121 results about "Potassium-ion battery" patented technology

The invention relates to a method for preparing a hard carbon material from carbon dot heterogeneous cross-linked bituminous coal, a coal-based hard carbon material and application. The preparation method comprises the following steps: (1) soaking pretreated bituminous coal in an acid solution, washing to be neutral, and drying to obtain dry pulverized coal; (2) dispersing the carbon dots in an alcohol solvent for ultrasonic treatment to obtain a dispersion liquid; (3) mixing the dried pulverized coal obtained in the step (1) and the dispersion liquid obtained in the step (2), mechanically stirring, and drying to obtain a mixture; (4) performing low-temperature heating crosslinking on the mixture obtained in the step (3) in an oxygen-containing atmosphere so as to obtain a heterogeneous crosslinking product; and (5) performing high-temperature carbonization on the heterogeneous cross-linked product in an inert atmosphere to obtain the coal-based hard carbon material. The coal-based hard carbon material can be used as a sodium ion battery / potassium ion battery negative electrode, and has excellent sodium / potassium storage performance.

The invention discloses a tellurium-doped sulfurized polyacrylonitrile potassium storage negative electrode material and a potassium ion total battery, and belongs to the field of potassium ion batteries. In order to solve the technical problems of low sulfur utilization rate and poor rate capability when sulfurized polyacrylonitrile is used as a potassium storage negative electrode material, the tellurium-doped sulfurized polyacrylonitrile (Te-SPAN) material with high performance is synthesized in a tellurium doping manner. In the tellurium-doped sulfurized polyacrylonitrile (Te-SPAN), the content of tellurium is lower than 5%, the content of sulfur is 33%-39%, and the content of carbon is 59%-62%. When the Te-SPAN is used as a potassium storage negative electrode material, the Te-SPAN shows high potassium storage capacity, excellent rate capability and cycling stability. In addition, the potassium ion total battery assembled based on the composite negative electrode and the low-defect manganese potassium hexacyanoferrate positive electrode also shows very excellent electrochemical performance.

The invention discloses a potassium ion battery positive electrode material and a preparation method and application thereof, the chemical general formula of the positive electrode material is Kw [MnxFeyCuzMgaZrbAlc] O2, in the formula, 0.40 < = w < = 0.50, 0.75 < = x < = 0.85, 0.02 < = y < = 0.06, 0.02 < = z < = 0.06, 0.02 < = a < = 0.06, 0.02 < = b < = 0.06, and 0.02 < = c < = 0.06; x + y + z + a + b + c = 1.

The invention discloses a modified hard carbon material, a preparation method thereof and a battery, and relates to the technical field of battery negative electrode materials. The preparation method comprises the following steps: forming a hard carbon layer by taking grafted silicon dioxide as a template, coating the hard carbon layer with a soft carbon layer, coating the soft carbon layer with silicon dioxide, performing confinement carbonization, and removing the template. Wherein the grafted silicon dioxide contains hetero atoms S, and the hard carbon layer contains hetero atoms P. During preparation, a silicon dioxide template grafted with 3-mercaptopropyltriethoxysilane is prepared by a reverse micelle method, a phenolic resin precursor is coated to form the hard carbon layer, P is introduced through modification of triglycidyl phosphate, then an asphalt-based soft carbon layer is coated, and carbonization is performed to obtain the modified phenolic resin. And removing silicon dioxide to obtain the target material. According to the material, active sites and interlayer spacing are increased through precise doping of S and P, volume expansion is relieved through cooperation of soft carbon and hard carbon, ion adsorption is enhanced through oxygen groups, and the material shows high capacity and excellent cycle stability in secondary batteries such as potassium ions and the like and is suitable for the field of novel energy storage batteries.

The present invention relates to the synthesis of pure metal or multi-metal derivatives of ZIF-11, ZIF-12 or amorphous ZIF structures in high yield followed by calcination under inert conditions to produce in composite nanostructures one or more metal selenide dispersed on the surface of or embedded in a carbon matrix, and using these composites as electrodes for lithium ion batteries, sodium ion batteries, potassium ion batteries, supercapacitors or fuel cells.

The invention belongs to the field of organic electrolytes and potassium ion batteries, and particularly relates to a low-concentration ionic liquid electrolyte for breaking the concentration balance of potassium ions and anions and a high-energy-density potassium ion battery. The potassium ion battery comprises a Prussian blue (PB) positive electrode, an electrolyte and a commercial ferrocene (Fc) negative electrode which is not subjected to any treatment, and the electrolyte is a low-concentration ionic liquid electrolyte (FSI-: K + (3.5 / 0.3 M)) of potassium bis (fluorosulfonyl) imide (KFSI). The low-concentration ionic liquid electrolyte developed by the invention has a high anion: K < + > concentration ratio (3.5: 0.3 M), increases the solvation proportion of rich anions, reduces the dissolution of an Fc organic metal compound, and ensures high interface stability and rapid K < + > storage kinetics of an Fc negative electrode. Meanwhile, the electrochemical window of the low-concentration electrolyte is widened, the PB positive electrode can stably circulate at 1.0-4.4 V, the long-period circulation and excellent rate capability of the PBFc total battery are also realized, and the total battery has the energy density of 246.7 Wh / kg under the current density of 20 mA / g.

The application discloses a modified hard carbon material and a preparation method and a battery thereof, and relates to the technical field of battery negative materials. The hard carbon layer is formed by using grafted silica as a template, then the soft carbon layer is coated outside the hard carbon layer, and then the silica is coated outside the soft carbon layer to limit carbonization and remove the template to obtain the target material; wherein the grafted silica contains a heteroatom S, and the hard carbon layer contains a heteroatom P; in the preparation, the silica template grafted with 3-mercaptopropyl triethoxysilane is prepared by a reverse micelle method, the phenol formaldehyde resin precursor is coated to form the hard carbon layer, P is introduced by modification of the trisglycidyl phosphate, and then the pitch-based soft carbon layer is carbonized, and then the silica is removed to obtain the target material. The material increases the active sites and the interlayer spacing by accurate doping of S and P, cooperatively relieves the volume expansion by the hard and soft carbons, and strengthens the ion adsorption by the oxygen groups, and exhibits high capacity and excellent cycle stability in the secondary batteries such as potassium ion batteries, and is suitable for the field of new energy storage batteries.

The invention belongs to the technical field of battery positive electrode material preparation, and particularly relates to a cross-linked conjugated polymer, a preparation method and application in an alkali metal battery. When the cross-linked conjugated polymer is used as a positive electrode, the cross-linked conjugated polymer shows excellent performance in lithium, sodium and potassium ion batteries: the average discharge voltage is as high as 3.4-3.5 V, which is beneficial for improving the energy density of the battery; under extremely high current density, high capacity exceeding 120mAh. G <-1 > can still be released, and extremely fast dynamic characteristics are shown; and under the harsh test condition, the capacity retention ratio still reaches up to 85%-90%.

The application discloses a flower ball-shaped bismuth disulfide / tungsten disulfide composite material and a preparation method and application thereof. Tungsten hexachloride is added into anhydrous ethanol solution and fully stirred, then bismuth nitrate pentahydrate is added into the mixed solution and stirred to uniformly disperse the bismuth nitrate pentahydrate into the solution, then thioacetamide is added and stirred to be uniform, the obtained solution is moved into a reaction kettle, and the reaction kettle is sealed and placed into a homogeneous reactor; after the reaction is completed, the product is taken out, washed and fully dried in a vacuum oven to obtain the composite material. The composite material has a thickness of 20-30 nm, and nanosheets are vertically grown on a self-assembled flower ball-shaped structure with a diameter of 350-400 nm; the composite material can be applied to preparation of a potassium ion battery negative electrode material, and the structure is more stable, the conductivity is better, and the electrochemical performance is greatly improved.

The invention discloses a bismuth-antimony-tin alloy negative electrode material of a potassium ion battery and a preparation method of the bismuth-antimony-tin alloy negative electrode material, and belongs to the technical field of new energy. The preparation method comprises the following steps: firstly, obtaining bismuth-antimony-tin alloy precursor powder by adopting an oil bath evaporation drying method, then putting the bismuth-antimony-tin alloy precursor powder into a tubular furnace, carrying out heat treatment under a protective atmosphere, and washing and drying to obtain the bismuth-antimony-tin-carbon composite material. The middle entropy property of the ternary alloy enables the structural stability of the material to be improved, three-dimensional carbon coating can relieve volume expansion of alloy particles in the circulation process, and the circulation stability of the composite material is improved.

The application relates to a high-conductivity double-carbazole type two-dimensional conductive metal organic framework material, a preparation method and application thereof, and belongs to the field of metal organic framework materials. Three double-carbazole type two-dimensional conductive metal organic framework materials Cu-DCA-MOF, Cu-DCPy-MOF and Cu-DCPt-MOF are prepared, all of which have a special "rotor-stator" structure, and are obtained by coordination polymerization of double-carbazole type ligands and metal ions. Due to the special "rotor-stator" structure of the double-carbazole type ligands, the three materials have high crystallinity and high conductivity, and have important significance in enriching the types and structural diversity of two-dimensional conductive metal organic framework materials. In addition, the double-carbazole type two-dimensional conductive metal organic framework materials with high conductivity can be applied in potassium ion batteries, and provide a new idea and solution for the development of positive electrode materials of the potassium ion batteries.

The invention relates to an in-situ polymerization cross-linked battery adhesive as well as a preparation method and application thereof, and belongs to the technical field of electrode materials. The technical problems that a traditional linear adhesive is low in mechanical strength, poor in high-temperature stability and prone to swelling in electrolyte, and an existing crosslinking technology is complex in process and incompatible with an existing production line are solved. The invention provides an adhesive. A polyamino compound and polyethylene glycol with multiple epoxy end groups are spontaneously subjected to a ring-opening polymerization reaction through amino groups and epoxy groups, and a three-dimensional cross-linked polyether-amine network structure is formed in situ. The method is simple in process and compatible with a conventional electrode drying process. A cross-linked network formed by the adhesive endows the electrode with excellent mechanical strength and stripping resistance, and active substances can be effectively inhibited from falling off; and meanwhile, the high thermal stability and the insolubility in electrolyte are realized, so that the cycle life and the safety of lithium ion, sodium ion and potassium ion batteries are remarkably prolonged, and the safety of the lithium ion, sodium ion and potassium ion batteries is remarkably improved.

The invention discloses a pomegranate-shaped core-shell structure tin pyrophosphate negative electrode material as well as a preparation method and application thereof, and belongs to the technical field of electrochemical energy storage materials. The preparation method comprises the following steps: mixing tetravalent tin salt and a phosphonic acid organic ligand, and carrying out hydrothermal reaction to obtain a tin-based metal organic framework precursor; the phosphonic acid organic ligand is selected from one or two of phenylphosphonic acid or (pyridine-2-yl methyl) phosphonic acid; and carrying out heat treatment on the tin-based metal organic framework precursor at 550-700 DEG C to obtain the pomegranate-shaped core-shell structure tin pyrophosphate negative electrode material. The tetravalent tin salt and the specific phosphonic acid ligand are used for constructing the precursor, and the Kirkendall effect in the pyrolysis process is utilized to form a unique core-shell structure, so that the negative electrode material shows excellent cycling stability under high current density when being used for the potassium ion battery or the sodium ion battery.

Provided is a cathode active material for a rechargeable alkali metal battery, wherein the cathode active material comprises a sodium salt composite comprising a mixture or composite of Fe and at least a sodium salt selected from NaxA, wherein x is from 1 to 3, and the anion Ax− is selected from F−, Cl−, Br−, I−1, PO43−, SO42−, CO32−, SiO32−, NO3−, B4O72−, or a combination thereof, wherein a molar ratio of Fe-to-sodium salt is from 1 / 9 to 9 / 1. Also provided is a rechargeable alkali metal battery comprising this cathode active material, which is a sodium battery (sodium-ion or sodium metal battery), a lithium battery (lithium-ion or lithium metal battery), or a potassium battery (potassium-ion or potassium metal battery).

The application discloses a novel Na2MnFe(CN)6 material and application thereof as a lithium ion battery, a sodium ion battery, a potassium ion battery, a magnesium ion battery, a zinc ion battery and a zinc-sodium dual-ion battery positive electrode material, wherein the Na2MnFe(CN)6 material is an inorganic material. The excellent electrochemical performance of the novel Na2MnFe(CN)6 material in the application indicates that the novel Na2MnFe(CN)6 material has a very large application prospect as the lithium ion battery, the sodium ion battery, the magnesium ion battery, the zinc ion battery and the zinc-sodium dual-ion battery positive electrode material. Meanwhile, the novel Na2MnFe(CN)6 material has a simple and controllable preparation process, and a simple device, and is a method easy to mass produce.

The invention relates to the technical field of energy storage, in particular to a sulfur-doped interconnected hollow porous composite carbon nano-microsphere, a preparation method and application of the sulfur-doped interconnected hollow porous composite carbon nano-microsphere. According to the invention, resorcinol-formaldehyde resin and coal pitch are used as carbon sources, and sublimed sulfur is used as a sulfur source; the preparation method comprises the following steps: uniformly mixing resorcinol-formaldehyde resin, coal pitch and sublimed sulfur, putting the mixture into a carbonization furnace, and heating in an argon atmosphere to prepare the sulfur-doped interconnected hollow porous composite carbon nano-microspheres. The specific surface area of the hollow porous composite carbon nanospheres is 230-390 m < 2 > / g; the total pore volume is between 0.16 cm < 3 > / g and 0.38 cm < 3 > / g; as a negative electrode material of a potassium ion battery, in a 1.0 M potassium bis (fluorosulfonyl) imide (KFSI) electrolyte, when the current density is 0.1 C, the specific capacity reaches 394.6 mAh / g; and when the current density is 5C, the capacity is kept at 200.6 mAh / g after circulation is carried out for 1 to 500 times. When the current density is increased to 20C, the specific capacity can reach 140.4 mAh / g, and high capacity and good rate capability are shown.

The invention discloses a sodium manganate positive electrode material with an interlayer stacking structure as well as a preparation method and application of the sodium manganate positive electrode material. The sodium manganate positive electrode material has an ABB 'C' ABB 'C' type oxygen layer stacking sequence, Mg < 2 + > ions specifically occupy twisted triangular prism sites in an alkali metal sodium layer, and P type and O type NaO6 coordination polyhedrons exist in a crystal structure of the material at the same time. Through a composite three-step synthesis process of'sol-gel-solvothermal-solid phase method ', the thermodynamic tendency that conventional magnesium ions occupy a transition metal layer is effectively broken, and synergistic distortion of prismatic interstitial sites is realized, so that a brand new symmetric structure different from a traditional P phase and a traditional O phase is constructed. According to the positive electrode material disclosed by the invention, unfavorable phase transformation in the charging and discharging process is remarkably relieved through a special lattice stacking structure, the positive electrode material has high capacity and long cycle life, and a new thought is provided for the design of a high-energy-density sodium or potassium ion battery.

This invention discloses a SnS / WS2@C composite electrode material, its preparation method, and its application, belonging to the field of tungsten disulfide nanomaterials technology. A precursor solution A is obtained by uniformly dispersing SnCl2·2H2O and CH3CSNH2 in anhydrous ethanol. After a solvothermal reaction, precursor solution A is cooled, centrifuged, washed, and freeze-dried to obtain powder B. Powder B, WCl6, and CH3CSNH2 are uniformly dispersed in anhydrous ethanol to obtain solution C. After a solvothermal reaction, solution C is cooled, centrifuged, washed, and freeze-dried to obtain powder D. Powder D is uniformly dispersed with glucose in deionized water to obtain precursor solution E. After a solvothermal reaction, precursor solution E is cooled, centrifuged, washed, and freeze-dried to obtain powder F. Powder F is calcined at high temperature to obtain the SnS / WS2@C composite electrode material. Performance testing of the prepared SnS / WS2@C composite electrode material revealed that it exhibits good electrochemical performance when used as a negative electrode in potassium-ion batteries.

The application provides a potassium ion battery positive electrode active material, a positive electrode material and a preparation method and application thereof. x A 1‑y‑z B y C z O 2‑m F m , 0 < x < 1, 0 <= y <= 0.5, 0 <= z <= 0.5, 0 <= m <= 0.5, and m and y, z are not 0 at the same time; A is selected from at least one of Co and Mn; B is selected from at least one of Zn, Ni, Mg and Cu; and C is selected from at least one of Cr, Fe, Ti and Li. The potassium ion battery positive electrode material prepared by using the positive electrode active material provided by the application can effectively solve the problems of unstable structure, complex phase change and capacity attenuation of the K x AO2 type potassium ion battery positive electrode material, and the positive electrode active material has wide application prospect and advantages. The potassium ion battery provided by the application is expected to be a new type of energy storage device, is suitable for large-scale energy storage equipment, and has good commercial application prospect.

The present application relates to the technical field of positive electrode materials, and in particular to a positive electrode material, and a preparation method therefor and a use thereof. The molecular formula of the positive electrode material is K0.5MnxMgyOzF2-z, wherein x is greater than 0 and less than 1.0, y is greater than 0 and less than 1.0, z is greater than 0 and less than 2, and x+y=1. Substitution of O2- with F- can expand the interlayer spacing of K0.5MnO2(KMO) and inhibit release of lattice O, and this change facilitates rapid transformation of K+ ions without causing substantial damage to the structure. In addition, by increasing the average valence state of manganese, introduction of Mg2+ and F- ions can effectively inhibit Jahn-Teller distortion. The cation and anion doping method enables the reversible capacity of the KMMOF cathode to reach up to about 110 mAhg-1 (at a current of 100 mAg-1), and a prepared potassium-ion battery has good cycle performance and rate capability.

This invention discloses a method for preparing a tightly connected FeS2 hollow sphere@graphene microstructure: S1, ferric nitrate and alcohol are mixed and reacted to obtain a Fe-alcohol complex; S2, dopamine hydrochloride is added to the Fe-alcohol complex, and a polymerization reaction is carried out by stirring; after the polymerization reaction, a cationic surfactant is added; S3, the product obtained in S2 is added to a graphene oxide dispersion, and the reaction is stirred; S4, the product obtained in S3 is calcined for the first time, and sulfur powder is added for the second calcination to obtain a tightly connected FeS2 hollow sphere@graphene microstructure. This invention also provides the tightly connected FeS2 hollow sphere@graphene microstructure obtained by the above preparation method and its application in the anode of potassium-ion batteries. This preparation method achieves a tight connection between FeS2 hollow spheres and graphene, solving the problems of poor electronic conductivity and structural stability of micron-sized FeS2, and achieving excellent rate performance when applied to the anode of potassium-ion batteries.

A carbon composition useful as a sodium-ion battery anode material, the composition comprising an amorphous carbon material containing randomly oriented graphene platelets along with the following additional features: (i) nanovoids contoured by layers of the graphene platelets, wherein the nanovoids have a size of 2-20 nm; (ii) sub-nanopores that traverse said layers and having a size of 0.2-0.6 nm; and (iii) microchannels connecting between said nanovoids, wherein said microchannels have a width less than 2 nm Further described herein are sodium-ion and potassium-ion batteries containing the carbon composition incorporated into an anode of the battery. Further described herein is a method for producing the carbon composition by gradual heating of a carbonaceous precursor material such as biomass or plastic waste.

The invention relates to the technical field of new energy storage, in particular to a bromine-modified high-rate graphite negative electrode material and a preparation method thereof. The bromine-modified high-rate graphite negative electrode material comprises graphite and a specific bromine modifier, and in the bromine-modified high-rate graphite negative electrode material and the preparation method thereof, the bromine-modified high-rate graphite negative electrode material is obtained by adding the specific bromine modifier and optimizing a preparation process. When the negative electrode material is applied to the potassium ion battery, graphite and a specific bromine modifier can form a stable composite structure, and high-magnification performance is realized. The material is simple in preparation process and easy to operate; raw materials are easy to obtain, reaction equipment is relatively simple, and the application prospect is relatively great.

The invention discloses a rubber waste-derived carbon-based negative electrode material and a preparation method and application thereof, and belongs to the technical field of preparation of negative electrode materials, the rubber waste is firstly cleaned, subjected to impurity removal and crushed, and then subjected to pre-oxidation treatment, coating treatment, secondary sintering treatment, carbonization and acid treatment to remove inorganic impurities, and the carbon-based negative electrode material is prepared. The prepared rubber waste derived carbon-based negative electrode material is rich in O element, the electronegativity introduced by O atoms improves the surface adsorption capacity of hard carbon, increases the number of internal defects and improves the storage capacity of alkali metal ions, and a coating material forms a highly graphitized compact structure on the surface of a block material, so that the long cycle stability is improved; as a negative electrode material of lithium, sodium and potassium ion batteries, the material has the characteristics of high cycling stability, high reversible specific capacity, high energy density and high rate capability, is used for large-scale energy storage application, is simple in process, short in period, high in repeatability and convenient for batch production, and has an excellent industrial prospect.

A method for producing a positive electrode (10) with a current collector (12) and a positive active material (18) applied to the current collector (12) for a sodium ion battery or a potassium ion battery comprises a step in which the positive active material (18) is coated in solution with a coating (20) of a polythiophene. Furthermore, a positive electrode and a battery are specified.

The invention discloses a WOx-WS2 metal-ligand composite material and a preparation method and application thereof, and belongs to the technical field of potassium ion battery motor materials.The preparation method comprises the steps that an ethanol solution of 2-methylimidazole is added into an ethanol solution of a tungsten source, stirring reaction is conducted, solvothermal reaction, washing, vacuum drying and heat treatment are conducted, WOx is obtained, and the WOx-WS2 metal-ligand composite material is obtained. And performing vulcanization reaction on the WOx and a sulfur source in an inert gas environment to obtain the WOx-coated WS2 metal-ligand composite material. The prepared product has a unique metal-ligand structure, can provide more active sites for storage of K < + > in the charge-discharge process, and enhances the storage capacity of K < + >, so that the material can show relatively high capacity. The insertion capability and the storage speed of potassium ions in the electrode material are remarkably improved, so that the electrode material can show excellent rate capability. The synthesis temperature is low, and the synthesis path and reaction conditions are simple; the reaction is easy to control, post-treatment is not needed, and the method is environment-friendly and suitable for large-scale production.

This invention discloses a molybdenum phosphide quantum dot-embedded polyaniline-derived hollow sphere hard carbon composite material and its preparation method. The preparation method includes the following steps: (1) preparing polyaniline hollow spheres using aniline, hydrogen peroxide, anhydrous ferric chloride, and phosphoric acid aqueous solution as raw materials via a hydrothermal method; (2) immersing the polyaniline hollow spheres in concentrated hydrochloric acid, drying them, and then performing a secondary hydrothermal treatment with ammonium molybdate tetrahydrate and ammonium dihydrogen phosphate to obtain a precursor; (3) further carbonizing and phosphating the precursor with sodium hypophosphite monohydrate to obtain the molybdenum phosphide quantum dot-embedded polyaniline-derived hollow sphere hard carbon composite material. In this composite material, molybdenum phosphide is embedded in the hard carbon wall of polyaniline hollow spheres with a diameter of 200-300 nm in the form of 2-3 nm quantum dots, accounting for approximately 20-25 wt% by mass. The composite material provided by this invention can be used as an electrode material, and the potassium-ion batteries prepared from it have high specific capacity, good cycle stability, and excellent rate performance. Furthermore, the method provided by this invention has the advantages of simple process, low cost, and large-scale production capability.

The present application relates to a kind of mesoporous hard carbon coated Fe3C@SiO2 Composite material preparation method and its application. With ferrous oxalate as raw material, precursor is obtained by using sol-gel method and hydrothermal method combined method, and mesoporous hard carbon coated Fe3C@SiO2 Composite material is obtained by calcining under inert gas protection.The mesoporous hard carbon coated Fe3C@SiO2 Composite material of the present application is applied to the negative electrode material of sodium ion battery and potassium ion battery, and has good electrochemical performance, provides good foundation for the future development of sodium ion battery and potassium ion battery.

The invention provides an induced preparation method of a positive electrode material of a Prussian blue potassium ion battery. The method comprises the following steps: S1, dissolving cyanide salt in deionized water to form a solution A; s2, dissolving ferrite, a complexing agent and an acid-base regulator in deionized water to form a solution B, and adding a nucleation template to induce crystallization after the solution B is uniformly mixed; s3, under the protection of inert atmosphere, slowly adding the solution A obtained in the step S1 into the solution B obtained in the step S2, continuously stirring to react, and then carrying out preliminary centrifugation to obtain solid powder; and S4, putting the solid powder obtained in the step S3 into a graphite mold, and removing crystal water through Joule heating to obtain the Prussian blue positive electrode material. The complexing agent and the nucleation template are used for inducing slow and ordered crystallization, crystal water is removed through rapid heating, crystal boundary slippage is avoided, the material stability is improved, the preparation method is simple, convenient and efficient, the yield is high, and the reaction is easy to control.

The invention belongs to the field of organic electrolyte and potassium ion batteries, and particularly relates to a high-energy-density potassium ion battery realized by medium-entropy electrolyte applicable to an alloy antimony / conductive carbon negative electrode. The potassium ion battery comprises a Prussian blue (PB) positive electrode, an electrolyte and an antimony / conductive carbon (Sb / SP) negative electrode, and the electrolyte is a medium-entropy electrolyte of potassium bis (fluorosulfonyl) imide (KFSI). The obviously improved rate performance of the medium-entropy electrolyte and the Sb / SP developed by the invention is attributed to a balance solvation structure driven by a double-entropy effect and a weak solvation effect, and the structure provides a collaborative guarantee for enough interface stability and dynamic compatibility. Meanwhile, the electrochemical window of the ether-based electrolyte is widened, the PB positive electrode can stably circulate at 2.0-4.4 V, and the PBMSESb / SP total battery can achieve the high energy density of 194 Wh / kg under the current density of 50 mA / g (based on the total mass of PB and Sb / SP).