阅读说明：本技术 一种用于锂电池纯硅阳极的锂-硅化合物多晶型及其用途 (Lithium-silicon compound polycrystalline type for pure silicon anode of lithium battery and application of lithium-silicon compound polycrystalline type ) 是由 陈世伟 于 2019-04-12 设计创作，主要内容包括：一种用于锂电池纯硅阳极的锂-硅化合物多晶型及其用于锂电池纯硅阳极的用途及制法,该纯硅阳极包含核种(102),核种(102)具有与Li-(4.1)Si-Cmcm、Li-(13)Si-(4)-Pbam、Li-(2)Si-C12ml、LiSi-I41/AZ其中的一种或多种相同的原子级结构。其中,Li-(4.1)Si-Cmcm原为高温稳定相,不被相信会存在于常温、存在于锂电池纯硅阳极,却被清楚证实,存在于揭露的材料内。拥有该核种的纯硅阳极,在充电(锂化反应)过后,整体结构会形成Li-(4.1)Si-Cmcm、Li-(13)Si-(4)-Pbam、Li-(2)Si-C12ml、LiSi-I41/AZ其中的一种或多种,并展现极优异的电容量,经过250圈充放电循环后,仍能保有2500mAh/g的电容量。能同时提升纯硅阳极实际使用时的电容量、并解决现有的纯硅阳极经反复充放电后体积膨胀而导致电极损坏进而使电池失效的问题。(A polymorphic form of a lithium-silicon compound for use in a pure silicon anode for a lithium battery, comprising a seed (102), the seed (102) having Li and its use and method of manufacture 4.1 Si_Cmcm、Li 13 Si 4 _Pbam、Li 2 One or more of Si _ C12ml and LiSi _ I41/AZ have the same atomic scale structure. Wherein Li 4.1 Si _ Cmcm was originally a high temperature stable phase not believed to exist at room temperature in pure silicon anodes for lithium batteries, but was clearly confirmed to exist within the disclosed materials. The pure silicon anode with the nuclear species can form Li in the whole structure after charging (lithiation reaction) 4.1 Si_Cmcm、Li 13 Si 4 _Pbam、Li 2 One or more of Si _ C12ml and LiSi _ I41/AZ, and the high-capacity lithium ion battery has extremely excellent capacity, and can still maintain the capacity of 2500mAh/g after 250 cycles of charge and discharge. Can simultaneously promote the pure silicon anodeThe capacitance when in use, and solves the problem that the prior pure silicon anode is damaged by volume expansion after repeated charge and discharge so as to cause the failure of the battery.)

A polymorphic form of a lithium-silicon compound for use in a pure silicon anode of a lithium battery, having an X-ray powder diffraction pattern substantially the same as that shown in figure 5 and having an X-ray absorption spectrum substantially the same as that shown in figure 6A.

Lithium for pure silicon anode of lithium battery-a silicon compound polymorph characterized in that it is selected from one or more of Li_4.1Si_Cmcm、Li1 ₃Si ₄_Pbam、Li ₂Si _ C12/m1 and LiSi _ I41AZ ordered lattice structures, wherein:

the Li_4.1The Si _ Cmcm ordered lattice structure is characterized by having an X-ray powder diffraction under K.alpha.X radiation using a Cu target comprising 2 θ peak positions at 15.75 + -0.1 degrees, 20.72 + -0.1 degrees, 24.11 + -0.1 degrees, 26.05 + -0.1 degrees, 27.15 + -0.1 degrees, 39.52 + -0.1 degrees, 41.36 + -0.1 degrees, and 43.16 + -0.1 degrees;

the Li1₃Si ₄A Pbam ordered lattice structure characterized by X-ray powder diffraction under X-ray radiation using a Cu target K α X radiation comprising 2 θ peak positions at 12.33 ± 0.1 degrees, 20.72 ± 0.1 degrees, and 22.6 ± 0.1 degrees;

the Li₂The Si _ C12/m1_ ordered lattice structure is characterized by having an X-ray powder diffraction under K.alpha.X radiation using a Cu target comprising 2 theta peak positions at 14.05 + -0.1 degrees and 23.61 + -0.1 degrees;

the LiSi- _ I41AZ ordered lattice structure is characterized by having an X-ray powder diffraction pattern comprising 2 theta peak positions at 18.77 + -0.1 degrees, 19.28 + -0.1 degrees under K.alpha.X-radiation using a Cu target.

The polymorphic form of the lithium-silicon compound of claim 2, having an apparent absorption peak at 1847 ± 2eV of the incident light energy in the X-ray absorption spectrum.

A pure silicon anode for a lithium battery comprising one or more seeds characterized in that the seeds comprise the lithium-silicon compound polymorph of claim 2 or 3.

The pure silicon anode for a lithium battery as claimed in claim 4, wherein the size of the seed is 1nm to 5,000,000 nm.

A method of preparing a pure silicon anode for a lithium battery according to claim 4, comprising:

plating a protective layer on the surface of pure silicon powder and leaving micro-parts to generate one or more exposed surfaces with surface area less than 50nm²；

Compacting the powder and placing the compacted powder in a groove on a copper substrate, and covering the groove with a screen to prevent the powder from scattering;

carrying out lithium charging and lithium removing reactions, wherein the electrolyte is EC/DEC + FEC;

controlling the voltage to produce a lithium flux per unit area of the exposed surface having a lithium ion concentration of greater than 4 atomic percent;

the charging rate is controlled to be between 0.5C and 30C.

The pure silicon anode for lithium battery as claimed in claim 4, which is composed of hollow, multi-layered, porous, nanowire, nanorod or nanoparticle shape with shell thickness, film thickness, mold wall thickness, and line width of 1-100 nm.