Polyanion compound KTi2(PO4)3, preparation of carbon coating thereof and application of product of polyanion compound KYi(PO4)3

Abstract

The invention discloses a polyanion compound KYi(PO4)3, a preparation method of a carbon coating thereof and application of a product of the polyanion compound KYi(PO4)3 and the polyanion compound KYi(PO4)3 as a potassium ion battery electrode material. The method has the advantages that operation is easy and convenient, a solvothermal method is adopted, and synthesis is easy; the reaction temperature is low, reactions are mild, and the yield is high; raw materials are TiO2, KH2PO4.2H2O, H3PO4 and deionized water with the stable chemical properties, and the cost is low; no harmful gas is generated in the reaction process, and no pollution is caused. Various methods show that the product is uniform in morphology, the phase is pure, and no impurity is generated. The KYi2(PO4)3 and KTi2(PO4)3 / C with the nanoscale cube structures are applied to a potassium ion battery, and tests show that the electrochemical performance of the potassium ion battery is good, and the electrochemical performance of KTi2(PO4)3 / C is better.

Description

technical field

[0001] The invention belongs to the field of potassium ion battery materials, in particular to a polyanion compound KTi 2 (PO 4 ) 3 The preparation of its carbon coating and its products and applications. Background technique

[0002] Energy consumption is an important feature of the development of modern society, and efficient energy storage systems are the core pillars of the renewable energy industry, consumer electronics industry, and transportation industry. Among many energy storage methods, lithium-ion batteries occupy a core position in today's energy storage industry due to their advantages such as light weight, high capacity and no memory effect. Due to the high energy density and good cycle performance of lithium-ion batteries, their use has expanded from portable electronic devices to electric vehicles and hybrid electric vehicles. However, the scarcity and uneven distribution of lithium resources, coupled with the increasing consumption makes...

Examples

Embodiment 1

[0030] polyanionic compound KTi 2 (PO 4 ) 3 The preparation steps are as follows:

[0031] 1) Weigh 0.5g of anatase titanium dioxide (TiO2) with an average particle size of 25nm 2 ), 0.5g potassium dihydrogen phosphate dihydrate (KH 2 PO 4 2H 2 O), measure volume 0.5mL85% phosphoric acid (H 3 PO 4 ), 0.5mL deionized water and thoroughly grind and mix well.

[0032] 2) Transfer the mixture obtained above to the liner of a polytetrafluoroethylene reactor, put it into a stainless steel shell, tighten it, and react in a constant temperature oven at 180-240°C for 24h.

[0033] 3) After cooling to room temperature, the product was collected by filtration, washed three times with ethanol and deionized water, and the obtained powder was vacuum-dried at 60°C for 12 hours to obtain KTi 2 (PO 4 ) 3 .

Embodiment 2

[0035] Carbon-encapsulated polyanionic compound KTi 2 (PO 4 ) 3 The preparation steps are as follows:

[0036] Get the dried KTi of Example 1 2 (PO 4 ) 3 Carry out high-energy planetary ball milling with a certain amount of sucrose (mass ratio 8:2) for 6-24 hours, and put the resultant into a tube furnace in an argon atmosphere for annealing at 300-600°C for 2-6 hours to obtain carbon coating KTi 2 (PO 4 ) 3 , KTi 2 (PO 4 ) 3 / C.

[0037] KTi prepared respectively by embodiment 1 and embodiment 2 2 (PO 4 ) 3 and KTi 2 (PO 4 ) 3 / C carries out electron microscope scanning to obtain such as figure 1 The scanning electron microscope picture shown, wherein (a) represents the KTi with nano-scale cubic structure 2 (PO 4 ) 3 The scanning electron microscope image; (b) shows the nano-scale cubic structure KT i2 (PO 4 ) 3 / C SEM image. Depend on figure 1 It can be seen that KTi 2 (PO 4 ) 3 The cubic structure is uniform in shape and has a small size, KT i2...

technical field

[0001] The invention belongs to the field of potassium ion battery materials, in particular to a polyanion compound KTi 2 (PO 4 ) 3 The preparation of its carbon coating and its products and applications. Background technique

[0002] Energy consumption is an important feature of the development of modern society, and efficient energy storage systems are the core pillars of the renewable energy industry, consumer electronics industry, and transportation industry. Among many energy storage methods, lithium-ion batteries occupy a core position in today's energy storage industry due to their advantages such as light weight, high capacity and no memory effect. Due to the high energy density and good cycle performance of lithium-ion batteries, their use has expanded from portable electronic devices to electric vehicles and hybrid electric vehicles. However, the scarcity and uneven distribution of lithium resources, coupled with the increasing consumption makes...

Examples

Embodiment 1

[0030] polyanionic compound KTi 2 (PO 4 ) 3 The preparation steps are as follows:

[0031] 1) Weigh 0.5g of anatase titanium dioxide (TiO2) with an average particle size of 25nm 2 ), 0.5g potassium dihydrogen phosphate dihydrate (KH 2 PO 4 2H 2 O), measure volume 0.5mL85% phosphoric acid (H 3 PO 4 ), 0.5mL deionized water and thoroughly grind and mix well.

[0032] 2) Transfer the mixture obtained above to the liner of a polytetrafluoroethylene reactor, put it into a stainless steel shell, tighten it, and react in a constant temperature oven at 180-240°C for 24h.

[0033] 3) After cooling to room temperature, the product was collected by filtration, washed three times with ethanol and deionized water, and the obtained powder was vacuum-dried at 60°C for 12 hours to obtain KTi 2 (PO 4 ) 3 .

Embodiment 2

[0035] Carbon-encapsulated polyanionic compound KTi 2 (PO 4 ) 3 The preparation steps are as follows:

[0036] Get the dried KTi of Example 1 2 (PO 4 ) 3 Carry out high-energy planetary ball milling with a certain amount of sucrose (mass ratio 8:2) for 6-24 hours, and put the resultant into a tube furnace in an argon atmosphere for annealing at 300-600°C for 2-6 hours to obtain carbon coating KTi 2 (PO 4 ) 3 , KTi 2 (PO 4 ) 3 / C.

[0037] KTi prepared respectively by embodiment 1 and embodiment 2 2 (PO 4 ) 3 and KTi 2 (PO 4 ) 3 / C carries out electron microscope scanning to obtain such as figure 1 The scanning electron microscope picture shown, wherein (a) represents the KTi with nano-scale cubic structure 2 (PO 4 ) 3 The scanning electron microscope image; (b) shows the nano-scale cubic structure KT i2 (PO 4 ) 3 / C SEM image. Depend on figure 1 It can be seen that KTi 2 (PO 4 ) 3 The cubic structure is uniform in shape and has a small size, KT i2...

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