CN104891570A - Liquid phase synthetic Zr<4+> doped bismuth fluoride lithium-ion battery positive electrode material and preparation method thereof - Google Patents

Abstract

The invention relates to a liquid phase synthetic Zr<4+> doped bismuth fluoride lithium-ion battery positive electrode material and a preparation method thereof. According to the method, reaction raw materials such as an ammonium fluoride solution and a bismuth salt solution are converted into tiny liquid droplets through the effect of a surfactant, and with the effect of a specific auxiliary agent and the centrifugal force field, the generated bismuth fluoride solid small particles are subjected to surface auxiliary agent covering and concurrently leave the reaction system, such that the possibility that the generated bismuth fluoride solid small particles continuously act with the ammonium fluoride to form a plurality of the double salts is substantially reduced; with the Zr<4+> doping, the overpotential of the material is reduced; and the bismuth fluoride material adopted as the lithium-ion battery positive electrode material has the specific capacity exceeding 200 mAh.g<-1>. According to the present invention, the method has characteristics of low equipment requirement and high product purity, the condition that a plurality of the double salts of the bismuth fluoride and other side reaction products are generated in the liquid phase reaction can be avoided, and the material has the excellent electrochemical property.

Description

A kind of liquid phase synthesis Zr 4+bismuth anode material for lithium-ion batteries and preparation method thereof is fluoridized in doping

Technical field

The present invention relates to a kind of heavy body and fluoridize bismuth complex lithium electricity positive electrode material manufacture method technical field.

Background technology

Lithium-ion secondary cell have volume, weight energy than high, voltage is high, self-discharge rate is low, memory-less effect, have extended cycle life, the high absolute advantage of power density, have dollar of/year share more than 30,000,000,000 in global portable power source market at present and increase gradually with the speed more than 10%.Particularly in recent years, along with petering out of fossil energy, the new forms of energy such as sun power, wind energy, biomass energy become the alternative of traditional energy gradually, and wherein wind energy, sun power have intermittence, use a large amount of energy-storage batteries for meeting the supply of electric power needs continued simultaneously; The urban air-quality problem that vehicle exhaust brings is day by day serious, and instant stage has been arrived in vigorously advocating and developing of power truck (EV) or hybrid electric vehicle (HEV); These demands provide lithium ion battery explosive growth point, also have higher requirement to the performance of lithium ion battery simultaneously.

The raising of the capacity of anode material for lithium-ion batteries is the primary goal that scientific and technical personnel study, and the research and development of heavy body positive electrode material can alleviate that current Li-ion batteries piles volume is large, heavy weight, price are high-leveled and difficult with the situation meeting high power consumption and high-power equipment needs.But since lithium ion battery commercialization in 1991, the actual specific capacity of positive electrode material is hovered all the time between 100-180mAh/g, positive electrode material specific storage is low has become the bottleneck promoting lithium ion battery specific energy.The positive electrode material that the lithium ion battery of current commercialization is the most practical is LiCoO ₂, the theoretical specific capacity of cobalt acid lithium is 274mAh/g, and actual specific capacity is between 130-140mAh/g, and cobalt is strategic materials, expensive and have larger toxicity.Therefore in recent years, the researchist of countries in the world is devoted to the research and development of Olivine-type Cathode Material in Li-ion Batteries always, up till now, the lithium ion cell positive filtered out nearly tens of kinds, but really have potential commercial applications prospect or occurred that positive electrode material is commercially very few really.As lithium manganate having spinel structure LiMn ₂o ₄, its cost is lower, and than being easier to preparation, safety performance is also relatively good, but capacity is lower, and theoretical capacity is 148mAh/g, and actual capacity is at 100-120mAh/g, and this material capacity circulation hold facility is not good, and under high temperature, capacity attenuation is very fast, Mn ³⁺john-Teller effect and dissolving in the electrolyte annoying researchist for a long time.The LiNiO of laminate structure ₂and LiMnO ₂although there is larger theoretical specific capacity, be respectively 275mAh/g and 285mAh/g, their preparations are very difficult, and poor heat stability, cyclicity is very poor, and capacity attenuation is very fast.And current progressively business-like iron lithium phosphate LiFePO ₄cost is low, Heat stability is good, environmental friendliness, but its theoretical capacity about only has 170mAh/g, and actual capacity is in about 140mAh/g [Chun SY, Bloking J T, Chiang Y M, Nature Materials, 2002,1:123-128.].What have market outlook at present only has lithium vanadate Li more than the positive electrode material of 200mAh/g specific storage _1+xv ₃o ₈, Li _1+xv ₃o ₈material can have and has even close to the capacity of 300mAh/g, but its electric discharge average voltage is lower and also in production process barium oxide often toxicity is larger.High lithium is than on positive electrode material in recent years, particularly the high lithium of manganese base manganese-nickel binary and manganese base manganese-nickel-cobalt ternary solid solution system compares positive electrode material, there is the cost more than the volume ratio of 200mAh/g, higher thermostability and relative moderate and receive the concern of people, but performance under this material high magnification is very undesirable, limit its application [Young-Sik Hong in power cell, Yong Joon Park, et al., Solid State Ionics, 2005,176:1035-1042].

In recent years, fluorochemical positive electrode material enters the visual field of investigator because its capacity is high, the prices of raw and semifnished materials are low.The principle of work of fluoride materials and conventional lithium ion battery positive electrode material is different, all there is lithium ion and can embed or the space of deintercalation in traditional lithium ion cell positive and negative pole, and the lithium ion in ionogen embeds between a positive electrode and a negative electrode back and forth and deintercalation and " rocking chair " battery proposed as Armand etc. that discharges.Fluorochemical is then a kind of transition material, namely in whole discharge process, although Me has nothing in common with each other, and MeF _nsimilar change [Badway F, Cosandey F, Pereira N, et al., Electrodes for Li Batteries, J.Electrochem.Soc., 2003,150 (10): A1318-A1327.] as follows can be there is:

nLi ⁺+MeF _n+ne ^-→nLiF+Me ⁰

Can discharge in this process far more than 200mAh.g ^-1specific storage, thus obtain investigation of materials personnel height attention.Wherein fluoridize bismuth owing to there being about 7170WhL ^-1volume and capacity ratio and have huge advantage.The conventional synthetic method of fluoridizing bismuth is at high temperature reacting with hydrogen fluoride gas and metal oxide/oxyhydroxide or fluorine gas and metal simple-substance, and processing condition harshness, equipment requirements is very high, and energy consumption is high, and therefore price is very expensive.Liquid phase reaction preparation fluoridizes bismuth then often because too high cannot the use as positive electrode material of by-products content also lacks economy because the many costs of generation waste liquid are high simultaneously.Fluoridizing bismuth also has a negative characteristic to be namely that its electronic conductivity is extremely low as lithium ion secondary battery anode material, therefore can cause very high polarizing voltage in charge and discharge process.Ion doping is a kind of microtexture of effective adjustment lattice, changes the means of lattice electron and ionic transport properties, likely improves the chemical property of material.But it is very complicated to the mechanism of action of parent that ion doping or even polyion work in coordination with doping, effect is often difficult to expect.

Therefore develop that a kind of technique is simple, constant product quality, there is excellent electrochemical performance liquid phase synthesis fluoridize bismuth preparation method and fluoridize the key that bismuth material applies as secondary cell.

Summary of the invention

The present invention is directed to existing background technology and propose a kind of liquid phase synthesis Zr ⁴⁺bismuth anode material for lithium-ion batteries and preparation method thereof is fluoridized in doping, reaction raw materials ammonium fluoride solution and bismuth salts solution are become small small droplets by the role transformation of tensio-active agent by the method, and fluoridizing bismuth solid granule surface coverage auxiliary agent by the effect of specific adjuvant and centrifuge field by what generate and leaving reaction system simultaneously, its possibility forming multiple double salt that continues to work with Neutral ammonium fluoride is significantly reduced; Meanwhile, Zr is passed through ⁴⁺doping reduces the overpotential of material; This is fluoridized bismuth material and has more than 200mAh.g as anode material for lithium-ion batteries use ^-1specific storage, the method equipment requirements is low, and product purity is high, can avoid generating in liquid phase reaction and fluoridizes the side reaction products such as the multiple double salt of bismuth and have excellent chemical property.

This Zr ⁴⁺doping liquid phase synthesis fluoridizes bismuth anode material for lithium-ion batteries and preparation method thereof, it is characterized by: Neutral ammonium fluoride is dissolved in Neutral ammonium fluoride quality 4-5 water doubly, adds the auxiliary agent Z2 of the normal hexane of the quality 40%-60% of water, the auxiliary agent Z1 of the quality 5-10% of water, the quality 5-10% of water in this solution; In this system, insert mechanical stirring rake, stir 15-30 minute with the speed of 1500-2000rpm, after this leave standstill this solution 10-20 minute and claim this solution to be solution I; Be dissolved in after the auxiliary agent Z3 of bismuth salt, the zirconates of bismuth salt amount of substance 1-5%, the nitric acid of bismuth salt quality 0.5-5% and bismuth salt quality 0.5-5% is mixed in above-mentioned substance total mass 4-5 water doubly, add the auxiliary agent Z2 of the normal hexane of the quality 40%-60% of water, the auxiliary agent Z4 of the quality 5-10% of water, the quality 5-10% of water in this solution; In this system, insert mechanical stirring rake, stir 15-30 minute with the speed of 1500-2000rpm, after this leave standstill this solution 10-20 minute and claim this solution to be solution II; Solution II is put into 600-1000rpm rotate low speed centrifuge, simultaneously by solution I with 60-200 drip/minute speed be added drop-wise in solution II until solution I all dropwises; Then the rotating speed improving whizzer is to 1500rpm and maintain 20 minutes, and after this whizzer rotates and stops, adding solution total mass 0.5-1.5% sodium-chlor leave standstill 3-5 hour after through filtering, washing, drying step obtain Zr ⁴⁺doping liquid phase synthesis fluoridizes bismuth.

Bismuth salt in preparation method as above is the one in five nitric hydrate bismuths, bismuth chloride; Zirconates is the one in five nitric hydrate zirconiums, two nitric hydrate oxygen zirconiums, Zirconium disulfate tetrahydrate; Auxiliary agent Z1 is the one in dodecyl dimethyl hydroxypropyl sultaine, dodecyl dimethyl azochlorosulfonate propyl lycine, myristamide propyl group hydroxypropyl sultaine; Auxiliary agent Z2 is the one in propyl carbinol, Pentyl alcohol, n-hexyl alcohol; Auxiliary agent Z3 is the one in perfluoro-heptanoic acid, 2,2-difluoro cyclopropyl carboxylic acids, perfluoroglutaric acid; Auxiliary agent Z4 is the one in laurylamino-propionic acid sodium, sodium cocoyl glutamate, sodium lauroyl glutamate; In solution II, in the amount of substance of bismuth salt and solution I, the ratio of Neutral ammonium fluoride amount of substance is 1: 3.

Fig. 1 is charging capacity, loading capacity and efficiency for charge-discharge figure, voltage range 1.8V-4.0V, the charging and discharging currents 0.1C of front 10 circulations of this material.

Compared with prior art, the invention has the advantages that: reaction raw materials ammonium fluoride solution and bismuth salts solution are become small small droplets by the role transformation of tensio-active agent by the method, and fluoridizing bismuth solid granule surface coverage auxiliary agent by the effect of specific adjuvant and centrifuge field by what generate and leaving reaction system simultaneously, its possibility forming multiple double salt that continues to work with Neutral ammonium fluoride is significantly reduced; Meanwhile, Zr is passed through ⁴⁺doping reduces the overpotential of material; This is fluoridized bismuth material and has more than 200mAh.g as anode material for lithium-ion batteries use ^-1specific storage, the method equipment requirements is low, and product purity is high, can avoid generating in liquid phase reaction and fluoridizes the side reaction products such as the multiple double salt of bismuth and have excellent chemical property.

Accompanying drawing explanation

The charging capacity of front 10 circulations of this material of Fig. 1, loading capacity and efficiency for charge-discharge figure, voltage range 1.8V-4.0V, charging and discharging currents 0.1C.

Embodiment

Below in conjunction with embodiment, the present invention is described in further detail.

Embodiment 1: be dissolved in by Neutral ammonium fluoride in the water of Neutral ammonium fluoride quality 4 times, adds the propyl carbinol of the normal hexane of the quality 42% of water, the dodecyl dimethyl hydroxypropyl sultaine of the quality 5.5% of water, the quality 5.6% of water in this solution; In this system, insert mechanical stirring rake, stir 17 minutes with the speed of 1600rpm, after this leave standstill this solution 10 minutes and claim this solution to be solution I; Be dissolved in after the mixing of the perfluoro-heptanoic acid of two nitric hydrate oxygen zirconiums of five nitric hydrate bismuths, five nitric hydrate bismuth amount of substances 1.5%, the nitric acid of five nitric hydrate bismuth quality 0.5% and five nitric hydrate bismuth quality 0.6% in the water of above-mentioned substance total mass 4 times after mixing, add the Pentyl alcohol of the normal hexane of the quality 40% of water, the laurylamino-propionic acid sodium of the quality 5% of water, the quality 5% of water in this solution; In this system, insert mechanical stirring rake, stir 15 minutes with the speed of 1500rpm, after this leave standstill this solution 10 minutes and claim this solution to be solution II; Solution II is put into the low speed centrifuge rotated with 600rpm, the solution I being five nitric hydrate bismuth amount of substance 3 times in solution II is added drop-wise in solution II until solution I all dropwises with the speed of 70 droplets/minute simultaneously containing Neutral ammonium fluoride amount of substance; Then the rotating speed improving whizzer is to 1500rpm and maintain 20 minutes, and after this whizzer rotates and stops, and adds that solution total mass 0.5% sodium-chlor to leave standstill after 3 hours through filtering, washing, drying step obtain Zr ⁴⁺doping liquid phase synthesis fluoridizes bismuth.

Embodiment 2: be dissolved in by Neutral ammonium fluoride in the water of Neutral ammonium fluoride quality 4.5 times, adds the Pentyl alcohol of the normal hexane of the quality 50% of water, the dodecyl dimethyl azochlorosulfonate propyl lycine of the quality 7% of water, the quality 7% of water in this solution; In this system, insert mechanical stirring rake, stir 20 minutes with the speed of 1800rpm, after this leave standstill this solution 15 minutes and claim this solution to be solution I; Be dissolved in after the mixing of the perfluoro-heptanoic acid of five nitric hydrate zirconiums of five nitric hydrate bismuths, five nitric hydrate bismuth amount of substances 1.5%, the nitric acid of five nitric hydrate bismuth quality 5% and five nitric hydrate bismuth quality 0.6% in the water of above-mentioned substance total mass 4 times after mixing, add the propyl carbinol of the normal hexane of the quality 40% of water, the sodium cocoyl glutamate of the quality 5% of water, the quality 5% of water in this solution; In this system, insert mechanical stirring rake, stir 20 minutes with the speed of 1800rpm, after this leave standstill this solution 16 minutes and claim this solution to be solution II; Solution II is put into the low speed centrifuge rotated with 800rpm, the solution I being five nitric hydrate bismuth amount of substance 3 times in solution II is added drop-wise in solution II until solution I all dropwises with the speed of 150 droplets/minute simultaneously containing Neutral ammonium fluoride amount of substance; Then the rotating speed improving whizzer is to 1500rpm and maintain 20 minutes, and after this whizzer rotates and stops, and adds that solution total mass 1.0% sodium-chlor to leave standstill after 4 hours through filtering, washing, drying step obtain Zr ⁴⁺doping liquid phase synthesis fluoridizes bismuth.

Embodiment 3: be dissolved in by Neutral ammonium fluoride in the water of Neutral ammonium fluoride quality 5 times, adds the n-hexyl alcohol of the normal hexane of the quality 58% of water, the myristamide propyl group hydroxypropyl sultaine of the quality 9% of water, the quality 9.5% of water in this solution; In this system, insert mechanical stirring rake, stir 30 minutes with the speed of 2000rpm, after this leave standstill this solution 20 minutes and claim this solution to be solution I; By 2 of the Zirconium disulfate tetrahydrate of bismuth chloride, bismuth chloride amount of substance 5%, the nitric acid of bismuth chloride quality 3.5% and bismuth chloride quality 5%, be dissolved in the water of above-mentioned substance total mass 5 times after the mixing of 2-difluoro cyclopropyl carboxylic acid, add the n-hexyl alcohol of the normal hexane of the quality 60% of water, the sodium lauroyl glutamate of the quality 9% of water, the quality 9% of water in this solution; In this system, insert mechanical stirring rake, stir 30 minutes with the speed of 2000rpm, after this leave standstill this solution 20 minutes and claim this solution to be solution II; Solution II is put into the low speed centrifuge rotated with 1000rpm, the solution I being bismuth chloride amount of substance 3 times in solution II is added drop-wise in solution II until solution I all dropwises with the speed of 200 droplets/minute simultaneously containing Neutral ammonium fluoride amount of substance; Then the rotating speed improving whizzer is to 1500rpm and maintain 20 minutes, and after this whizzer rotates and stops, and adds that solution total mass 1.5% sodium-chlor to leave standstill after 5 hours through filtering, washing, drying step obtain Zr ⁴⁺doping liquid phase synthesis fluoridizes bismuth.

Embodiment 4: be dissolved in by Neutral ammonium fluoride in the water of Neutral ammonium fluoride quality 4 times, adds the n-hexyl alcohol of the normal hexane of the quality 41% of water, the dodecyl dimethyl azochlorosulfonate propyl lycine of the quality 8% of water, the quality 7% of water in this solution; In this system, insert mechanical stirring rake, stir 30 minutes with the speed of 1850rpm, after this leave standstill this solution 20 minutes and claim this solution to be solution I; Be dissolved in the water of above-mentioned substance total mass 4.6 times after the perfluoroglutaric acid of the Zirconium disulfate tetrahydrate of bismuth chloride, bismuth chloride amount of substance 4%, the nitric acid of bismuth chloride quality 2% and bismuth chloride quality 3.8% is mixed, add the n-hexyl alcohol of the normal hexane of the quality 50% of water, the sodium lauroyl glutamate of the quality 7% of water, the quality 9% of water in this solution; In this system, insert mechanical stirring rake, stir 23 minutes with the speed of 1900rpm, after this leave standstill this solution 18 minutes and claim this solution to be solution II; Solution II is put into the low speed centrifuge rotated with 800rpm, the solution I being bismuth chloride amount of substance 3 times in solution II is added drop-wise in solution II until solution I all dropwises with the speed of 180 droplets/minute simultaneously containing Neutral ammonium fluoride amount of substance; Then the rotating speed improving whizzer is to 1500rpm and maintain 20 minutes, and after this whizzer rotates and stops, and adds that solution total mass 1.0% sodium-chlor to leave standstill after 4 hours through filtering, washing, drying step obtain Zr ⁴⁺doping liquid phase synthesis fluoridizes bismuth.

Embodiment 5: be dissolved in by Neutral ammonium fluoride in the water of Neutral ammonium fluoride quality 4.6 times, adds the Pentyl alcohol of the normal hexane of the quality 52% of water, the myristamide propyl group hydroxypropyl sultaine of the quality 8% of water, the quality 9.5% of water in this solution; In this system, insert mechanical stirring rake, stir 30 minutes with the speed of 1900rpm, after this leave standstill this solution 20 minutes and claim this solution to be solution I; Be dissolved in the water of above-mentioned substance total mass 4.6 times after the perfluoroglutaric acid of two nitric hydrate oxygen zirconiums of bismuth chloride, bismuth chloride amount of substance 4%, the nitric acid of bismuth chloride quality 3% and bismuth chloride quality 3.8% is mixed, add the n-hexyl alcohol of the normal hexane of the quality 50% of water, the sodium cocoyl glutamate of the quality 7% of water, the quality 7% of water in this solution; In this system, insert mechanical stirring rake, stir 23 minutes with the speed of 1700rpm, after this leave standstill this solution 18 minutes and claim this solution to be solution II; Solution II is put into the low speed centrifuge rotated with 900rpm, the solution I being bismuth chloride amount of substance 3 times in solution II is added drop-wise in solution II until solution I all dropwises with the speed of 160 droplets/minute simultaneously containing Neutral ammonium fluoride amount of substance; Then the rotating speed improving whizzer is to 1500rpm and maintain 20 minutes, and after this whizzer rotates and stops, and adds that solution total mass 1.2% sodium-chlor to leave standstill after 4.6 hours through filtering, washing, drying step obtain Zr ⁴⁺doping liquid phase synthesis fluoridizes bismuth.

Claims (2)

1. a liquid phase synthesis Zr ⁴⁺bismuth anode material for lithium-ion batteries and preparation method thereof is fluoridized in doping, it is characterized in that Neutral ammonium fluoride being dissolved in Neutral ammonium fluoride quality 4-5 water doubly, add the auxiliary agent Z2 of the normal hexane of the quality 40%-60% of water, the auxiliary agent Z1 of the quality 5-10% of water, the quality 5-10% of water in this solution; In this system, insert mechanical stirring rake, stir 15-30 minute with the speed of 1500-2000rpm, after this leave standstill this solution 10-20 minute and claim this solution to be solution I; Be dissolved in after the auxiliary agent Z3 of bismuth salt, the zirconates of bismuth salt amount of substance 1-5%, the nitric acid of bismuth salt quality 0.5-5% and bismuth salt quality 0.5-5% is mixed in above-mentioned substance total mass 4-5 water doubly, add the auxiliary agent Z2 of the normal hexane of the quality 40%-60% of water, the auxiliary agent Z4 of the quality 5-10% of water, the quality 5-10% of water in this solution; In this system, insert mechanical stirring rake, stir 15-30 minute with the speed of 1500-2000rpm, after this leave standstill this solution 10-20 minute and claim this solution to be solution II; Solution II is put into 600-1000rpm rotate low speed centrifuge, simultaneously by solution I with 60-200 drip/minute speed be added drop-wise in solution II until solution I all dropwises; Then the rotating speed improving whizzer is to 1500rpm and maintain 20 minutes, and after this whizzer rotates and stops, adding solution total mass 0.5-1.5% sodium-chlor leave standstill 3-5 hour after through filtering, washing, drying step obtain Zr ⁴⁺doping liquid phase synthesis fluoridizes bismuth;

Bismuth salt in preparation method as above is the one in five nitric hydrate bismuths, bismuth chloride; Zirconates is the one in five nitric hydrate zirconiums, two nitric hydrate oxygen zirconiums, Zirconium disulfate tetrahydrate; Auxiliary agent Z1 is the one in dodecyl dimethyl hydroxypropyl sultaine, dodecyl dimethyl azochlorosulfonate propyl lycine, myristamide propyl group hydroxypropyl sultaine; Auxiliary agent Z2 is the one in propyl carbinol, Pentyl alcohol, n-hexyl alcohol; Auxiliary agent Z3 is the one in perfluoro-heptanoic acid, 2,2-difluoro cyclopropyl carboxylic acids, perfluoroglutaric acid; Auxiliary agent Z4 is the one in laurylamino-propionic acid sodium, sodium cocoyl glutamate, sodium lauroyl glutamate; In solution II, in the amount of substance of bismuth salt and solution I, the ratio of Neutral ammonium fluoride amount of substance is 1: 3.

2. liquid phase synthesis Zr according to claim 1 ⁴⁺bismuth anode material for lithium-ion batteries and preparation method thereof is fluoridized in doping, it is characterized in that the bismuth of fluoridizing prepared has more than 200mAh.g ^-1specific storage.