91 results about "Lamellar crystals" patented technology

The invention relates to the technical field of friction plates for vehicles, and particularly discloses a resin-based friction plate for an aluminum-ceramic brake disc and a preparation method of the resin-based friction plate for the aluminum-ceramic brake disc. Steel fibers serve as a main reinforcing phase, the structural strength of the material is improved, and meanwhile the steel fibers are good friction increasing materials; the reduced iron powder can improve the heat-conducting property of the brake pad and reduce the decline of the friction coefficient at high temperature; the red copper powder and the brass powder are good lubricants, the stability of single braking can be improved, and meanwhile abrasion is reduced; the silicon carbide mainly plays a role in increasing the high-temperature friction coefficient; molybdenum disulfide is beneficial for improving the recovery performance after high-temperature decline and reducing abrasion; antimony sulfide is lubricated at high temperature, and the friction coefficient in the decline stage is increased; silicon carbide is a high-hardness material, so that the friction coefficient is increased; the potassium magnesium titanate lamellar crystal improves the damping characteristic of the material and absorbs vibration and reduces noise, and the resin-based friction plate has the advantages of being high in strength, good in heat conduction, stable in friction performance, resistant to abrasion, comfortable in braking and the like and meets the use requirement of an aluminum ceramic brake disc.

The invention discloses a preparation method of a high-rate wide-temperature-range regenerated graphite negative electrode material, and belongs to the technical field of lithium ion battery recovery. The invention provides a preparation method of a high-magnification wide-temperature-range regenerated graphite negative electrode material, which combines a multi-section high-temperature synergistic treatment means and a lithium-rich catalytic surface modification technology, realizes impurity removal of a waste graphite negative electrode under the condition of lower energy consumption, and realizes effective repair of a graphite crystal structure. According to the method, through the synergistic effect of ultrahigh-temperature gasification and the reactive atmosphere, trace metal impurities which are most difficult to remove and fluorine-containing compounds with thermal stability are almost thoroughly removed, and the purity of the regenerated graphite is improved to be close to the level of a primary material (the purity gt is 99.9%); and a lithium-rich catalytic surface modification technology is adopted, so that the graphite surface can be stabilized, and the rate capability and low-temperature performance of the material are improved. The graphitization degree (gt; 95%) of the material is remarkably improved through the in-situ defect repairing effect driven by ultrahigh temperature, and the highly-ordered layered crystal structure and the excellent conductive network of the material are recovered.

The application discloses a positive electrode active material, a positive electrode including the positive electrode active material, and a rechargeable lithium battery including the positive electrode. The positive electrode active material includes first particles including a first lithium composite oxide having a spinel crystal structure, second particles including a second lithium composite oxide having a layered crystal structure, and third particles including a third lithium composite oxide having a layered crystal structure. The average particle size of the second particles is larger than that of the third particles. The first particle has a first weight ratio relative to a total weight of the first particle, the second particle, and the third particle. The second particles have a second weight ratio relative to the total weight. The third particles have a third weight ratio relative to the total weight. The first weight ratio is greater than the sum of the second weight ratio and the third weight ratio.

[Problem] The present invention provides a friction pair having excellent low-speed performance stability, comprising a disc brake pad having a friction material composed of a friction material composition and a stainless steel disc rotor. The friction material composition comprises a binder, a fiber base material, and a friction modifier, and is free of copper and iron-based metal fibers. [Solution] The present invention utilizes a friction material composition containing 20-30% by weight of a titanate as an inorganic friction modifier relative to the total weight of the friction material composition, and is free of mica and vermiculite. The titanate is preferably lithium potassium titanate having a layered crystal structure.

The invention discloses a highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator for X-ray detection imaging and a preparation method of the highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator, and relates to the technical field of radiation detection and scintillation materials, the highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator comprises phenethyl ammonium bromide, cesium lead tribromide and ammonium thiocyanate, the molar ratio of the phenethyl ammonium bromide to the cesium lead tribromide to the ammonium thiocyanate is 2: 4: 2, the scintillator contains a methylamine thiocyanate additive which accounts for 0-1 equivalent weight of the dosage of the ammonium thiocyanate, and the scintillator is of a flaky polycrystal structure; the perovskite crystal of the polycrystalline wafer has a quasi-two-dimensional layered crystal structure, and each crystal grain is arranged in a height orientation manner, so that the layered crystal face is parallel to the main plane of the scintillator sheet. According to the highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator for X-ray detection imaging and the preparation method of the highly-oriented quasi-two-dimensional perovskite multi-wafer scintillator, a highly-oriented layered structure is formed in the crystal, diffuse scattering of emergent light is greatly reduced, brightness uniformity and spatial resolution of X-ray imaging are improved, and a finer imaging effect is achieved.

This invention discloses a type of sodium titanate with a layered crystal structure, its preparation method, and its application in aqueous magnesium-ion batteries, belonging to the field of aqueous magnesium-ion battery technology. This invention uses sodium titanate with a layered crystal structure as the negative electrode material in aqueous magnesium-ion batteries. Due to its excellent chemical and structural stability, sodium titanate can achieve reversible magnesium deposition in aqueous magnesium electrolytes. 2+ Intercalation / extraction. This invention synthesizes Na via a hydrothermal method and a high-temperature annealing process. 2 Ti 2 O 5 And Na 2 Ti 3 O 7 Materials. In magnesium chloride electrolyte, both sodium titanate materials exhibit extremely low charge / discharge potentials (Na). 2 Ti 2 O 5 -1.3 to -0.6V vs. SCE; Na 2 Ti 3 O 7 (-1.5 to -1V vs. SCE) and good cycle stability. Furthermore, Na... 2 Ti 2 O 5 The half-cell exhibits a charge-discharge specific capacity of up to 213 mAh / g at a current density of 2 A / g, and maintains a high specific capacity of 150 mAh / g even at a high current density of 10 A / g. The sodium titanate of this invention is an ideal anode material for aqueous magnesium batteries, possessing both low cost and environmental friendliness, and shows great promise for application in the field of aqueous magnesium-ion energy storage.

To provide a friction couple having an enhanced effect and stability in a low speed range, where the friction couple has a disc brake pad having a friction material manufactured from a friction material composition having a binder, a fiber base, and a friction modifier, without containing a copper component and a ferrous metallic fiber, and a stainless steel disc rotor. The present invention uses a friction material composition containing 20-30 weight % of a titanate relative to an entire friction material composition as an inorganic friction modifier without containing an inorganic friction modifier that has a Mohs hardness of 4 or less and is cleavable. The above-explained titanate is preferably a layer crystal structure lithium potassium titanate.

The invention relates to a multi-metal element nano-aluminum adjuvant and a preparation method and application thereof, the nano-aluminum adjuvant is a nano-particle containing an aluminum element and at least one metal element selected from magnesium, zinc and calcium, the nano-particle has a layered crystal structure, and the particle size is distributed in a range of 20-2000 nm. The difunctional nano-aluminum adjuvant has the beneficial effects that the difunctional nano-aluminum adjuvant is simple and convenient in preparation method, definite in component and uniform in particle size, the particle size of the particles can be manually regulated and controlled, and the difunctional nano-aluminum adjuvant can directly promote antigen presenting cells to be mature and activated and carry out MHC-I or II type antigen presentation.

The invention relates to a positive electrode and a manufacturing method thereof. The positive electrode includes a first positive electrode active material having an olivine crystal structure and a second positive electrode active material having a layered crystal structure in a positive electrode active layer, thereby resulting in high safety and excellent charge / discharge capacity of the positive electrode. In addition, the positive electrode has an advantage of excellent energy density and output by including a first positive electrode active material represented by Chemical Formula 1 including three or more metals in addition to lithium.

An object of the present invention is to provide a method for producing a polymeric molded product, which enables expansion of a temperature range that can be used for partial melting. The method for producing a polymeric molded product, comprises subjecting a crystalline polyhydroxyalkanoate to a heating treatment at a temperature equal to or higher than a glass transition temperature; and melt-molding a polyhydroxyalkanoate yielded by the heating treatment, which comprises lamellar crystals that are different in lamellar thickness, in a temperature range where some of the lamellar crystals undergo melting and flowing, and the other balance lamellar crystals remain unmelted.

To provide a technique for recovering a capacity in a deteriorated positive electrode active material and reducing a reaction resistance increased by deterioration without using a means of calcination SOLUTION: According to the technology disclosed herein, a method for producing a regenerated positive electrode active material is provided. The production method includes preparing a positive electrode active material and polishing the positive electrode active material. The positive electrode active material includes a core particle having a layered crystal structure and a coating portion having a rock salt crystal structure on a surface of the core particle. In this production method, at least a part of the coating portion is separated from the core particle by polishing. The ratio (IB / IA) between the peak intensity IA at the 8341eV of the nickel (Ni) - K absorption edge measured by XAFS analysis for the positive electrode active material before polishing and the peak intensity IB at the 8341eV of the nickel (Ni) - K absorption edge measured by XAFS analysis for the positive electrode active material after polishing is 0.7 or less.SELECTED DRAWING: None

The invention relates to the technical field of nitrogen-containing graphene, in particular to a method for preparing nitrogen-containing graphene by taking chitosan as a raw material, which comprises the following steps: dissolving chitosan in an acetic acid solution with the concentration of 3-5% to form a mixed solution, uniformly coating the mixed solution on the surface of a quartz base material by adopting a spin-coating technology, and under a nitrogen protection environment, preparing the nitrogen-containing graphene by taking the chitosan as the raw material. Slowly heating the base material coated with the mixed solution to 200-3500 DEG C, and annealing for 2 hours to obtain a chitosan film; then carrying out two-step carbonization to obtain a pre-carbonized product; and uniformly mixing the obtained pre-carbonized product with a regulation agglomeration agent, carrying out two-step activation treatment, and after the activation is completed, carrying out post-treatment on the product to obtain a nitrogen-containing graphene product. The nitrogen-containing graphene prepared by the method has a D / G ratio of 0.87 and a 2D / G ratio of 0.71, has few defects and has a good layered crystal structure, and the dielectric constant of a nitrogen-containing graphene device prepared subsequently is only 3.53.

The invention discloses a high-stability rubidium-boron-silicon superhard compound and a preparation method thereof, and belongs to the technical field of superhard materials, the superhard compound is a composite structure block material formed by taking rubidium-boron-silicon as a basic framework and introducing an alkali metal regulator; the composite structure comprises a high-entropy ceramic matrix and nano twin crystals distributed in the matrix; the high-entropy ceramic matrix is a solid solution consisting of rubidium, boron, silicon and alkali metal cations introduced by the alkali metal regulator; the nano twin crystal is a lamellar crystal structure with coherent twin boundaries; through collaborative innovation of a material system and a preparation process, the rubidium-boron-silicon superhard compound with ultrahigh hardness and excellent thermal stability is developed, and a brand new solution is provided for superhard materials serving in an extremely high-temperature environment.

The present invention relates to two-phase single-crystal positive electrode materials for cycled lithium-ion batteries and methods of making the same. A method of making a positive electrode for a cycled lithium-ion battery is disclosed, as well as a battery comprising the positive electrode. In the disclosed method, single-crystal precursor particles are contacted with an aqueous solution. The precursor particles comprise a lithium-rich manganese-based transition metal oxide (LRMO) having a layered crystal structure, and the aqueous solution comprises exchangeable cations. Upon contacting the precursor particles with the aqueous solution, lithium ions are removed from an outer surface portion of the precursor particles, and the LRMO in the outer surface portion of the precursor particles is converted to a lithium-deficient manganese-based oxide (LDMO). The precursor particles are then heated such that the LDMO in the outer surface portion of the precursor particles undergoes a phase transition and is converted to a lithium manganese-based transition metal oxide having a spinel crystal structure (spinel-LMO).

The present invention discloses a lithium carbon dioxide battery with homogeneous and heterogeneous synergistic catalysis. The present invention utilizes bismuth oxyhalide / carbon paper with a layered crystal structure as a photoelectric cathode and an organic ether solvent with added halogen lithium salt as an electrolyte to enhance the light-assisted lithium carbon dioxide battery. Bismuth oxyhalide substances generate abundant electron-hole pairs under the action of the light field, which significantly reduces the difficulty of forming and decomposing Li2CO3 during the charge and discharge process. Due to the incorporation of halogen lithium salt, the photoelectric cathode is more likely to react at the solid-liquid interface, thereby enabling the photoelectric cathode to operate stably and continuously. Halogen lithium salt also helps in carrier separation, ensuring that the light-assisted lithium carbon dioxide battery maintains a low dead barrier throughout the entire cycle. The present invention significantly improves the life and stability of the photoelectric cathode through the synergistic effect of the cathode and the electrolyte, greatly reduces the difficulty of forming / decomposing the discharge product Li2CO3 during the discharge / charge process of the lithium carbon dioxide battery, reduces the overpotential of the lithium carbon dioxide battery, and improves the electrochemical performance and cycle stability of the battery.

An object of the present invention is to provide a method for producing a polymeric molded product, which does not undergo a considerable molecular weight reduction during melt-molding, even in a polymer may easily lose its molecular weight when it is in a melted state. The present invention provides a method for producing a polymeric molded product, which comprises melt-molding a polymer comprising lamellar crystals that are different in lamella thickness, in a temperature range where some of the lamellar crystals undergo melting and flowing, and the other balance lamellar crystals remain unmelted.

The invention relates to a method for preparing negative electrode regenerated graphite from waste graphite, and the method comprises the following steps: mixing a waste graphite negative electrode with a vulcanizing agent, and carrying out primary impurity removal to obtain graphite; oxidizing and acid-leaching the graphite to obtain a leaching solution and leaching residues; the leached residues are sequentially subjected to first acid leaching and second acid leaching, and high-purity graphite is obtained; the high-purity graphite is subjected to coating modification and carbonization regeneration, and the negative electrode regenerated graphite is obtained. According to the method, the vulcanizing agent is adopted for impurity removal, impurities in the waste graphite negative electrode can be deeply removed, and finally high-purity graphite with the purity reaching 99.95% or above is obtained; meanwhile, the whole recovery process has small damage to the layered crystal structure of the graphite, the original complete graphite structure can be maintained, the problem of electrochemical performance degradation caused by insufficient graphite purity or structural damage in a traditional recovery method is solved, and the negative electrode regenerated graphite meets the requirements of a lithium ion battery negative electrode material with high capacity and long cycle life.

The invention discloses a preparation method of a two-dimensional non-layered crystal, which comprises the following steps: uniformly mixing raw material powder of target products TiO2, CdS and PbS with cosolvent powder to serve as reaction raw materials, taking a silicon wafer or sapphire as substrates, clamping the reaction raw materials between two substrates, putting the substrates into a CVD (Chemical Vapor Deposition) tubular furnace device to enable the reaction raw materials to fully react, and preparing the target products on the substrates. According to the preparation method, the reaction raw materials are melted into liquid by using an evaporation method and are naturally cooled to normal temperature, the TiO2, CdS and PbS films are prepared on the silicon wafer or the sapphire substrate, and the method is simple in operation process, short in growth cycle, low in cost and good in growing crystal quality.

A positive electrode active material includes secondary particles in each of which primary particles are aggregated, wherein each of the secondary particles is a lithium transition metal composite oxide having a lamellar crystal structure. The lithium transition metal composite oxide includes Li, Ni, Mn, Co, and M, and a molar ratio of the Li, the Ni, the Mn, the Co, and the M is Li:Ni:Mn:Co:M=a:x:y:z:t, where the M, the a, the x, the y, the z, and the t are defined as in the scope of claims for patent. An integrated intensity ratio (I003 / I104) of diffraction peaks of the secondary particle in an X-ray diffraction method is 1.05 to 1.19. A crystallite size Loos of the secondary particle is 1000 Å or more.

The application provides a natural tetrapeptide-based MOF material and a preparation method thereof. The natural tetrapeptide-based MOF material is assembled by a tetrapeptide, amino-glycine-histidine-glycine-glycine-carboxyl (GHGG) as a ligand and a divalent copper ion, and is abbreviated as Cu-GHGG, wherein the molar ratio of the ligand to the divalent copper ion is 1:1. The Cu-GHGG prepared by the application is a layered crystal, and the crystallization solvent is filled between layers during crystallization. After the crystallization solvent is removed by heating, the material still maintains crystallinity. The material after removal of the solvent can adsorb water molecules in the air by itself when placed in humid air.

The invention discloses a gamma ray shielding material with sedimentation resistance and a preparation method and application thereof, and belongs to the technical field of shielding materials. The composite material sequentially comprises hollow glass beads, an epoxy bonding layer and a lead and lead compound coating from inside to outside. The thickness of the epoxy bonding layer is 10-50 nm, the surface coverage rate of the heavy metal plating layer reaches 85% or above, the particle size distribution of the hollow glass beads is 10-80 microns, and the overall density of the composite material is 2.8-3.5 g / cm < 3 >. The lead and lead compound plating layer comprises sheet-shaped crystal structures growing in a staggered mode, the transverse size of a single nanosheet is 0.5-5 micrometers, and a continuous net-shaped shielding structure is formed between adjacent nanosheet layers. The lead-plated hollow glass bead has a uniform and compact lead plating layer, so that the lead-plated hollow glass bead has remarkable advantages in the performance of a composite material. By using the lead-plated hollow glass beads, the density of the composite material is effectively reduced, the gamma-ray shielding capability of the composite material is improved, and dual optimization of light weight and efficient shielding performance is successfully realized.

The application belongs to the field of conductive silver paste, and particularly relates to a low-resistance wear-resistant conductive silver paste and a preparation method thereof. The preparation method is as follows: the silver paste of the application is a synergistic combination of flaky silver powder and nano silver material, the flaky silver powder forms a main conductive framework in the coating to ensure the basic conductive path, the nano silver material produces local fusion at the silver powder contact interface during solidification, effectively fills the micro pores, and significantly reduces the contact resistance between the particles. Ultra-fine hard ceramic particles subjected to surface treatment are additionally added, which are uniformly dispersed in the coating after solidification, bear and resist external force scratching. Meanwhile, solid lubricating materials with a layered crystal structure are introduced, which can form a transfer film on the contact surface during friction, convert sliding friction into low-resistance shearing between the layers, thereby reducing the wear rate from the root cause, and exhibiting excellent electrical stability and mechanical durability.

Disclosed are positive electrode active materials and rechargeable lithium batteries including the positive electrode active materials. The positive electrode active materials comprise a first particle including a first lithium composite oxide having a spinel crystal structure, a second particle including a second lithium composite oxide having a layered crystal structure, and a third particle including a third lithium composite oxide having a layered crystal structure. An average particle diameter of the second particle is greater than an average particle diameter of the third particle. The first particle has a first weight ratio relative to a total weight of the first, second, and third particles. The second particle has a second weight ratio relative to the total weight. The third particle has a third weight ratio relative to the total weight. The first weight ratio is greater than a sum of the second weight ratio and the third weight ratio.

The invention provides a positive electrode material and a preparation method thereof, a positive plate and a battery. The positive electrode material comprises an inner core and a coating layer, the inner core comprises nickel cobalt lithium manganate, the chemical formula of the nickel cobalt lithium manganate is LiNi < x > < 1 > Mn < y > < 1 > Co < z > < 1 > O < 2 >, and x < 1 > + y < 1 > + z < 1 > = 1, and 0 lt; z1 < = 0.05; the coating layer comprises lithium nickel manganese oxide, the chemical formula of the lithium nickel manganese oxide is LiNix2Mny2O2, x2 + y2 = 1, and x2 is greater than or equal to 0.5 and less than or equal to 0.9; according to the invention, the coating layer is set to be cobalt-free lithium nickel manganese oxide, so that the coating layer has higher thermal decomposition temperature and more stable interface characteristics, and the safety performance of the battery is improved; the lithium nickel cobalt manganese oxide is adopted in the inner core, the cobalt content is low, positive ion mixing can be effectively inhibited, a layered crystal structure is stabilized, the high capacity and the ion migration rate of the material are guaranteed, meanwhile, the inner core is protected by the shell, side reaction with electrolyte is reduced, and therefore the cycle life is remarkably prolonged; according to the method, the cost of raw materials is greatly reduced, the dependence on scarce cobalt resources is reduced, and the sustainable development requirement is met.

The invention provides an oxidation-resistant core-shell structure powder material as well as a preparation method and application thereof, and belongs to the technical field of solid lubricating materials and tribological engineering. According to the oxidation-resistant core-shell structure powder material, MoS2 microparticles are used as an inner core, and a polyvinylidene fluoride polymer is used as a shell layer. The vinylidene fluoride polymer is used as a shell of the molybdenum disulfide, so that water molecules and oxygen can be prevented from being in direct contact with the molybdenum disulfide, the barrier and protection effects are achieved, an easily-sliding layered crystal structure of MoS2 is kept, the molybdenum disulfide is prevented from being oxidized into molybdenum trioxide, the oxidation resistance of the molybdenum disulfide in different environments is effectively improved, and the service life of the molybdenum disulfide is prolonged. The molybdenum disulfide microparticles prepared by the preparation method disclosed by the invention have the advantages that the storage life of the molybdenum disulfide microparticles is prolonged, the environmental dependence and sensitivity in lubrication application are reduced, and the molybdenum disulfide microparticles can adapt to different environmental atmospheres and still have lower friction coefficient and wear volume than a single-component material in a high-humidity environment. And the synergistic lubrication effect is achieved.

A method for manufacturing an abradable layer and a substrate coated with this layer, may include: preparing a powder composition including at least ceramic particles and an inorganic filler having a lamellar crystallographic structure, the volume content of the inorganic filler in the powder composition being in a range of from 1 to 75%; compressing the powder composition; and sintering the powder composition thus compressed in order to obtain the abradable layer.

The present disclosure relates to a method for manufacturing a regenerated positive electrode active material. Provided is a technique for restoring the capacity in a degraded positive electrode active material and reducing the reaction resistance increased due to degradation without using a firing means. According to the technology disclosed herein, a method for producing a regenerated positive electrode active material is provided. The manufacturing method comprises the following steps: preparing a positive electrode active material; and grinding the positive electrode active material. The positive electrode active material includes a core particle having a layered crystal structure, and a coating portion having a rock salt crystal structure on the surface of the core particle. In this production method, at least a portion of the coated portion is separated from the core particles by grinding. The ratio (IB / IA) of the peak intensity IA at 8341 eV of the nickel (Ni)-K absorption edge as measured in XAFS analysis of the positive electrode active material before polishing to the peak intensity IB at 8341 eV of the nickel (Ni)-K absorption edge as measured in XAFS analysis of the positive electrode active material after polishing is 0.7 or less.

The application belongs to the field of solid waste resource utilization and electrochemical energy storage technology, and more particularly relates to a solid electrolyte based on waste cement paste as well as a preparation method and application thereof. Through directional conversion reaction between calcium-silicon-aluminum hydration phase in waste cement paste and zinc sulfate solution, a gypsum-alkali zinc sulfate composite phase (ZnCP composite material) with a layered crystal structure is in-situ constructed, and a collaborative breakthrough of high-value recycling of waste resources and development of high-performance solid electrolyte is realized. The structure-performance synergistic mechanism of the ZnCP composite material makes the solid electrolyte provided by the application maintain excellent electrochemical stability in a wide temperature range of-20-60 DEG C, the Zn / / polyaniline full battery assembled has a cycle life of more than 420 times, and the zinc / / zinc symmetric battery is stably operated for more than 1500 hours without dendrite and hydrogen evolution.

Provided is a positive electrode that can provide a nonaqueous electrolyte secondary battery with high gas generation suppressing performance during storage and high cycle characteristics. The positive electrode disclosed here includes a positive electrode current collector and a positive electrode active material layer supported by the positive electrode current collector. The positive electrode active material layer includes monoparticulate first Ni-containing lithium composite oxide particles and secondary particulate second Ni-containing lithium composite oxide particles. The first Ni-containing lithium composite oxide particles and the second Ni-containing lithium composite oxide particles have layered crystal structures. The first Ni-containing lithium composite oxide particles have an average particle size (D50) of 2 μm to 6 μm. The second Ni-containing lithium composite oxide particles have an average primary particle size of 1.2 μm to 2.0 μm. The second Ni-containing lithium composite oxide particles have an average particle size (D50) of 12 μm to 20 μm.

A catholyte destined to be used in a lithium ion solid-state battery, said catholyte comprising: (i) a solid electrolyte powder having a formula: Li(3.5+L+x)Si(0.5+s−x)P(0.5+p−x)Ge2xO4+a, wherein −0.10≤L≤0.10, −0.10≤s≤0.10, −0.10≤p≤0.10, −0.40≤a≤0.40, and 0.00≤x≤0.30, and (ii) a positive electrode active material powder having a formula: Li1+kM′1−kO2 where M′=Ni1−x′−y−z′Mnx′Coy′Az′ with −0.05≤k≤0.05, 0≤x′≤0.40, 0.05≤y′≤0.40, and 0≤z′≤0.05, wherein A is a doping element which is different to Li, M′ and O, said positive active material powder comprising particles having a layered R-3m crystal structure, said catholyte having a D99≤50 μm and an ionic conductivity of at least 1.0×10−6 S / m.