CN106711415A

CN106711415A - Porous silicon composite negative electrode material and preparation method thereof

Info

Publication number: CN106711415A
Application number: CN201611177897.0A
Authority: CN
Inventors: 陈溢镭; 何畅雷; 夏永高; 刘兆平
Original assignee: Ningbo Fuli Battery Material Technology Co Ltd
Current assignee: Ningbo Fuli Battery Material Technology Co Ltd
Priority date: 2016-12-19
Filing date: 2016-12-19
Publication date: 2017-05-24
Anticipated expiration: 2036-12-19
Also published as: CN106711415B

Abstract

The invention provides a porous silicon composite negative electrode material including a porous silicon substrate, a first conductive material layer composited on the surface of the porous silicon substrate, and a nano silicon-based material composited on the surface of the first conductive material layer. Firstly, a conductive material is coated for a first time, then the surface of the conductive material layer continues to be composited with the nano silicon-based material, and the porous silicon composite negative electrode material is obtained; the relatively high first charge/discharge efficiency of the porous silicon material is used, the conductive material coating the surface of the porous silicon material can increase the electrical conductivity of the composite material, can inhibit the porous silicon material from expanding outward to prevent rupture, and improves the cycle stability; after the surface is composited with the nano silicon-based material, better cycle performance is achieved, and the cycle performance of the porous silicon material composite material can be improved; and in addition, the preparation method has the advantages of simple operation, safety, high universality and low costs of production and is suitable for industrialized production.

Description

A kind of porous silicon composite cathode material and preparation method thereof

Technical field

The present invention relates to technical field of lithium ion battery electrode, it is related to a kind of porous silicon composite cathode material and its system Preparation Method, more particularly to a kind of porous silicon composite cathode material for lithium ion battery and preparation method thereof.

Background technology

Lithium ion battery has that operating voltage is high, specific energy is high, have extended cycle life, lightweight, self discharge is few, memoryless effect Should be with cost performance ratio, it has also become the field such as high power electric vehicle, artificial satellite, Aero-Space rechargeable type power supply Main selecting object.Especially in actual applications, lithium ion battery has become the ideal of all kinds of portable electric appts The energy, such as notebook computer, mobile phone etc..But current lithium ion battery cannot meet the electric automobile of fast development Requirement Deng novel electron equipment is, it is necessary to energy density higher, cycle life and lower cost.

Therefore, lithium ion battery and its associated materials turn into the study hotspot of numerous manufacturers and scientific research personnel.Except positive pole Material is that beyond lithium ion battery critical material, negative material equally decides the performance of lithium ion battery, and graphite type material is The main negative material of lithium ion electronics, its theoretical specific capacity is only 372mAh/g, limits the energy density of lithium ion battery.

And silica-base material extensively concerned at present, it is a kind of novel cathode material for lithium ion battery, with the theoretical embedding lithium of height Specific capacity 4200mAh/g, and rich reserves.But, there is violent contraction and expansion in charge and discharge process in silicium cathode, its Volume change causes silicon grain efflorescence more than 300%, and active material departs from binding agent；Simultaneously SEI films in cyclic process not Disconnected rupture and regeneration, constantly consume electrolyte, reduce cyclical stability.

Research finds that porous silicon can effectively improve the cycle performance of battery, Mingyuan Ge etc. and utilize AgNO₃And HF Electrochemical etching silicon nanowires, obtains porous silicon nanowires.(Porous Doped Silicon Nanowires for Lithium Ion Battery Anode with Long Cycle Life, Nano Lett, 2012,12,2318-2323). The porous silicon in this way preparing can reach more preferable cycle performance and first discharge specific capacity, but its preparation cost really Height, operation difficulty is big, increased production requirement and difficulty, therefore it is only limitted to small lot preparation at present, it is impossible to pushed away on a large scale Extensively.Jiang Zhiyu et al. is prepared for the porous silicon of different porosities using acid corrosion silicon alloy, and (a kind of Jiang Zhiyu, lithium ion battery is more Hole silicium cathode material and its production and use：China, 103165874A [P], 2013-06-19), although this porous silicon Can commercially produce, be easily destroyed with cycle efficieny first high, but its loose structure, cause it in charge and discharge process Active material departs from, and shortens cycle life.

Therefore, how to obtain a kind of preparation method simply, and there can be the porous silicium cathode material of preferable electrical property Material, is always the complex art problem of field of lithium ion battery, is also all multi-vendor and researcher's extensive concern in field Problem.

The content of the invention

In view of this, the technical problem to be solved in the present invention is to provide a kind of porous silicon composite cathode material and its preparation Method, particularly a kind of porous silicon composite cathode material for lithium ion battery and preparation method thereof, it is many that the present invention is provided Hole silicon composite cathode material, with discharging efficiency first and preferable cyclical stability higher, and the system that the present invention is provided Preparation Method is simple to operate, safety, highly versatile, suitable for large-scale production and application.

The invention provides a kind of porous silicon composite cathode material, including porous silicon matrix, it is compounded in the porous silicon-base First conductive material layer in body surface face, and it is compounded in the nano silica-base material of the first conductive material layer surface.

Preferably, also including being compounded in second outer layer of conductive material on the nano silica-base material surface.

Preferably, the porous silicon matrix is porous silicon grain；

The nano silica-base material include the mixture of silicon nanoparticle and nanometer conductive material, the oxygen-containing silicon grain of nanometer and One or more in the mixture and silicon nanoparticle of nanometer conductive material；

The nano silica-base material is (1~2) with the mass ratio of the porous silicon matrix：(3~12).

Preferably, the mixture of first conductive material including conductive carbon material, conductive carbon material and alloy material or Alloy material；

First conductive material is 1 with the mass ratio of the porous silicon matrix：(3~12)；

Second conductive material includes the mixture or alloy material of conductive carbon material, conductive carbon material and alloy material Material；Second conductive material is 1 with the mass ratio of the porous silicon matrix：(3~12)；

The alloy material includes metallic element alloy and/or metallic element and nonmetalloid alloy.

Preferably, the conductive carbon material includes Graphene, CNT, carbon nanocoils, carbon fiber, electrically conductive graphite, receives One or more in meter Shi Mo, cracking carbon and conductive black.

Present invention also offers a kind of preparation method of porous silicon composite cathode material, comprise the following steps：

(1) porous silicon matrix is coated using the first conductive material presoma, then processes 5 at 400~1600 DEG C ~10 hours, obtain the first presoma；

The first conductive material presoma includes conductive carbon material material precursor, conductive carbon material material precursor and alloy material The mixture or alloy material presoma of presoma；

It is described to include emulsification cladding, liquid phase coating, gas phase cladding or solid phase cladding；

(2) the first presoma is combined with nano silicon-based raw material, is then processed 5~10 hours at 400~1600 DEG C, Obtain porous silicon composite cathode material；

The nano silicon-based raw material includes silicon source, or silicon source and other raw materials mixture；Described other raw materials include receiving Rice conductive material and/or conductive carbon material material precursor；

Described being combined includes that emulsification is compound, liquid phase is compound, gaseous recombination or solid phase are compound.

Preferably, cladding treatment is carried out again to the porous silicon composite cathode material；

The cladding is processed as：Porous silicon composite cathode material is coated using the second conductive material presoma, so Processed 5~10 hours at 400~1500 DEG C afterwards；

The second conductive material presoma includes conductive carbon material material precursor, conductive carbon material material precursor and alloy material The mixture or alloy material presoma of presoma；

The mass ratio of the porous silicon composite cathode material and the second conductive presoma is (5~10)：1.

Preferably, the conductive carbon material material precursor includes sucrose, glucose, phenolic resin and melamino-formaldehyde, first One or more in alkane and ethene；

The alloy material presoma includes molysite, aluminium salt, pink salt, mantoquita, titanium salt, alundum (Al2O3), tin ash, two One or more in titanium oxide and cupric oxide；

The silicon source includes SiH₄、Si₂H₆、Si₃H₈、SiCl₄、SiHCl₃、Si₂Cl₆、SiH₂Cl₂And SiH₃One kind in Cl Or it is various.

Preferably, cladding is specially in the step (1)：

By porous silicon and dispersed with stirring or the dissolving in a solvent of the first conductive material presoma, then it is spray-dried, obtains Cladding product；

The mass ratio of the porous silicon and the first conductive presoma is (1~2)：(1~5)；The solvent be water, ethanol, One or more in formaldehyde and toluene；

Or be：

By porous silicon and first conductive material presoma 5~24h of mixing and ball milling, obtain coating product；The porous silicon with The mass ratio of the first conductive presoma is (1~2)：(1~5)；

Or be：

Porous silicon is passed through inert gas and the first conductive material presoma at 500~1500 DEG C, then natural cooling To room temperature, obtain coating product；The mass ratio of the porous silicon and the first conductive presoma is (1~2)：(1~5)；Indifferent gas Body includes nitrogen and/or argon gas；

Or be：

By porous silicon and first conductive presoma 5~24h of mixing and ball milling, then indifferent gas is passed through at 500~1500 DEG C 5~20h of body and reducibility gas, naturally cools to room temperature, obtains coating product；The porous silicon and the first conductive presoma Mass ratio is (1~2)：(1~5)；The inert gas includes nitrogen and/or argon gas；The reducibility gas include hydrogen and/ Or ammonia；

Or be：

Porous silicon and the first conductive presoma are scattered in the solvent containing emulsifying agent, stir 5 at 10~100 DEG C~ 20h, is then centrifuged for obtaining coating product；The mass ratio of the porous silicon and the first conductive presoma is (1~2)：(1~5)；Institute Stating emulsifying agent includes one or more in Triton X-100, Span series and twain series emulsifier.

Preferably, it is combined in the step (2) and is specially：

By the first presoma and nano silicon-based raw material dispersed with stirring in a solvent, then it is spray-dried, obtains combination product； First presoma is (1~2) with the mass ratio of nano silicon-based raw material：(1~5)；The solvent be water, ethanol, formaldehyde and One or more in toluene；

Or be：

By the first presoma and 5~24h of nano silicon-based raw material mixing and ball milling, combination product is obtained；First presoma It is (1~2) with the mass ratio of nano silicon-based raw material：(1~5)；

Or be：

First presoma is passed through inert gas and nano silicon-based raw material at 500~1500 DEG C, is then naturally cooled to Room temperature, obtains combination product；First presoma is (1~2) with the mass ratio of nano silicon-based raw material：(1~5)；It is described lazy Property gas include nitrogen and/or argon gas；

Or be：

By the first presoma with nano silicon-based stock dispersion in the solvent containing emulsifying agent, stir 5 at 10~100 DEG C ~20h, is then centrifuged for obtaining combination product；First presoma is (1~2) with the mass ratio of nano silicon-based raw material：(1~ 5)；The emulsifying agent includes one or more in Triton X-100, Span series and twain series emulsifier.

The invention provides a kind of porous silicon composite cathode material, including porous silicon matrix, it is compounded in the porous silicon-base First conductive material layer in body surface face, and it is compounded in the nano silica-base material of the first conductive material layer surface.With it is existing Technology is compared, and the present invention occurs violent contraction and expansion for silicium cathode in charge and discharge process, causes silicon grain efflorescence, living Property material depart from binding agent；Constantly rupture and the regeneration in cyclic process of SEI films, constantly consumes electrolyte simultaneously, reduces and follows Many defects such as ring stability.The present invention carries out first time cladding using conductive material first, then again in conductive material layer Composite Nano silica-base material is continued on surface, obtains porous silicon composite cathode material, not only make use of porous silica material to have in itself First charge-discharge efficiency higher, and be coated on the conductive material on porous silica material surface and can not only increase composite Electric conductivity, outwards expansion causes rupture can also to suppress porous silica material, improves cyclical stability；Surface composite Nano silicon again After sill, with more preferable cycle performance, the cycle performance of porous silica material composite can be improved；Additionally, of the invention Preparation method is simple to operate, safety, highly versatile, low production cost, be adapted to industrialized production.Test result indicate that, this hair Bright porous silicon composite cathode material have height ratio capacity (>1300mAh/g), first charge-discharge efficiency high (>And Gao Xun 85%) Ring performance (150 circulations, capability retention is more than 90%).

Brief description of the drawings

Fig. 1 is porous silicon-base composite negative pole material SEM figures prepared by the embodiment of the present invention 7；

Fig. 2 is the first charge-discharge cyclic curve of porous silicon-base composite negative pole material prepared by the embodiment of the present invention 7；

Fig. 3 is the cycle performance curve of porous silicon-base composite negative pole material prepared by the embodiment of the present invention 7；

Fig. 4 is the efficiency for charge-discharge curve of porous silicon-base composite negative pole material prepared by the embodiment of the present invention 7；

Fig. 5 is the cycle performance curve of porous silicon-base composite negative pole material prepared by the embodiment of the present invention 9；

Fig. 6 is the efficiency for charge-discharge curve of porous silicon-base composite negative pole material prepared by the embodiment of the present invention 9.

Specific embodiment

In order to further appreciate that the present invention, the preferred embodiments of the invention are described with reference to embodiment, but It is it should be appreciated that these descriptions are simply to further illustrate the features and advantages of the present invention rather than to patent requirements of the present invention Limitation.

The all raw materials of the present invention, originate to it and are not particularly limited, commercially buying or according to people in the art Known to member prepared by conventional method.

The all raw materials of the present invention, are not particularly limited to its purity, present invention preferably employs the pure or lithium ion battery of analysis The conventional purity in field.

The present invention is not particularly limited to the porous silicon matrix, with porous silica material well known to those skilled in the art or Porous silica material for preparing negative material, those skilled in the art can be according to practical situations, quality requirement And properties of product are selected and adjusted, porous silicon matrix of the present invention is preferably porous silicon grain；It is of the present invention many The particle mean size of hole silicon substrate is preferably 0.1~30 μm, more preferably more preferably 0.5~25 μm, 1~20 μm, most preferably 5 ~15 μm.The maximum particle size of porous silicon matrix of the present invention is preferably smaller than equal to 40 μm, more preferably less than or equal to 35 μm, optimal Choosing is less than or equal to 30 μm.The magnetisable material content of porous silicon matrix of the present invention is preferably smaller than equal to 50ppm, more preferably less than Equal to 45ppm, most preferably less than equal to 40ppm.The specific surface area of porous silicon matrix of the present invention is preferably 30~ 600cm²/ g, more preferably 100~500cm²/ g, most preferably 200~400cm²/g。

The present invention is not particularly limited to first conductive material, with conductive material well known to those skilled in the art or It is usually used in the conductive material of the negative pole of lithium ion battery, those skilled in the art can be according to practical situations, quality It is required that and properties of product selected and adjusted, the first conductive material of the present invention preferably includes conductive carbon material, or leads The mixture of the mixture of electrical carbon material and alloy material, more preferably conductive carbon material and alloy material.

The present invention is not particularly limited to first conductive carbon material, with conductive carbon material well known to those skilled in the art Expect or be usually used in the conductive carbon material of the negative pole of lithium ion battery, those skilled in the art can be according to practical application feelings Condition, quality requirement and properties of product are selected and adjusted, the first conductive carbon material of the present invention preferably include Graphene, One or more in CNT, carbon nanocoils, carbon fiber, electrically conductive graphite, nano-graphite, cracking carbon and conductive black, more Preferably Graphene, CNT, carbon nanocoils, carbon fiber, electrically conductive graphite, nano-graphite, cracking carbon or conductive black.This hair It is bright that the alloy material is not particularly limited, with alloy material well known to those skilled in the art or it is usually used in lithium ion battery Negative pole alloy material, those skilled in the art can be according to practical situations, quality requirement and properties of product Selected and adjusted, alloy material of the present invention is preferably included metallic element alloy and/or metallic element with nonmetallic unit Element alloy, more preferably metallic element alloy, or metallic element and nonmetalloid alloy.The present invention does not have to the metallic element There is especially limitation, with the metallic element of metallic element well known to those skilled in the art or the electrode for being usually used in lithium ion battery i.e. Can, those skilled in the art can be selected and be adjusted, this hair according to practical situations, quality requirement and properties of product The bright metallic element preferably include titanium, tin, aluminium, iron, copper, antimony, nickel, manganese, cobalt, germanium, zinc, bismuth and sow in two or more, more Preferably titanium, tin, aluminium, iron, copper, antimony, nickel, manganese, cobalt, germanium, zinc, bismuth and two or three in sowing.The present invention is to described nonmetallic Element is not particularly limited, and with nonmetalloid well known to those skilled in the art, those skilled in the art can basis Practical situations, quality requirement and properties of product are selected and adjusted, and nonmetalloid of the present invention is preferably included Silicon and/or nitrogen, more preferably silicon or nitrogen.

The present invention is not particularly limited to the consumption of the conductive carbon material and alloy material, ripe with those skilled in the art The conventional amount used known, those skilled in the art can be carried out according to practical situations, quality requirement and properties of product Selection and adjust, in the mixture of conductive carbon material of the present invention and alloy material, the conductive carbon material and the alloy The mass ratio of the mixture of material is preferably (1~20)：(20~1), more preferably (5~15)：(15~5), most preferably (7 ~12)：(12~7).

The present invention is not particularly limited to the consumption of first conductive material, with routine well known to those skilled in the art Consumption, those skilled in the art can be selected and be adjusted according to practical situations, quality requirement and properties of product Whole, the first conductive material of the present invention accounts for the content preferably 0.1wt%~50wt% of the porous silicon composite cathode material, More preferably 0.5wt%~40wt%, more preferably 1wt%~30wt%, most preferably 10wt%~20wt%.The present invention is right The thickness of first conductive material layer is not particularly limited, and those skilled in the art can be according to practical situations, quality It is required that and properties of product selected and adjusted, the thickness of the first conductive material layer of the present invention is preferably 1~500nm, More preferably 10~450nm, more preferably 50~400nm, more preferably 100~300nm.

The present invention is not particularly limited to the compound definition, is with composite definitions well known to those skilled in the art Can, the present invention is preferably one or more in cladding, half cladding, stacking, growth, embedded, doping and deposition, of the present invention The compound more preferably cladding or half being compounded in the first conductive material layer of the porous silicon matrix surface are coated, most preferably Cladding.The present invention is not particularly limited to the cladding, is defined with cladding well known to those skilled in the art, this area skill Art personnel can be selected and be adjusted according to practical situations, quality requirement and properties of product.

The present invention is not particularly limited to the nano silica-base material, with conductive material well known to those skilled in the art Nano silica-base material, those skilled in the art can be carried out according to practical situations, quality requirement and properties of product Selection and adjust, nano silica-base material of the present invention preferably includes the mixture of silicon nanoparticle and nanometer conductive material, receives One or more in the mixture of the oxygen-containing silicon grain of rice and nanometer conductive material, nano silicon film and silicon nanoparticle, more preferably It is mixture, the nanometer of the mixture, the oxygen-containing silicon grain of nanometer and nanometer conductive material of silicon nanoparticle and nanometer conductive material Silicon fiml or silicon nanoparticle.

The present invention is not particularly limited to the granularity of the silicon nanoparticle, with nano-silicon well known to those skilled in the art The granularity of particle, those skilled in the art can be selected according to practical situations, quality requirement and properties of product Select and adjust, the particle mean size of silicon nanoparticle of the present invention is preferably 1.0~900nm, more preferably 10~800nm, more Preferably 100~700nm, most preferably 300~500nm.The present invention is not particularly limited to the nano silicon film, with this area Nano silicon film known to technical staff, those skilled in the art can be according to practical situations, quality requirement and product Moral character can be selected and adjusted, and nano silicon film of the present invention is preferably continuous nano silicon film；Nano-silicon of the present invention The thickness of film is preferably 1.0~900nm, more preferably more preferably 10~800nm, 100~700nm, most preferably 300~ 500nm.The present invention is not particularly limited to the oxygen-containing silicon grain of the nanometer, with the oxygen-containing silicon of nanometer well known to those skilled in the art Particle, those skilled in the art can be selected and be adjusted according to practical situations, quality requirement and properties of product Whole, the oxygen-containing silicon grain molecular formula of nanometer of the present invention is preferably SiO_x, the wherein span of x is preferably 0.3≤x≤1.5, More preferably 0.5≤x≤1.2, most preferably 0.7≤x≤1.0.The present invention does not have to the granularity of the oxygen-containing silicon grain of the nanometer Especially limitation, with the granularity of the oxygen-containing silicon grain of nanometer well known to those skilled in the art, those skilled in the art can be with root Selected and adjusted according to practical situations, quality requirement and properties of product, particle mean size of the present invention is preferably 1.0~900nm, more preferably 10~800nm, more preferably 100~700nm, most preferably 300~500nm.

The present invention is not particularly limited to the consumption of the nano silica-base material, with routine well known to those skilled in the art Consumption, those skilled in the art can be selected and be adjusted according to practical situations, quality requirement and properties of product Whole, nano silica-base material of the present invention accounts for the mass ratio preferably (1~2) of the porous silicon matrix：(3~12), more preferably It is (1.2~1.8)：(5~10), more preferably (1.3~1.7)：(6~9), most preferably (1.4~1.6)：(7~8).This hair It is bright that both ratios are not particularly limited when being preferably silicon nanoparticle and nanometer conductive material to the nano silica-base material, With conventional amount used well known to those skilled in the art and ratio, those skilled in the art can according to practical situations, Quality requirement and properties of product are selected and adjusted, the mixture of silicon nanoparticle of the present invention and nanometer conductive material In, the content of the nanometer conductive material is preferably 0.1wt%~50wt%, more preferably 0.5wt%~40wt%, more preferably It is 1wt%~30wt%, most preferably 10wt%~20wt%.It is oxygen-containing that the present invention is preferably nanometer to the nano silica-base material When silicon grain and nanometer conductive material, both additional proportions are not particularly limited, with routine well known to those skilled in the art Consumption and ratio, those skilled in the art can be selected according to practical situations, quality requirement and properties of product Select and adjust, in the mixture of the oxygen-containing silicon grain of nanometer of the present invention and nanometer conductive material, the nanometer conductive material Content is preferably 0.1wt%~50wt%, more preferably more preferably 0.5wt%~40wt%, 1wt%~30wt%, optimal Elect 10wt%~20wt% as.

The present invention is not particularly limited to the compound definition, is with composite definitions well known to those skilled in the art Can, the present invention is preferably one or more in cladding, half cladding, stacking, growth, embedded, doping and deposition, of the present invention The compound more preferably embedded or doping in the nano silica-base material of the first conductive material layer surface is compounded in, most preferably Doping.The present invention is not particularly limited to the doping, is defined with doping well known to those skilled in the art, this area skill Art personnel can be selected and be adjusted according to practical situations, quality requirement and properties of product.

The present invention is further to improve the stability and electric conductivity of porous silicon composite cathode material, and the porous silicon is combined Negative material further preferably includes being compounded in second outer layer of conductive material on the nano silica-base material surface, i.e., described nano silicon-based Material surface is combined the second outer layer of conductive material again.

The present invention is not particularly limited to second conductive material, with conductive material well known to those skilled in the art or It is usually used in the conductive material of the negative pole of lithium ion battery, those skilled in the art can be according to practical situations, quality It is required that and properties of product selected and adjusted, the second conductive material of the present invention preferably includes conductive carbon material, or leads The mixture of the mixture of electrical carbon material and alloy material, more preferably conductive carbon material and alloy material.

The present invention is not particularly limited to second conductive carbon material, with conductive carbon material well known to those skilled in the art Expect or be usually used in the conductive carbon material of the negative pole of lithium ion battery, those skilled in the art can be according to practical application feelings Condition, quality requirement and properties of product are selected and adjusted, the second conductive carbon material of the present invention preferably include Graphene, One or more in CNT, carbon nanocoils, carbon fiber, electrically conductive graphite, nano-graphite, cracking carbon and conductive black, more Preferably Graphene, CNT, carbon nanocoils, carbon fiber, electrically conductive graphite, nano-graphite, cracking carbon or conductive black.This hair It is bright that the alloy material is not particularly limited, with alloy material well known to those skilled in the art or it is usually used in lithium ion battery Negative pole alloy material, those skilled in the art can be according to practical situations, quality requirement and properties of product Selected and adjusted, alloy material of the present invention is preferably included metallic element alloy and/or metallic element with nonmetallic unit Element alloy, more preferably metallic element alloy, or metallic element and nonmetalloid alloy.The present invention does not have to the metallic element There is especially limitation, with the metallic element of metallic element well known to those skilled in the art or the electrode for being usually used in lithium ion battery i.e. Can, those skilled in the art can be selected and be adjusted, this hair according to practical situations, quality requirement and properties of product The bright metallic element preferably include titanium, tin, aluminium, iron, copper, antimony, nickel, manganese, cobalt, germanium, zinc, bismuth and sow in two or more, more Preferably titanium, tin, aluminium, iron, copper, antimony, nickel, manganese, cobalt, germanium, zinc, bismuth and two or three in sowing.The present invention is to described nonmetallic Element is not particularly limited, and with nonmetalloid well known to those skilled in the art, those skilled in the art can basis Practical situations, quality requirement and properties of product are selected and adjusted, and nonmetalloid of the present invention is preferably included Silicon and/or nitrogen, more preferably silicon or nitrogen.

The present invention is not particularly limited to the consumption of second conductive material, with routine well known to those skilled in the art Consumption, those skilled in the art can be selected and be adjusted according to practical situations, quality requirement and properties of product Whole, the second conductive material of the present invention accounts for the content preferably 0.1wt%~50wt% of the porous silicon composite cathode material, More preferably 0.5wt%~40wt%, more preferably 1wt%~30wt%, most preferably 10wt%~20wt%.The present invention is right The thickness of second conductive material layer is not particularly limited, and those skilled in the art can be according to practical situations, quality It is required that and properties of product selected and adjusted, the thickness of the second conductive material layer of the present invention is preferably 10~ 900nm, more preferably 100~800nm, more preferably 200~700nm, most preferably 300~600nm.Additionally, the present invention is right The consumption of the conductive material, i.e. the first conductive material, the consumption of the second conductive material are not particularly limited, with art technology Conventional amount used known to personnel, those skilled in the art can be according to practical situations, quality requirement and product Can be selected and be adjusted, the first conductive material of the present invention is preferably 1 with the mass ratio of the porous silicon matrix：(3~ 12), more preferably 1：(5~10), most preferably 1：(7~8)；Second conductive material of the present invention and the porous silicon matrix Mass ratio be preferably 1：(3~12), more preferably 1：(5~10), most preferably 1：(7~8).

Above-mentioned steps of the present invention provide a kind of porous silicon composite cathode material, and the present invention is carried out using conductive material first Coat for the first time, then continue composite Nano silica-base material in conductive material layer surface again, obtain porous silicon composite cathode material, The first charge-discharge efficiency higher that porous silica material has in itself is not only make use of, and is coated on leading for porous silica material surface Electric material can not only increase the electric conductivity of composite, and outwards expansion causes rupture can also to suppress porous silica material, improves Cyclical stability；Surface after composite Nano silica-base material, with more preferable cycle performance, can improve porous silica material and answer again The cycle performance of condensation material；Further, it is further continued for being mixed with the conductive material on nano silica-base material surface, can not only Increase the electric conductivity of composite again, it is also possible to alleviate the volumetric expansion of nano silica-base material, further increase circulation steady It is qualitative.

The present invention is compound with previous porous silicon such as without especially indicating to optimum principles such as the selection of the raw material and ratios It is consistent in negative material, or selected accordingly and adjusted i.e. according to the ratio in porous silicon composite cathode material Can, this is no longer going to repeat them.

The present invention is coated using the first conductive material presoma to porous silicon matrix, then at 400~1600 DEG C Reason 5~10 hours, obtains the first presoma.

The present invention is not particularly limited to the concept of the presoma, and the material is prepared with well known to those skilled in the art Raw material, those skilled in the art can be selected according to practical condition, quality requirement and properties of product and Adjustment.

The present invention is not particularly limited to the first conductive material presoma, with well known to those skilled in the art first The preparing raw material of conductive material, those skilled in the art can be according to practical condition, quality requirement and product Can be selected and be adjusted, the first conductive material presoma of the present invention is preferably included conductive carbon material material precursor, conductive carbon The mixture or alloy material presoma of material precursor and alloy material presoma.

The present invention is not particularly limited to the conductive carbon material material precursor, is led with preparation well known to those skilled in the art The raw material of electrical carbon material, those skilled in the art can enter according to practical condition, quality requirement and properties of product Row selection and adjustment, conductive carbon material material precursor of the present invention preferably include sucrose, glucose, phenolic resin and melamine One or more in formaldehyde, methane and ethene, more preferably sucrose, glucose, phenolic resin and melamino-formaldehyde, methane Or ethene.Can also be direct conductive carbon material, such as Graphene, CNT, carbon nanocoils, carbon fiber, electrically conductive graphite, receive One or more in meter Shi Mo, cracking carbon and conductive black.

The present invention is not particularly limited to the alloy material presoma, with well known to those skilled in the art for preparing The source metal of composite negative pole material, those skilled in the art can be according to practical condition, quality requirement and product Performance is selected and adjusted, and source metal of the present invention preferably includes molysite, aluminium salt, pink salt, mantoquita, titanium salt, manganese salt, germanium One or more in salt, cobalt salt, zinc salt, magnesium salts, alundum (Al2O3), tin ash, titanium dioxide and cupric oxide, more preferably Molysite, aluminium salt, pink salt, mantoquita, titanium salt, manganese salt, germanium salt, cobalt salt, zinc salt, magnesium salts, alundum (Al2O3), tin ash, titanium dioxide Two or more in titanium and cupric oxide.

The present invention is not particularly limited to the cladding, is coated with method for coating well known to those skilled in the art, Those skilled in the art can be selected and be adjusted according to practical condition, quality requirement and properties of product, the present invention The cladding preferably includes liquid phase coating, gas phase cladding or solid phase cladding.

The present invention is not particularly limited to the temperature of the treatment, with the temperature of heat treatment well known to those skilled in the art , those skilled in the art can be selected and be adjusted according to practical condition, quality requirement and properties of product, this The temperature for inventing the treatment is preferably 400~1600 DEG C, most preferably more preferably 600~1400 DEG C, 800~1200 DEG C. The present invention is not particularly limited to the time of the treatment, with the time of heat treatment well known to those skilled in the art, this Art personnel can be selected and be adjusted according to practical condition, quality requirement and properties of product, institute of the present invention The time for stating treatment is preferably 5~10 hours, more preferably 6~9 hours, most preferably 7~8 hours.

The present invention is not particularly limited to the detailed process of the treatment, with heat treatment well known to those skilled in the art Process, those skilled in the art can be selected and be adjusted according to practical condition, quality requirement and properties of product Whole, treatment of the present invention is preferably high-temperature heat treatment.It is of the present invention cladding for gas phase coat when, the treatment can be considered as Carried out simultaneously with gas phase cladding process, i.e. the pyroprocess of gas phase cladding.Particularly, when the conductive material contains source metal When, the treatment is particularly preferred as, and under conditions of reducibility gas, is processed (high-temperature heat treatment).The present invention is to described Reducibility gas are not particularly limited, and with reducibility gas well known to those skilled in the art, those skilled in the art can Selected and adjusted with according to practical condition, quality requirement and properties of product, reducibility gas of the present invention are excellent Choosing includes ammonia and protective gas；The protective gas preferably includes nitrogen and/or inert gas, more preferably nitrogen or Inert gas.

The present invention is the integrality and operability of raising technique, and the step (1) is specifically as follows：

The mass ratio of the porous silicon and the first conductive presoma is preferably (1~2)：(1~5), more preferably (1~2)： (2~4), most preferably (1.3~1.7)：(2.5~3.5)；The solvent is preferably the one kind in water, ethanol, formaldehyde and toluene Or it is various；

The step (1) can also be specifically：

By porous silicon and the first conductive material presoma mixing and ball milling preferably 5~24h, more preferably 10~20h, most preferably It is 13~17h；Obtain coating product；The mass ratio of the porous silicon and the first conductive presoma is preferably (1~2)：(1~5), More preferably (1~2)：(2~4), most preferably (1.3~1.7)：(2.5~3.5)；

The step (1) can also be specifically：

By porous silicon preferably at 500~1500 DEG C, more preferably 700~1300 DEG C, most preferably 900~1100 DEG C；Under Inert gas and the first conductive material presoma are passed through, room temperature is then naturally cooled to, obtain coating product；The porous silicon with The mass ratio of the first conductive presoma is (1~2)：(1~5), more preferably (1~2)：(2~4), most preferably (1.3~ 1.7)：(2.5~3.5)；Inert gas preferably includes nitrogen and/or argon gas；

The step (1) can also be specifically：

By porous silicon and the first conductive presoma mixing and ball milling preferably 5~24h, more preferably 10~20h, most preferably 13 ~17h；Then preferably at 500~1500 DEG C, more preferably 700~1300 DEG C, most preferably 900~1100 DEG C；Under be passed through it is lazy Property gas and reducibility gas preferably 5~20h, more preferably 8~17h, most preferably 10~15h；Room temperature is naturally cooled to, is obtained To cladding product；The mass ratio of the porous silicon and the first conductive presoma is (1~2)：(1~5), more preferably (1~2)： (2~4), most preferably (1.3~1.7)：(2.5~3.5)；The inert gas preferably includes nitrogen and/or argon gas；It is described to go back Originality gas preferably includes hydrogen and/or ammonia；

The step (1) can also be specifically：

Porous silicon and the first conductive presoma are scattered in the solvent containing emulsifying agent, it is more excellent preferably at 10~100 DEG C Elect 30~80 DEG C, most preferably 50~60 DEG C as；Lower stirring 5~20h, most preferably more preferably 8~17h, 10~15h；So Centrifugation afterwards obtains coating product；The mass ratio of the porous silicon and the first conductive presoma is (1~2)：(1~5), more preferably (1~2)：(2~4), most preferably (1.3~1.7)：(2.5~3.5)；The emulsifying agent preferably includes polyethylene glycol octyl group benzene One or more in base ether, Span series and twain series emulsifier.

The present invention then the first presoma is combined with nano silicon-based raw material, then 400~1600 DEG C process 5~ 10 hours, obtain porous silicon composite cathode material.

The present invention is not particularly limited to the nano silicon-based raw material, with nano-silicon base well known to those skilled in the art Material, those skilled in the art can be selected and be adjusted according to practical condition, quality requirement and properties of product, Nano silicon-based raw material of the present invention preferably includes silicon source, or silicon source and other raw materials mixture；Described other raw materials are preferred Including nanometer conductive material and/or conductive carbon material material precursor.Before the present invention is to the nanometer conductive material or conductive carbon material Drive consistent in scope and the optimum principle of body and foregoing nanometer conductive material and conductive carbon material material precursor, herein no longer one One repeats；Silicon source of the present invention preferably includes SiH₄、Si₂H₆、Si₃H₈、SiCl₄、SiHCl₃、Si₂Cl₆、SiH₂Cl₂Or SiH₃Cl, or direct nano silica-base material, such as oxygen-containing silicon grain of silicon nanoparticle, nanometer, nano silicon film and nanometer One or more in silicon grain.It is described when the present invention is to mixture that the nano silicon-based raw material is silicon source and other raw materials Ratio shared by nano silicon material or the silicon source is not particularly limited, and those skilled in the art can be according to actual production feelings Condition, quality requirement and properties of product are selected and adjusted, and nano silicon material of the present invention or the silicon source account for described receiving The content of rice silica-base material is preferably 40~99.99wt%, most preferably preferably 50~90wt%, 60~80wt%.

The present invention is the integrality and operability of raising technique, and the step (2) is specifically as follows：

By the first presoma and nano silicon-based raw material dispersed with stirring in a solvent, then it is spray-dried, obtains combination product； First presoma is preferably (1~2) with the mass ratio of nano silicon-based raw material：(1~5), more preferably (1~2)：(2~ 4), most preferably (1.3~1.7)：(2.5~3.5)；；The solvent be preferably one kind in water, ethanol, formaldehyde and toluene or It is various；

The step (2) can also be specifically：

By the first presoma and 5~24h of nano silicon-based raw material mixing and ball milling, more preferably 10~20h, most preferably 13~ 17h；Obtain combination product；First presoma is preferably (1~2) with the mass ratio of nano silicon-based raw material：(1~5), it is more excellent Elect as (1~2)：(2~4), most preferably (1.3~1.7)：(2.5~3.5)；

The step (2) can also be specifically：

By the first presoma at 500~1500 DEG C, more preferably 700~1300 DEG C, most preferably 900~1100 DEG C；Under Inert gas and nano silicon-based raw material are passed through, room temperature is then naturally cooled to, combination product is obtained；First presoma with receive The mass ratio of rice silyl starting material is preferably (1~2)：(1~5), more preferably (1~2)：(2~4), most preferably (1.3~ 1.7)：(2.5~3.5)；The inert gas preferably includes nitrogen and/or argon gas；

The step (2) can also be specifically：

By the first presoma with nano silicon-based stock dispersion in the solvent containing emulsifying agent, preferably at 10~100 DEG C, more Preferably 30~80 DEG C, most preferably 50~60 DEG C；Lower stirring 5~20h, most preferably more preferably 8~17h, 10~15h； It is then centrifuged for obtaining combination product；First presoma is preferably (1~2) with the mass ratio of nano silicon-based raw material：(1~5), More preferably (1~2)：(2~4), most preferably (1.3~1.7)：(2.5~3.5)；The emulsifying agent preferably includes poly- second two One or more in alcohol octyl phenyl ether, Span series and twain series emulsifier.

The present invention is not particularly limited to described being combined, compound with complex method well known to those skilled in the art, Those skilled in the art can be selected and be adjusted according to practical condition, quality requirement and properties of product, the present invention It is described it is compound preferably include that emulsification is compound, liquid phase is compound, gaseous recombination or solid phase are compound, more preferably emulsify compound or gas phase multiple Close, be specifically as follows emulsification cladding.

The present invention is not particularly limited to the temperature of the treatment in the step (2), with well known to those skilled in the art The temperature of heat treatment, those skilled in the art can be carried out according to practical condition, quality requirement and properties of product Selection and adjustment, the temperature of the treatment in step (2) of the present invention are preferably 400~1600 DEG C, more preferably 600~1400 DEG C, most preferably 800~1200 DEG C.The present invention is not particularly limited to the time of the treatment in the step (2), with this area The time of heat treatment known to technical staff, those skilled in the art can according to practical condition, quality requirement with And properties of product are selected and adjusted, the time of the treatment in step (2) of the present invention is preferably 5~10 hours, more excellent Elect 6~9 hours, most preferably 7~8 hours as.

The present invention is not particularly limited to the detailed process of the treatment in the step (2), ripe with those skilled in the art The process of the heat treatment known, those skilled in the art can be according to practical condition, quality requirement and properties of product Selected and adjusted, treatment is preferably high-temperature heat treatment in step (2) of the present invention.

The present invention is not particularly limited to the silicon source, with silicon source well known to those skilled in the art, this area skill Art personnel can be selected and be adjusted according to practical condition, quality requirement and properties of product, silicon source of the present invention Preferably include SiH₄、Si₂H₆、Si₃H₈、SiCl₄、SiHCl₃、Si₂Cl₆、SiH₂Cl₂And SiH₃One or more in Cl, more preferably It is SiH₄、Si₂H₆、Si₃H₈、SiCl₄、SiHCl₃、Si₂Cl₆、SiH₂Cl₂Or SiH₃Cl。

Further, to improve compound performance, the emulsification is compound to be most preferably emulsification cladding to the present invention.Institute of the present invention Stating step (2) can also be specifically, and the first presoma and nano silicon-based raw material are carried out into emulsification is combined and 400 under protective atmosphere ~1600 DEG C are processed 5~10 hours, obtain porous silicon composite cathode material；Or be by the first presoma and nanometer silicon source, receive Rice conductive material and conductive carbon material material precursor emulsify after being combined and being sintered under protective atmosphere (protective gas), Obtain porous silicon composite cathode material.

The compound emulsifying agent of emulsification of the present invention can also preferably include anionic emulsifier, cationic emulsification Agent or nonionic emulsifier, more specifically can be odium stearate salt, lauryl sodium sulfate salt, calcium dodecyl benzene sulfonate Salt, N- domiphens have polyethenoxy ether class or polyoxypropylene ethers；It is of the present invention to emulsify the milkiness being compounded to form Liquid type preferably include oil-in-water type, water-in-oil type, multiple emulsion, non-aqueous emulsion, liquid-crystal emulsion, color development emulsion, One or more in gel emulsion and phosphatide emulsion, more preferably oil-in-water type, water-in-oil type, multiple emulsion, non- Aqueous emulsion, liquid-crystal emulsion, color development emulsion, gel emulsion or phosphatide emulsion.

Particularly, the present invention is the cycle performance and stability of the porous silicon composite cathode material of raising, further preferably to institute State porous silicon composite cathode material carries out cladding treatment again, i.e., the porous silicon composite cathode material for being obtained to above-mentioned steps is again Cladding treatment is carried out, final porous silicon composite cathode material product is obtained.

The present invention is not particularly limited to the specific steps of the cladding treatment, with cladding well known to those skilled in the art Method is coated, and those skilled in the art can be selected according to practical condition, quality requirement and properties of product And adjustment, cladding of the present invention is processed and preferably includes emulsification cladding, liquid phase coating, gas phase cladding or solid phase cladding, specific to walk It is rapid to be more preferably：

Porous silicon composite cathode material is coated using the second conductive material presoma, then at 400~1500 DEG C Treatment 5~10 hours.

As without especially indicating, the present invention is to the detailed process of above-mentioned steps, selection, parameter and preferred scope and foregoing first Detailed process that conductive material presoma is coated to porous silicon matrix, selection, parameter are consistent with preferred scope, herein not Repeat one by one again.The present invention is conductive to the selection of above-mentioned second conductive material presoma, parameter and preferred scope and foregoing first The selection of material precursor, parameter are consistent with preferred scope, and this is no longer going to repeat them.Porous silicon Compound Negative of the present invention The mass ratio of pole material and the second conductive presoma is preferably (5~10)：1, more preferably (6~9)：1, most preferably (7~ 8)：1.

After the present invention is finally post-processed the semi-finished product that preferred above-mentioned steps are obtained, porous silicon composite cathode material is obtained Material.

The present invention is not particularly limited to the mode and step of the post processing, with routine well known to those skilled in the art Post processing mode and step, those skilled in the art can be according to practical condition, product situation and performance requirements Be adjusted, post processing of the present invention preferably include to grind, dry, sieving and except magnetic in one or more, more preferably Grinding, dry, sieving and except magnetic in it is various, most preferably grind, sieving and except magnetic.The present invention to above-mentioned grinding, sieving and Except the actual conditions of the postprocessing working procedures such as magnetic is not particularly limited, with above-mentioned postprocessing working procedures well known to those skilled in the art Condition, those skilled in the art can be adjusted according to practical condition, product situation and performance requirement.

Above-mentioned steps of the present invention are prepared for a kind of porous silicon composite cathode material, and the present invention is carried out using conductive material first Coat for the first time, then continue composite Nano silica-base material in conductive material layer surface again, obtain porous silicon composite cathode material, The first charge-discharge efficiency higher that porous silica material has in itself is not only make use of, and is coated on leading for porous silica material surface Electric material can not only increase the electric conductivity of composite, and outwards expansion causes rupture can also to suppress porous silica material, improves Cyclical stability；Surface after composite Nano silica-base material, with more preferable cycle performance, can improve porous silica material and answer again The cycle performance of condensation material；Further, it is further continued for being mixed with the conductive material on nano silica-base material surface, can not only Increase the electric conductivity of composite again, it is also possible to alleviate the volumetric expansion of nano silica-base material, further increase circulation steady It is qualitative.Particularly, the present invention is the performance of the porous silicon composite cathode material of raising, especially using emulsification composite algorithm to nano silicon-based Material is doped cladding.Additionally, preparation method of the invention is simple to operate, safety, highly versatile, low production cost, be adapted to Industrialized production.Test result indicate that, porous silicon composite cathode material of the invention have height ratio capacity (>1300mAh/g), it is high First charge-discharge efficiency (>85%) with high circulation performance (150 circulations, capability retention is more than 90%).

For a further understanding of the present invention, with reference to a kind of porous silicon composite cathode material that embodiment is provided the present invention Material and preparation method thereof is illustrated, but it is to be understood that these embodiments are entered under premised on technical solution of the present invention Row is implemented, and gives detailed implementation method and specific operating process, simply to further illustrate feature of the invention and excellent Point, rather than limiting to the claimed invention, protection scope of the present invention is also not necessarily limited to following embodiments.

Embodiment 1

Porous silicon is scattered in the solvent dissolved with grape grape, wherein porous silicon and the mass ratio of glucose is 1：1, it is porous Silicon specific surface area is 40cm²/ g, particle mean size is 13 μm.After being uniformly dispersed, it is spray-dried, EAT is 200 DEG C, is gone out Air temperature is 100 DEG C, and dispersion impeller rotating speed is 2000r/min, and then in nitrogen atmosphere, 800 DEG C of carbonization 5h are cooled to room afterwards Temperature, obtains the porous silica material of cladding cracking carbon, i.e. the first presoma.

The porous silica material that cracking carbon will be coated with is positioned in rotary furnace, in the case where high pure nitrogen flow is 5.0L/min, 500 DEG C are warming up to, high pure nitrogen is then changed into high-purity hydrogen and SiH₄Gaseous mixture, flow keeps constant, when being passed through silane Gas and first forerunner's body mass ratio are 1：Gas is changed to high pure nitrogen after 1, room temperature is naturally cooled to, porous silicon/lead is obtained Electric material clad/nano silica-base material composite.

Embodiment 2 and 3

It is identical in experimental procedure and embodiment 1 in embodiment 2 and 3, only change porous silicon and glucose mass ratio and The mass ratio of the first presoma and silane.The mass ratio of porous silicon and glucose is 2 in embodiment 2：1, the first presoma and silicon The mass ratio of alkane is 2：1；The mass ratio of porous silicon and glucose is 2 in embodiment 3：5, the mass ratio of the first presoma and silane It is 2：5.

Embodiment 4,5 and 6

Experiment in embodiment 4,5,6 is identical with embodiment 1,2,3 respectively, and silane is only changed to the mixing of silane and methane The mass ratio of gas, wherein silane and methane is 1：1, the gross mass of the mixed gas of silane and methane point in embodiment 4,5,6 The quality of silane is equal in other and embodiment 1,2,3.

Embodiment 7

Porous silicon is scattered in the ethanol dissolved with phenolic resin, wherein porous silicon and the mass ratio of phenolic resin is 2：1, The specific surface area of porous silicon is 150cm²/ g, particle mean size is 15 μm, is spray-dried after being well mixed, and EAT is 200 DEG C, Leaving air temp is 100 DEG C, and dispersion impeller rotating speed is 2000r/min, and then in nitrogen atmosphere, 800 DEG C of carbonization 5h are cooled to afterwards Room temperature, obtains the porous silica material of cladding cracking carbon, i.e. the first presoma.

First presoma is scattered in containing in nano-silicon, melamine, the alcohol of Triton X-100, rotating speed Be 500rmp, wherein porous silicon and nano-silicon, melamine mass ratio be 2：0.5：0.5, the average grain diameter of nano-silicon is 80nm, afterwards pours into the paraffin oil containing sorbester p17 dispersion liquid, and 1h is stirred vigorously at 60 DEG C, and rotating speed is 500rmp, it Afterwards at 100 DEG C continue stir 10h, the solid deionized water and ethanol wash that will be filtrated to get, then in nitrogen atmosphere, 800 DEG C of heating 5h, naturally cool to room temperature afterwards, obtain porous silicon/conductive material clad/nano silica-base material composite wood Material, i.e. semi-finished product.

After this semi-finished product composite is sieved, it is fitted into planetary ball mill after mixing with cupric oxide, loads the zirconium of 1mm Pearl, then passes to argon gas protective gas, carries out ball milling, and wherein drum's speed of rotation is the mass ratio of 400r/min, abrading-ball and powder It is 50:1, semi-finished product are 5 with the mass ratio of cupric oxide：1, after ball milling 10h, ball milling mixing powder is obtained, powder is put into tubular type In stove, 300 DEG C are heated in nitrogen atmosphere, then pass to the mixed gas of ammonia and nitrogen, constant temperature 3h switches to gas Then high pure nitrogen naturally cools to room temperature, this composite is crossed and screens out magnetic, obtains final porous silicon-base composite negative pole material Material product.

Referring to Fig. 1, Fig. 1 is the SEM of porous silicon composite cathode material prepared by the embodiment of the present invention 7 (SEM) picture.It may be seen that porous silicon composite cathode material is in spherical particle, median particle diameter is 15 μm, particle surface bag Coating is fine and close.

Referring to Fig. 2, Fig. 2 is the first charge-discharge curve of porous silicon composite cathode material prepared by the embodiment of the present invention 7.By Figure is visible, and porous silicon composite cathode material first discharge specific capacity prepared by embodiment 7 is higher.

Referring to Fig. 3, Fig. 3 is the cycle performance curve of porous silicon composite cathode material prepared by the embodiment of the present invention 7,150 After secondary circulation, capability retention is 92.3%, it is seen that it has preferable cycle performance.

Referring to Fig. 4, Fig. 4 is the change of the efficiency for charge-discharge of porous silicon composite cathode material prepared by the embodiment of the present invention 7 Curve.As seen from the figure, its first efficiency be 88.5%, and 5 times circulate after be rapidly reached 99.4%, in cyclic process In, efficiency keeps stabilization.

Embodiment 8

Embodiment 8 is identical with the experiment in embodiment 7, only will be last as follows with being changed to the step of aoxidizing copper clad semi-finished product Step：

Semi-finished product and glucose are dispersed in water, wherein the mass ratio of semi-finished product and glucose is 5：1；After well mixed Spray drying, EAT is 200 DEG C, and leaving air temp is 100 DEG C, and dispersion impeller rotating speed is 2000r/min, then in nitrogen atmosphere In, 800 DEG C of carbonization 5h are cooled to room temperature afterwards, obtain final porous silicon-base composite negative pole material product.

Embodiment 9 and 10

It is identical in experimental procedure and embodiment 7 in embodiment 9 and 10, only change the mass ratio of semi-finished product and cupric oxide. The mass ratio of semi-finished product and cupric oxide is 7 in embodiment 9：1；The mass ratio of semi-finished product and cupric oxide is 10 in embodiment 10：1.

Referring to Fig. 5, Fig. 5 is the cycle performance curve of porous silicon-base composite negative pole material prepared by the embodiment of the present invention 9.By Fig. 5 understands that after 150 times circulate, capability retention is 92.4%, and its cycle performance is higher.

Referring to Fig. 6, Fig. 6 is the efficiency for charge-discharge curve of porous silicon-base composite negative pole material prepared by the embodiment of the present invention 9. It will be appreciated from fig. 6 that its first cycle efficieny be 87.3%, and 6 times circulate after be rapidly reached 99.4%, in cyclic process In, efficiency keeps stabilization.

Embodiment 11 and 12

It is identical in experimental procedure and embodiment 8 in embodiment 11,12, only the mass ratio of semi-finished product and glucose is distinguished It is changed into 7：1 and 10：1.

The Electrochemical results of the porous silicon composite cathode material prepared by embodiment 1~12 are as shown in table 1

The electro-chemical test of the porous silicon composite cathode material prepared by the embodiment 1~12 of table 1

A kind of porous silicon composite cathode material for providing the present invention above and preparation method thereof is described in detail, Specific case used herein is set forth to principle of the invention and implementation method, and the explanation of above example is use Understand the method for the present invention and its core concept, including best mode in help, and also cause any technology people of this area Member can put into practice the present invention, including manufacture and use any device or system, and the method for implementing any combination.Should refer to Go out, for those skilled in the art, under the premise without departing from the principles of the invention, can also be to the present invention Some improvement and modification are carried out, these are improved and modification is also fallen into the protection domain of the claims in the present invention.Patent of the present invention The scope of protection is defined by the claims, and may include those skilled in the art it is conceivable that other embodiment.If These other embodiments have the structural element for being not different from claim character express, or if they include and right It is required that equivalent structural elements of the character express without essence difference, then these other embodiments should also be included in claim In the range of.

Claims

1. a kind of porous silicon composite cathode material, it is characterised in that including porous silicon matrix, be compounded in the porous silicon-base body surface First conductive material layer in face, and it is compounded in the nano silica-base material of the first conductive material layer surface.

2. porous silicon composite cathode material according to claim 1, it is characterised in that also including being compounded in the nano-silicon Second outer layer of conductive material on sill surface.

3. porous silicon composite cathode material according to claim 2, it is characterised in that the porous silicon matrix is porous silicon Particle；

The nano silica-base material includes mixture, the oxygen-containing silicon grain of nanometer and the nanometer of silicon nanoparticle and nanometer conductive material One or more in the mixture and silicon nanoparticle of conductive material；

4. porous silicon composite cathode material according to claim 2, it is characterised in that first conductive material includes leading The mixture or alloy material of electrical carbon material, conductive carbon material and alloy material；

Second conductive material includes the mixture or alloy material of conductive carbon material, conductive carbon material and alloy material；Institute It is 1 that the second conductive material is stated with the mass ratio of the porous silicon matrix：(3~12)；

5. porous silicon composite cathode material according to claim 4, it is characterised in that the conductive carbon material includes graphite One or more in alkene, CNT, carbon nanocoils, carbon fiber, electrically conductive graphite, nano-graphite, cracking carbon and conductive black.

6. a kind of preparation method of porous silicon composite cathode material, it is characterised in that comprise the following steps：

(1) porous silicon matrix is coated using the first conductive material presoma, then processes 5~10 at 400~1600 DEG C Hour, obtain the first presoma；

The first conductive material presoma includes conductive carbon material material precursor, conductive carbon material material precursor and alloy material forerunner The mixture or alloy material presoma of body；

(2) the first presoma is combined with nano silicon-based raw material, is then processed 5~10 hours at 400~1600 DEG C, obtained Porous silicon composite cathode material；

The nano silicon-based raw material includes silicon source, or silicon source and other raw materials mixture；Described other raw materials are led including nanometer Electric material and/or conductive carbon material material precursor；

7. preparation method according to claim 6, it is characterised in that carried out again to the porous silicon composite cathode material Cladding treatment；

The cladding is processed as：Porous silicon composite cathode material is coated using the second conductive material presoma, Ran Hou 400~1500 DEG C are processed 5~10 hours；

The second conductive material presoma includes conductive carbon material material precursor, conductive carbon material material precursor and alloy material forerunner The mixture or alloy material presoma of body；

8. the preparation method according to claim 6 or 7, it is characterised in that the conductive carbon material material precursor include sucrose, One or more in glucose, phenolic resin and melamino-formaldehyde, methane and ethene；

The alloy material presoma includes molysite, aluminium salt, pink salt, mantoquita, titanium salt, alundum (Al2O3), tin ash, titanium dioxide One or more in titanium and cupric oxide；

The silicon source includes SiH₄、Si₂H₆、Si₃H₈、SiCl₄、SiHCl₃、Si₂Cl₆、SiH₂Cl₂And SiH₃One kind or many in Cl Kind.

9. preparation method according to claim 6, it is characterised in that cladding is specially in the step (1)：

By porous silicon and dispersed with stirring or the dissolving in a solvent of the first conductive material presoma, then it is spray-dried, is coated Product；

The mass ratio of the porous silicon and the first conductive presoma is (1~2)：(1~5)；The solvent is water, ethanol, formaldehyde With one or more in toluene；

Or be：

By porous silicon and first conductive material presoma 5~24h of mixing and ball milling, obtain coating product；The porous silicon and first The mass ratio of conductive presoma is (1~2)：(1~5)；

Or be：

Porous silicon is passed through inert gas and the first conductive material presoma at 500~1500 DEG C, room is then naturally cooled to Temperature, obtains coating product；The mass ratio of the porous silicon and the first conductive presoma is (1~2)：(1~5)；Inert gas bag Include nitrogen and/or argon gas；

Or be：

By porous silicon and first conductive material presoma 5~24h of mixing and ball milling, then indifferent gas is passed through at 500~1500 DEG C 5~20h of body and reducibility gas, naturally cools to room temperature, obtains coating product；The porous silicon and the first conductive presoma Mass ratio is (1~2)：(1~5)；The inert gas includes nitrogen and/or argon gas；The reducibility gas include hydrogen and/ Or ammonia；

Or be：

Porous silicon and the first conductive material presoma are scattered in the solvent containing emulsifying agent, at 10~100 DEG C stir 5~ 20h, is then centrifuged for obtaining coating product；The mass ratio of the porous silicon and the first conductive presoma is (1~2)：(1~5)；Institute Stating emulsifying agent includes one or more in Triton X-100, Span series and twain series emulsifier.

10. preparation method according to claim 5, it is characterised in that be combined in the step (2) and be specially：

By the first presoma and nano silicon-based raw material dispersed with stirring in a solvent, then it is spray-dried, obtains combination product；It is described First presoma is (1~2) with the mass ratio of nano silicon-based raw material：(1~5)；The solvent is water, ethanol, formaldehyde and toluene In one or more；

Or be：

By the first presoma and 5~24h of nano silicon-based raw material mixing and ball milling, combination product is obtained；First presoma with receive The mass ratio of rice silyl starting material is (1~2)：(1~5)；

Or be：

First presoma is passed through inert gas and nano silicon-based raw material at 500~1500 DEG C, room temperature is then naturally cooled to, Obtain combination product；First presoma is (1~2) with the mass ratio of nano silicon-based raw material：(1~5)；The inert gas Including nitrogen and/or argon gas；

Or be：

By the first presoma with nano silicon-based stock dispersion in the solvent containing emulsifying agent, at 10~100 DEG C stir 5~ 20h, is then centrifuged for obtaining combination product；First presoma is (1~2) with the mass ratio of nano silicon-based raw material：(1~5)； The emulsifying agent includes one or more in Triton X-100, Span series and twain series emulsifier.