensitivity for Phloroglucinol and Riboflavin detection and it was successfully developed with better performance of the electrochemical sensor. The (en)-CuAP nanocrystals have better reusability performance and enhanced to an excellent photocatalytic activities and antibacterial activities.

Insights into Transition Metal Phosphate Materials for Efficient Electrocatalysis

AbstractOver the past decade, transition metal phosphate materials have attracted enormous interest for various functional devices. In addition to being low‐cost, earth‐abundant and environmentally benign, transition metal phosphates have several unique advantages including high stability, unique chemical/physical characteristics and tunable multifunctionality, making them ideally suited for advanced highly‐efficiency energy conversion and storage applications. In this Review, the synthetic strategies for transition metal phosphates are summarized, and the most recent advances in the development of transition metal phosphates are described for efficient electrocatalysis such as oxygen evolution, hydrogen evolution and oxygen reduction reactions, highlighting the impact of their morphologies and structures on the electrochemical performance and practical applications in overall water splitting and rechargeable metal‐air batteries. Finally, the challenges facing the development of transition metal phosphates in the field of energy conversion and storage are outlined, together with directions of further research and perspectives.

Ultrasonic treatment of Co7(PO4)2(HPO4)4 using NMP for supercapacitors and oxygen evolution reaction

In the alkaline system, the mechanism relationships of the transition metal phosphate materials between pseudocapacitors and OER are analyzed, more active sites, excellent conductivity and enhanced intrinsic activity are important factors in enhancing their OER and capacitance performances. In this study, the capacitance of synthesized Co7(PO4)2(HPO4)4 after ultrasonic treatment with N-methyl-pyrrolidinone (NMP) improved 20.1 % (345 F g−1 at 1 A g−1), the overpotential for OER reduced 20 mV (293 mV at 10 mA cm−2). Based on detailed characterization analysis, ultrasonic treatment with NMP does not destroy the phases and the surface phosphate groups of the materials, but reduce the overall particle size, improve the pore volume and create some new interfaces originally located inside the material. These changes bring increased active sites, reduced internal resistance, enhanced charge transfer capability and improved intrinsic activity to the synthesized Co7(PO4)2(HPO4)4, enhancing its OER and capacitance efficiency. Additionally, the ultrasonic treatment can achieve those changes, which is most likely achieved by sacrificing some mesopores with small diameters, it also provides a simple and convenient method for enhancing the performance of other three-dimensional mesoporous materials.

Looking at Patent Law: Patenting Lithium Metal Phosphate Materials for Rechargeable Batteries—A Case Study

Looking at Patent Law: Patenting Lithium Metal Phosphate Materials for Rechargeable Batteries—A Case Study

Interfacing DNA Oligonucleotides with Calcium Phosphate and Other Metal Phosphates.

Calcium phosphate (CaP) has long been used for DNA delivery, although its fundamental interaction with DNA, especially with single-stranded DNA oligonucleotides, remains to be fully understood. Using fluorescently labeled oligonucleotides, we herein studied DNA adsorption isotherm and the effect of DNA length and sequence. Longer DNAs are adsorbed more strongly, and at neutral pH, poly-C DNAs are adsorbed more than the other three DNA homopolymers. However, at near pH 11, the pH of CaP synthesis, T30 DNA is adsorbed more strongly than C30 or A30. This can explain why T30 and G30 can fully inhibit the growth of CaP, while A30 and C30 only retarded its growth kinetics. DNA adsorption also reduces aggregation of CaP. DNA desorption experiments were carried out using concentrated urea, thymidine, or inorganic phosphate as competitors, and desorption was observed only in the presence of phosphate, suggesting that DNA uses its phosphate backbone to interact with the CaP surface. Desorption was also promoted by raising the NaCl concentration suggesting the electrostatic nature of interaction. Finally, ten different metal phosphate materials were synthesized by co-precipitating each metal ion (Ce3+, Fe3+, Ca2+, Ni2+, Zn2+, Mn2+, Ba2+, Cu2+, Sr2+, Co2+), and DNA adsorption by these phosphate precipitants was found to be related to their surface charge and metal chemistry. This work has revealed fundamental surface science of DNA adsorption by CaP and other metal phosphate salts, and this knowledge might be useful for gene delivery, biomineralization, and DNA-directed assembly of metal phosphate materials.

Lithium metal phosphates, power and automotive applications

Lithium metal phosphate materials are the newest generation of active materials. With the limited number of cathode materials available at present and the prevalence of transition metal oxide cathodes, phosphates are able to answer the rising safety concerns surrounding the oxide chemistry. These inherent safety limitations have until now prevented lithium ion batteries in general from entering the large format applications markets such as electric and hybrid electric vehicles. Iron-based olivine phosphate has been the focus of extensive research: intrinsic thermal stability and continual improvement of its performance characteristics have geared the industry to a fast track adoption of this chemistry for the larger format applications. Recently developed vanadium-based phosphates possess operating voltages of 3.65 V for Li 3V 2(PO 4) 3 and 4.05 V for LiVPO 4F, both of which are higher than the iron-based phosphate. The high power capability of Li 3V 2(PO 4) 3 makes it ideal for applications that require power; LiVPO 4F on the other hand has high energy and a desirable cycling characteristic that makes it ideal for energy-demanding applications such as PHEV and EV. These materials are the best fit for the ever-increasing demand for energy, power and thermal stability that is essential in the large format arena.

Effect of Incorporating Nanoporous Metal Phosphate Materials on the Compressive Strength of Portland Cement

Nanoporous metal phosphate (NP-MPO) materials are being developed for removal of contaminant oxyanions (As(OH), , and ), and cations (mercury, cadmium, and lead) from water and waste streams. Following sequestration, incorporation of metal laden NP-MPOs as a portion of cement formulation would provide an efficient and low-cost way to immobilize metal laden NP-MPOs in an easily handled waste form suitable for permanent disposal. There are no known investigations regarding the incorporation of NP-MPOs in concrete and the effects imparted on the physical and mechanical properties of concrete. Results of this investigation demonstrated that incorporating of NP-MPO materials requires additional water in the concrete formulation which decreases the compressive strength. Thus, incorporation of NP-MPOs in concrete may not serve as an efficient means for long-term disposal.

Nanoporous transition metal phosphate materials for sequestration of redox sensitive contaminants

Nanoporous transition metal phosphate materials for sequestration of redox sensitive contaminants

A Mechanism for Phosphate Hardening and Prospects for the Use of Metal Phosphate Materials (An Overview). Part II. Adhesive Properties of Binding Phosphate Materials

A mechanism for hardening of phosphate materials and the role of hydrogen bonding in this mechanism has been considered. The adhesive properties of binding phosphate materials are discussed and factors affecting the buildup of adhesive bonds between the binding material and the hard surface of a substrate or particles of the filler are analyzed. Correlations between the properties of the binding phosphate material and the cohesive forces are considered.

A Mechanism for Phosphate Hardening and Prospects for the Use of Metal Phosphate Materials (A Review). Part I. The Nature of Hydrogen Bonding and Its Function in the Mechanism of Phosphate Hardening

The physical chemistry of multistep hardening of phosphate bonding materials is considered. The function of hydrogen bonds in the phosphate hardening mechanism and their effect on the adhesive properties of phosphate bonding materials are discussed. Techniques for enhancing the adhesive properties of phosphate binders using powdered oxides, hydroxides, and salts and their involvement in acid-base reactions are considered. Bonding materials for nonfired refractories, corrosion-resistance coatings and mortars, and areas for their potential applications are proposed.

Di-tert-butyl phosphate as synthon for metal phosphate materials via single-source coordination polymers [M(dtbp)(2)](n) (M = Mn, Cu) and [Cd(dtbp)(2)(H2O)](n) (dtbp-H = (tBuO)(2)P(O)OH).

Reaction of M(OAc)(2).xH(2)O (M = Mn, Cu, or Cd) with di-tert-butyl phosphate (dtbp-H) in a 1:2 molar ratio in methanol followed by slow crystallization of the resultant solid in MeOH/THF medium results in the formation of three new polymeric metal phosphates [M(dtbp)(2)](n)() [M = Mn, 1 (beige); M = Cu, 2 (blue)] and [Cd(dtbp)(2)(H(2)O)](n)(), 3 (colorless)] in good yields. The formation of [Mn(dtbp)(2)](n) (1) proceeds via tetrameric manganese phosphate [Mn(4)(O)(dtbp)(6)] (4), which has been isolated in an analytically pure form. Perfectly air- and moisture-stable compounds 1-4 were characterized with the aid of analytical, thermoanalytical, and spectroscopic techniques. The molecular structures of 1-3 were further established by single-crystal X-ray diffraction studies. Crystal data for 1: C(32)H(72)Mn(2)O(16)P(4), monoclinic, P2(1)/c, a = 19.957(4) A, b = 13.419(1) A, c = 18.083(2) A, beta = 91.25(2) degrees, Z = 4. Crystal data for 2: C(16)H(36)CuO(8)P(2), orthorhombic, Pccn, a = 23.777(2) A, b = 10.074(1) A, c = 10.090(1) A, Z = 4. Crystal data for 3: C(48)H(114)Cd(3)O(27)P(6), triclinic, P1, a = 12.689(3) A, b = 14.364(3) A, c = 22.491(5) A, alpha = 84.54(3) degrees, beta = 79.43(3) degrees, gamma = 70.03(3) degrees, Z = 2. The diffraction studies reveal three different structural forms for the three compounds investigated, each possessing a one-dimensional coordination polymeric structure. While alternating triple and single dtbp bridges are found between the adjacent Mn(2+) ions in 1, uniform double dtbp bridges across the adjacent Cu(2+) ions are present in 2. The cadmium ions in the structure of 3 are pentacoordinated. Thermal analysis (TGA and DSC) indicates that compounds 1-3 convert to the corresponding crystalline metaphosphate materials M(PO(3))(2), in each case at temperatures below 500 degrees C. Similarly, the thermal decomposition of 4 results in the formation of Mn(PO(3))(3) and Mn(2)P(2)O(7). The final materials obtained by independent thermal decomposition of bulk samples have been characterized using IR spectroscopic, powder diffraction, and N(2) adsorption studies.

Di-tert-butylphosphate Complexes of Mn(II) and Cu(II) as Single-Source Precursors for Metal Phosphate Materials

Abstract Octahedral Mn(II) and Cu(II) di-tert-butylphosphate (L) complexes [ML2(imz)4] have been synthesized and characterized using IR, UV-vis, luminescence, and EPR spectroscopy and single crystal X-ray diffraction studies. Thermal decomposition of both the complexes (probed by TGA, DTA, and DSC) indicate stepwise elimination of iso-butene, imidazole and water to finally yield the respective ceramic materials Mn(PO3)2 or Cu(PO3)2.