WO2017214882A1 - Porous silicon particles and a method for producing silicon particles - Google Patents

Porous silicon particles and a method for producing silicon particles Download PDF

Info

Publication number
WO2017214882A1
WO2017214882A1 PCT/CN2016/085848 CN2016085848W WO2017214882A1 WO 2017214882 A1 WO2017214882 A1 WO 2017214882A1 CN 2016085848 W CN2016085848 W CN 2016085848W WO 2017214882 A1 WO2017214882 A1 WO 2017214882A1
Authority
WO
WIPO (PCT)
Prior art keywords
anode
battery
cathode
voltage
lithium
Prior art date
Application number
PCT/CN2016/085848
Other languages
English (en)
French (fr)
Inventor
Jun Yang
Rongrong MIAO
Xiaolin Liu
Yuqian DOU
Jingjun Zhang
Rongrong JIANG
Lei Wang
Xiaogang HAO
Qiang Lu
Original Assignee
Robert Bosch Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch Gmbh filed Critical Robert Bosch Gmbh
Priority to CN201680035058.7A priority Critical patent/CN107848809B/zh
Priority to PCT/CN2016/085848 priority patent/WO2017214882A1/en
Publication of WO2017214882A1 publication Critical patent/WO2017214882A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/02—Silicon
    • C01B33/021—Preparation
    • C01B33/023—Preparation by reduction of silica or free silica-containing material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/049—Processes for forming or storing electrodes in the battery container
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/10—Particle morphology extending in one dimension, e.g. needle-like
    • C01P2004/17—Nanostrips, nanoribbons or nanobelts, i.e. solid nanofibres with two significantly differing dimensions between 1-100 nanometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/12—Surface area
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/14—Pore volume
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M2010/4292—Aspects relating to capacity ratio of electrodes/electrolyte or anode/cathode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H01M2300/0028—Organic electrolyte characterised by the solvent
    • H01M2300/0034—Fluorinated solvents
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to porous silicon particles, a method for producing silicon particles, a silicon-carbon composite, an electrode material and a battery comprising said composite, a method for producing said battery, and the use of the silicon-carbon composite as an electrode active material.
  • silicon with nano-scaled size could buffer the large (de) lithiation strains without fracture to some extent; other well-defined Si nanostructures including nanowires, nanotubes, porous structures and their composites with carbon materials have been proposed to alleviate volume expansion as well.
  • the cost for Si production is also a critical parameter to consider for its widespread application as anode material.
  • HEVs hybrid electrical vehicles
  • EV electrical vehicles
  • magnesiothermic reduction method is of great potential for large-scalable production based on its cheap raw material Mg powder and simple devices.
  • Diverse silicon with porous structure has been synthesized by magnesiothermic reduction method and exhibits good electrochemical performance.
  • massive heat will be released during the reactive process and results in a much higher reaction temperature than the set one.
  • the architectures of the silica precursor will be easily collapsed and agglomerated products will be simultaneously formed under a too high temperature. Meanwhile, some side reaction products Mg 2 Si and Mg 2 SiO 4 will significantly influence the electrochemical performance of the synthesized silicon.
  • the reduction of active material particle size to nano-scale or generate porous structure can help shorten the diffusion length of charge carriers, enhance the Li-ion diffusion coefficient, and therefore achieve faster reaction kinetics.
  • nano-sized or porous active materials have a large surface area, which results in a high irreversible capacity loss due to the formation of a solid electrode interface (SEI) .
  • SEI solid electrode interface
  • the irreversible reaction during the first lithiation also leads to a large irreversible capacity loss in initial cycle. This irreversible capacity loss consumes Li in the cathode, which decreases the capacity of the full cell.
  • additional or supplementary Li may be provided by the prelithiation of the anode. If the prelithiation of the anode is conducted, the irreversible capacity loss could be compensated in advance instead of Li consumption from the cathode. This results in higher efficiency and capacity of the cell.
  • the inventors of the present invention successfully develop a large-scale silicon production process to achieve a high reversible capacity by using an appropriate salt or composite salt as a heat absorbent and using the extremely price advantageous silica precursor in a thermal reduction process.
  • the present invention provides a method for producing silicon particles, said method including the following steps:
  • step 2) heating the mixture obtained from step 1) at a heating temperature of from the melting point of said reducing agent to lower than 800°C under a protective atmosphere;
  • the present invention relates to porous silicon particles, which have a bimodal pore size distribution of ⁇ 2 nm and 10 –30 nm.
  • the present invention relates to a silicon-carbon composite, which comprises a carbon coating layer as well as the silicon particles according to the present invention.
  • the present invention relates to an electrode material, which comprises the silicon-carbon composite according to the present invention.
  • the present invention relates to a battery, which comprises the electrode material according to the present invention.
  • the present invention relates to the use of the silicon-carbon composite according to the present invention as an electrode active material.
  • Figure 1 shows the XRD pattern of the silicon particles of Example 1
  • Figure 2 shows the cycling performances of the silicon particles of Example 1 (E1) and Comparison Example 1 (CE1) ;
  • Figure 3 shows the cycling performances of the silicon particles of Examples 1 ⁇ 7 (E1 ⁇ E7) and Comparison Examples 1 ⁇ 3 (CE1 ⁇ CE3) ;
  • Figure 4 shows the XRD patterns of the silicon particles of Example 3 (E3) , Example 6 (E6) , Example 5 (E5) , Example 2 (E2) , and Comparison Example 2 (CE2) ;
  • Figure 5 shows the SEM images of the silicon particles of Comparison Example 2 (CE2) , Example 2 (E2) , Example 5 (E5) , Example 6 (E6) , and Example 3 (E3) ;
  • Figure 6 shows the XRD patterns of the silicon particles of Example 7 (E7) and Comparison Example 3 (E3) ;
  • Figure 7 shows (a) the SEM and (b) the TEM images of the silicon particles of Example 8;
  • Figure 8 shows the N 2 -sorption isotherms of (a) the raw material porous SiO 2 and (b) the silicon particles of Example 8;
  • Figure 9 shows the pore size distribution of (a) the raw material porous SiO 2 and (b) the silicon particles of Example 8;
  • Figure 10 shows the cycling performances of the silicon particles of Examples 8 (E8) and the silicon-carbon composite of Example 9 (E9) ;
  • Figure 11 shows the rate capability of the silicon-carbon composite of Example 9
  • Figure 12 shows the cycling performances of the full cells of Example P1-E1;
  • Figure 13 shows the normalized energy densities of the full cells of Example P1-E1;
  • Figure 14 shows the cycling performances of the full cells of Example P1-E2;
  • Figure 15 shows the normalized energy densities of the full cells of Example P1-E2;
  • Figure 16 shows the cycling performances of the full cells of Example P1-E3 with the prelithiation degrees ⁇ of a) 0 and b) 22%;
  • Figure 17 shows the discharge/charge curve of the cell of Comparative Example P2-CE1, wherein “1” , “4” , “50” and “100” stand for the 1 st , 4 th , 50 th and 100 th cycle respectively;
  • Figure 18 shows the discharge/charge curve of the cell of Example P2-E1, wherein “1” , “4” , “50” and “100” stand for the 1 st , 4 th , 50 th and 100 th cycle respectively;
  • Figure 19 shows the cycling performances of the cells of a) Comparative Example P2-CE1 (dashed line) and b) Example P2-E1 (solid line) ;
  • Figure 20 shows the average charge voltage a) and the average discharge voltage b) of the cell of Comparative Example P2-CE1;
  • Figure 21 shows the average charge voltage a) and the average discharge voltage b) of the cell of Example P2-E1.
  • the present invention relates to a method for producing silicon particles, said method including the following steps:
  • step 2) heating the mixture obtained from step 1) at a heating temperature of from the melting point of said reducing agent to lower than 800°C under a protective atmosphere;
  • the melting temperature of said salt or the liquidus temperature of said composite salt ranges from a temperature higher than the heating temperature of step 2) to 800°C.
  • the silica source material can be dispersed in an aqueous solution of the heat absorbent under stirring at room temperature.
  • the mixture can be heated to 80°C under vigorous stirring, dried under vacuum at 90°C to remove water, and then homogenized by hand-milling in an agate mortar. Then the mixture and magnesium and/or aluminium powder can be ground together in an agate mortar.
  • the melting temperature of said salt or the liquidus temperature of said composite salt can be 660 –800°C, preferably 665 –790°C, more preferably 670 –780°C, for example 680°C, 690°C, 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, or 770°C.
  • the type of said salt or composite salt is not particularly limited.
  • said salt or composite salt shall not be decomposed under the heating temperature of step 2) , and preferably can be inorganic salts or composite salts, more preferably inorganic halides.
  • Said salt or composite salt preferably does not contain water of crystallization, or is not susceptible to be hydrated.
  • said heat absorbent can be one or more selected from the group consisting of KCl;
  • KCl/LiCl with a LiCl content of ⁇ 25 mol. %, preferably ⁇ 20 mol. %, more preferably ⁇ 10 mol. %, particular preferably ⁇ 5 mol. %;
  • the weight ratio of said silica source material to said heat absorbent can be 3 : 7 –7 : 3, preferably 2 : 3 –3 : 2, more preferably 4 : 5 –1 : 1, calculated on the basis of SiO 2 in said silica source material.
  • said silica source material can be one or more selected from the group consisting of zeolite, diatom, SiO 2 nanopowder, and porous SiO 2 , preferably porous SiO 2 , such as 350, available from EVONIK.
  • the amount of said reducing agent used can be 1 –1.5 times, preferably 1 –1 : 1.3 times, more preferably 1 –1.1 times the stoichiometry according to the reaction between SiO 2 and said reducing agent.
  • step 2) the mixture obtained from step 1) can be heated at a heating temperature of at least 2°C, preferably 5°C, more preferably 10°C higher than the melting point of said reducing agent, for 1 –6 hours, preferably 2 –3 hours, for example at a heating rate of 2°C/min, 5°C/min, or 10°C/min, under a protective atmosphere, for example Ar/H 2 (5 vol. %) .
  • the heating rate and the heating duration are not particularly limited.
  • the furnace used here is not particularly limited. For examle an ordinary tube furnace can be used for heating the mixture obtained from step 1) . In case of large-scale production of silicon particles, it would be preferred to use a tube furnace rotatable along its longitudinal axis, namely a rotation furnace.
  • the heat absorbent can be removed by immersing the product of step 2) into water and filtering, and can also be recycled by drying the filtrate. And then the oxidation products of said reducing agent can be removed by immersing the filter residue into 2 M HCl solution and stirred for 12 hours.
  • HF can be used to rinse the product obtained from step 3) , so as to remove unreacted SiO 2 and/or SiO 2 newly grown on the surface of the silicon particles during step 3) .
  • the secondary particle size of the silicon particles obtained from step 2) is relatively small, for example less than 0.5 ⁇ m, so that the surface of the silicon particles might be oxidized again during step 3) , it would be preferred to use HF to rinse the product obtained from step 3) .
  • the product obtained from step 3) can be immersed into 1 wt. %HF/EtOH (10 vol. %) solution and stirred for 15 min.
  • the present invention further relates to porous silicon particles, which have a bimodal pore size distribution of ⁇ 2 nm and 10 –30 nm.
  • said porous silicon particles have a BET specific surface area of greater than 300 m 2 /g, preferably greater than 400 m 2 /g, more preferably greater than 500 m 2 /g.
  • micropores of ⁇ 2 nm in the porous silicon particles are supposed to be derived from porous SiO 2 as the silica source material.
  • the BET specific surface area of the porous silicon particles is one order of magnitude greater than that of porous SiO 2 as the silica source material.
  • porous SiO 2 as the silica source material may contain quite a number of closed micropores, and these closed micropores may be opened during the vigorous reduction reaction and may contribute to the specific surface area.
  • the primary particle size of said porous silicon particles can be 30 –100 nm, preferably 35 –80 nm; and the secondary particle size (agglomerate particle size) of said porous silicon particles can be 1 –10 ⁇ m, prefaerably 3 –6 ⁇ m.
  • the pore volume of said porous silicon particles can be 0.1 –1.5 cm 3 /g.
  • said porous silicon particles can be prepared by the method according to the present invention, in case that porous SiO 2 is used as the silica source material.
  • the present invention relates to a silicon-carbon composite, which comprises a carbon coating layer as well as the silicon particles according to the present invention.
  • the thickness of the carbon coating layer can be 1 –10 nm.
  • the present invention relates to an electrode material, which comprises the silicon-carbon composite according to the present invention.
  • the present invention relates to the use of the silicon-carbon composite according to the present invention as an electrode active material.
  • the present invention relates to a battery, which comprises the electrode material according to the present invention.
  • a prelithiation when the cathode efficiency is higher than the anode efficiency, a prelithiation can effectively increase the cell capacity via increasing the initial Coulombic efficiency. In this case, maximum energy density can be reached. For a cell, in which the loss of lithium during cycling may occur, prelithiation can also improve the cycling performance when an over-prelithiation is applied.
  • the over-prelithiation provides a reservoir of lithium in the whole electrochemical system and the extra lithium in the anode compensates the possible lithium consumption from the cathode during cycling.
  • the higher prelithiation degree the better cycling performance could be achieved.
  • a higher prelithiation degree involves a much larger anode. Therefore, the cell energy density will decrease due to the increased weight and volume of the anode. Therefore, the prelithiation degree should be carefully controlled to balance the cycling performance and the energy density.
  • the present invention relates to a lithium-ion battery comprising a cathode, an electrolyte, and an anode, wherein the anode comprises the electrode material according to the present invention, and the initial surface capacity a of the cathode and the initial surface capacity b of the anode satisfy the relation formulae
  • ⁇ is the prelithiation degree of the anode
  • ⁇ 1 is the initial coulombic efficiency of the cathode
  • ⁇ 2 is the initial coulombic efficiency of the anode.
  • the term “surface capacity” means the specific surface capacity in mAh/cm 2 , the electrode capacity per unit of the electrode surface area.
  • the term “initial capacity of the cathode” means the initial delithiation capacity of the cathode, and the term “initial capacity of the anode” means the initial lithiation capacity of the anode.
  • the term “prelithiation degree” ⁇ of the anode can be calculated by (b –a ⁇ x) /b, wherein x is the balance of the anode capacity after prelithiation and the cathode capacity.
  • the anode capacity is usually designed slightly greater than the cathode capacity, and the balance of the anode capacity after prelithiation and the cathode capacity can be selected from greater than 1 to 1.2, preferably from 1.05 to 1.15, more preferably from 1.08 to 1.12, particular preferably about 1.1.
  • the initial surface capacity a of the cathode and the initial surface capacity b of the anode satisfy the relation formulae
  • the prelithiation degree of the anode can be defined as
  • c is the depth of discharge (DoD) of the anode.
  • the active material of the anode can be selected from the group consisting of carbon, silicon, silicon intermetallic compound, silicon oxide, silicon alloy and mixtures thereof.
  • the active material of the cathode can be selected from the group consisting of lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium nickel cobalt manganese oxide, and mixtures thereof.
  • the present invention relates to a method for producing a lithium-ion battery comprising a cathode, an electrolyte, and an anode, wherein the anode comprises the electrode material according to the present invention, and said method includes the following steps:
  • ⁇ is the prelithiation degree of the anode
  • ⁇ 1 is the initial coulombic efficiency of the cathode
  • ⁇ 2 is the initial coulombic efficiency of the anode.
  • the term “surface capacity” means the specific surface capacity in mAh/cm 2 , the electrode capacity per unit of the electrode surface area.
  • the term “initial capacity of the cathode” means the initial delithiation capacity of the cathode, and the term “initial capacity of the anode” means the initial lithiation capacity of the anode.
  • the term “prelithiation degree” ⁇ of the anode can be calculated by (b –a ⁇ x) /b, wherein x is the balance of the anode capacity after prelithiation and the cathode capacity.
  • the anode capacity is usually designed slightly greater than the cathode capacity, and the balance of the anode capacity after prelithiation and the cathode capacity can be selected from greater than 1 to 1.2, preferably from 1.05 to 1.15, more preferably from 1.08 to 1.12, particular preferably about 1.1.
  • the prelithiation process is not particularly limited.
  • the lithiation of the anode active material substrate can be carried out for example in several different ways.
  • a physical process includes deposition of a lithium coating layer on the surface of the anode active material substrate such as silicon particles, thermally induced diffusion of lithium into the substrate such as silicon particles, or spray of stabilized Li powder onto the anode tape.
  • An electrochemical process includes using silicon particles and a lithium metal plate as the electrodes, and applying an electrochemical potential so as to intercalate Li + ions into the bulk of the silicon particles.
  • An alternative electrochemical process includes assembling a half cell with silicon particles and Li metal foil electrodes, charging the half cell, and disassembling the half cell to obtain lithiated silicon particles.
  • the initial surface capacity a of the cathode and the initial surface capacity b of the anode satisfy the relation formulae
  • the prelithiation degree of the anode can be defined as
  • c is the depth of discharge (DoD) of the anode.
  • the active material of the anode can be selected from the group consisting of carbon, silicon, silicon intermetallic compound, silicon oxide, silicon alloy and mixtures thereof.
  • the active material of the cathode can be selected from the group consisting of lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium nickel cobalt manganese oxide, and mixtures thereof.
  • Prior art prelithiation methods often involve a treatment of coated anode tape. This could be an electrochemical process, or physical contact of the anode with stabilized lithium metal powder.
  • these prelithiation procedure requires additional steps to the current battery production method.
  • the subsequent battery production procedure requires an environment with well-controlled humidity, which results in an increased cost for the cell production.
  • the present invention provides an alternative method of in-situ prelithiation.
  • the lithium source for prelithaition comes from the cathode.
  • the first formation cycle by increasing the cut-off voltage of the full cell, additional amount of lithium is extracted from the cathode; by controlling the discharge capacity, the additional lithium extracted from the cathode is stored at the anode, and this is ensured in the following cycles by maintaining the upper cut-off voltage the same as in the first cycle.
  • the present invention relates to a lithium-ion battery comprising a cathode, an electrolyte, and an anode, characterized in that the anode comprises the electrode material according to the present invention, and said lithium-ion battery is subjected to a formation process, wherein said formation process includes an initial formation cycle comprising the following steps:
  • the term “formation process” means the initial one or more charging/discharging cycles of the lithium-ion battery for example at 0.1C, once the lithium-ion battery is assembled. During this process, a stable solid-electrolyte-inter-phase (SEI) layer can be formed at the anode.
  • SEI solid-electrolyte-inter-phase
  • the battery in step a) can be charged to a cut off voltage which is up to 0.8 V greater than the nominal charge cut off voltage of the battery, preferably 0.1 ⁇ 0.5 V greater than the nominal charge cut off voltage of the battery, more preferably 0.2 ⁇ 0.4 V greater than the nominal charge cut off voltage of the battery, particular preferably about 0.3 V greater than the nominal charge cut off voltage of the battery.
  • a lithium-ion battery with the typical cathode materials of cobalt, nickel, manganese and aluminum typically charges to 4.20V ⁇ 50mV as the nominal charge cut off voltage. Some nickel-based batteries charge to 4.10V ⁇ 50mV.
  • the nominal charge cut off voltage of the battery can be about 4.2 V ⁇ 50mV, and the nominal discharge cut off voltage of the battery can be about 2.5 V ⁇ 50mV.
  • the Coulombic efficiency of the cathode in the initial formation cycle can be 40% ⁇ 80%, preferably 50% ⁇ 70%.
  • said formation process further includes one or two or more formation cycles, which are carried out in the same way as the initial formation cycle.
  • the electrolyte comprises one or more fluorinated carbonate compounds as a nonaqueous organic solvent
  • the electrochemical window of the electrolyte can be broadened, and the safety of the battery can still be ensured at a charge cut off voltage of 5V or even higher.
  • an additional cathode capacity can preferably be supplemented to the nominal initial surface capacity of the cathode.
  • the term “nominal initial surface capacity” a of the cathode means the nominally designed initial surface capacity of the cathode.
  • the term “surface capacity” means the specific surface capacity in mAh/cm 2 , the electrode capacity per unit of the electrode surface area.
  • the term “initial capacity of the cathode” means the initial delithiation capacity of the cathode, and the term “initial capacity of the anode” means the initial lithiation capacity of the anode.
  • the relative increment r of the initial surface capacity of the cathode over the nominal initial surface capacity a of the cathode and the cut off voltage V off satisfy the following linear equation with a tolerance of ⁇ 5%, ⁇ 10%, or ⁇ 20%
  • the relative increment r of the initial surface capacity of the cathode over the nominal initial surface capacity a of the cathode and the cut off voltage V off satisfy the following quadratic equation with a tolerance of ⁇ 5%, ⁇ 10%, or ⁇ 20%
  • the nominal initial surface capacity a of the cathode and the initial surface capacity b of the anode satisfy the relation formulae
  • ⁇ is the prelithiation degree of the anode
  • ⁇ 2 is the initial coulombic efficiency of the anode.
  • the term “prelithiation degree” ⁇ of the anode can be calculated by (b –a ⁇ x) /b, wherein x is the balance of the anode capacity after prelithiation and the cathode capacity.
  • the anode capacity is usually designed slightly greater than the cathode capacity, and the balance of the anode capacity after prelithiation and the cathode capacity can be selected from greater than 1 to 1.2, preferably from 1.05 to 1.15, more preferably from 1.08 to 1.12, particular preferably about 1.1.
  • the prelithiation degree of the anode can be defined as
  • ⁇ 1 is the initial coulombic efficiency of the cathode
  • c is the depth of discharge (DoD) of the anode.
  • the electrolyte comprises one or more fluorinated carbonate compounds, preferably fluorinated cyclic or acyclic carbonate compounds, as a nonaqueous organic solvent.
  • the fluorinated carbonate compounds can be selected from the group consisting of fluorinated ethylene carbonate, fluorinated propylene carbonate, fluorinated dimethyl carbonate, fluorinated methyl ethyl carbonate, and fluorinated diethyl carbonate, in which the “fluorinated” carbonate compounds can be understood as “monofluorinated” , “difluorinated” , “trifluorinated” , “tetrafluorinated” , and “perfluorinated” carbonate compounds.
  • the fluorinated carbonate compounds can be selected from the group consisting of monofluoroethylene carbonate, 4, 4-difluoro ethylene carbonate, 4, 5-difluoro ethylene carbonate, 4, 4, 5-trifluoroethylene carbonate, 4, 4, 5, 5-tetrafluoroethylene carbonate, 4-fluoro-4-methyl ethylene carbonate, 4, 5-difluoro-4-methyl ethylene carbonate, 4-fluoro-5-methyl ethylene carbonate, 4, 4-difluoro-5-methyl ethylene carbonate, 4- (fluoromethyl) -ethylene carbonate, 4- (difluoromethyl) -ethylene carbonate, 4- (trifluoromethyl) -ethylene carbonate, 4- (fluoromethyl) -4-fluoro ethylene carbonate, 4- (fluoromethyl) -5-fluoro ethylene carbonate, 4, 4, 5-trifluoro-5-methyl ethylene carbonate, 4-fluoro-4, 5-dimethyl ethylene carbonate,
  • the content of the fluorinated carbonate compounds can be 10 ⁇ 100 vol. %, preferably 30 ⁇ 100 vol. %, more preferably 50 ⁇ 100 vol. %, particular preferably 80 ⁇ 100 vol. %, based on the total nonaqueous organic solvent.
  • the active material of the anode can be selected from the group consisting of carbon, silicon, silicon intermetallic compound, silicon oxide, silicon alloy and mixtures thereof.
  • the active material of the cathode can be selected from the group consisting of lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium nickel cobalt manganese oxide, and mixtures thereof.
  • said lithium-ion battery after being subjected to the formation process, said lithium-ion battery can still be charged to a cut off voltage V off , which is greater than the nominal charge cut off voltage of the battery, and be discharged to the nominal discharge cut off voltage of the battery.
  • said lithium-ion battery after being subjected to the formation process, can still be charged to a cut off voltage V off , which is up to 0.8 V greater than the nominal charge cut off voltage of the battery, more preferably 0.1 ⁇ 0.5 V greater than the nominal charge cut off voltage of the battery, particular preferably 0.2 ⁇ 0.4 V greater than the nominal charge cut off voltage of the battery, especially preferably about 0.3 V greater than the nominal charge cut off voltage of the battery, and be discharged to the nominal discharge cut off voltage of the battery.
  • V off is up to 0.8 V greater than the nominal charge cut off voltage of the battery, more preferably 0.1 ⁇ 0.5 V greater than the nominal charge cut off voltage of the battery, particular preferably 0.2 ⁇ 0.4 V greater than the nominal charge cut off voltage of the battery, especially preferably about 0.3 V greater than the nominal charge cut off voltage of the battery, and be discharged to the nominal discharge cut off voltage of the battery.
  • the present invention relates to a method for producing a lithium-ion battery comprising a cathode, an electrolyte, and an anode, wherein the anode comprises the electrode material according to the present invention, and said method includes the following steps:
  • the term “formation process” means the initial one or more charging/discharging cycles of the lithium-ion battery for example at 0.1C, once the lithium-ion battery is assembled. During this process, a stable solid-electrolyte-inter-phase (SEI) layer can be formed at the anode.
  • SEI solid-electrolyte-inter-phase
  • the battery in step a) can be charged to a cut off voltage which is up to 0.8 V greater than the nominal charge cut off voltage of the battery, preferably 0.1 ⁇ 0.5 V greater than the nominal charge cut off voltage of the battery, more preferably 0.2 ⁇ 0.4 V greater than the nominal charge cut off voltage of the battery, particular preferably about 0.3 V greater than the nominal charge cut off voltage of the battery.
  • a lithium-ion battery with the typical cathode materials of cobalt, nickel, manganese and aluminum typically charges to 4.20V ⁇ 50mV as the nominal charge cut off voltage. Some nickel-based batteries charge to 4.10V ⁇ 50mV.
  • the nominal charge cut off voltage of the battery can be about 4.2 V ⁇ 50mV, and the nominal discharge cut off voltage of the battery can be about 2.5 V ⁇ 50mV.
  • the Coulombic efficiency of the cathode in the initial formation cycle can be 40% ⁇ 80%, preferably 50% ⁇ 70%.
  • said formation process further includes one or two or more formation cycles, which are carried out in the same way as the initial formation cycle.
  • an additional cathode capacity can preferably be supplemented to the nominal initial surface capacity of the cathode.
  • the term “nominal initial surface capacity” a of the cathode means the nominally designed initial surface capacity of the cathode.
  • the term “surface capacity” means the specific surface capacity in mAh/cm 2 , the electrode capacity per unit of the electrode surface area.
  • the term “initial capacity of the cathode” means the initial delithiation capacity of the cathode, and the term “initial capacity of the anode” means the initial lithiation capacity of the anode.
  • the relative increment r of the initial surface capacity of the cathode over the nominal initial surface capacity a of the cathode and the cut off voltage V off satisfy the following linear equation with a tolerance of ⁇ 5%, ⁇ 10%, or ⁇ 20%
  • the relative increment r of the initial surface capacity of the cathode over the nominal initial surface capacity a of the cathode and the cut off voltage V off satisfy the following quadratic equation with a tolerance of ⁇ 5%, ⁇ 10%, or ⁇ 20%
  • the nominal initial surface capacity a of the cathode and the initial surface capacity b of the anode satisfy the relation formulae
  • ⁇ is the prelithiation degree of the anode
  • ⁇ 2 is the initial coulombic efficiency of the anode.
  • the term “prelithiation degree” ⁇ of the anode can be calculated by (b –a ⁇ x) /b, wherein x is the balance of the anode capacity after prelithiation and the cathode capacity.
  • the anode capacity is usually designed slightly greater than the cathode capacity, and the balance of the anode capacity after prelithiation and the cathode capacity can be selected from greater than 1 to 1.2, preferably from 1.05 to 1.15, more preferably from 1.08 to 1.12, particular preferably about 1.1.
  • the prelithiation degree of the anode can be defined as
  • ⁇ 1 is the initial coulombic efficiency of the cathode
  • c is the depth of discharge (DoD) of the anode.
  • the electrolyte comprises one or more fluorinated carbonate compounds, preferably fluorinated cyclic or acyclic carbonate compounds, as a nonaqueous organic solvent.
  • the fluorinated carbonate compounds can be selected from the group consisting of fluorinated ethylene carbonate, fluorinated propylene carbonate, fluorinated dimethyl carbonate, fluorinated methyl ethyl carbonate, and fluorinated diethyl carbonate, in which the “fluorinated” carbonate compounds can be understood as “monofluorinated” , “difluorinated” , “trifluorinated” , “tetrafluorinated” , and “perfluorinated” carbonate compounds.
  • the fluorinated carbonate compounds can be selected from the group consisting of monofluoroethylene carbonate, 4, 4-difluoro ethylene carbonate, 4, 5-difluoro ethylene carbonate, 4, 4, 5-trifluoroethylene carbonate, 4, 4, 5, 5-tetrafluoroethylene carbonate, 4-fluoro-4-methyl ethylene carbonate, 4, 5-difluoro-4-methyl ethylene carbonate, 4-fluoro-5-methyl ethylene carbonate, 4, 4-difluoro-5-methyl ethylene carbonate, 4- (fluoromethyl) -ethylene carbonate, 4- (difluoromethyl) -ethylene carbonate, 4- (trifluoromethyl) -ethylene carbonate, 4- (fluoromethyl) -4-fluoro ethylene carbonate, 4- (fluoromethyl) -5-fluoro ethylene carbonate, 4, 4, 5-trifluoro-5-methyl ethylene carbonate, 4-fluoro-4, 5-dimethyl ethylene carbonate, 4, 5-difluoro-4, 5-dimethyl ethylene carbonate,
  • the content of the fluorinated carbonate compounds can be 10 ⁇ 100 vol. %, preferably 30 ⁇ 100 vol. %, more preferably 50 ⁇ 100 vol. %, particular preferably 80 ⁇ 100 vol. %, based on the total nonaqueous organic solvent.
  • the active material of the anode can be selected from the group consisting of carbon, silicon, silicon intermetallic compound, silicon oxide, silicon alloy and mixtures thereof.
  • the active material of the cathode can be selected from the group consisting of lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium nickel cobalt manganese oxide, and mixtures thereof.
  • KCl (melting temperature: 771°C) was used as the heat absorbent.
  • 0.5 g of nano-SiO 2 power (Aladdin Chemical, 15 nm) was firstly dispersed to an aqueous KCl solution (0.1 g/mL) under stirring at room temperature.
  • the ratio of silica to KCl in weight was 30: 70.
  • the mixture was heated to 80°C under vigorous stirring followed by drying under vacuum at 90°C to remove water. Dried nano-SiO 2 /KCl powder was then homogenized by hand-milling in an agate mortar.
  • the obtained mixture was loaded in an alundum boat and placed in the constant temperature zone of a tube furnace. And then the furnace was heated from room temperature to 650°C at a rate of 2°C/min and kept at 650°C for 4 hours under Ar (95 vol. %) /H 2 (5 vol. %) mixed atmosphere. Finally, after cooling to room temperature, a uniform powder in yellow color was obtained.
  • X-Ray Diffraction was used to analyse the composition, the crystallinity and the crystal size of the products.
  • Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were employed to characterize the size and structure of the products.
  • N 2 -sorption isotherms were used to analyse the pore size distribution of the products.
  • Figure 1 shows the XRD pattern of the silicon particles of Example 1. It can be seen that there was no impurity in the silicon particles of Example 1.
  • the electrochemical performances of the as-prepared composites were tested using two-electrode coin-type cells.
  • the working electrodes were prepared by pasting a mixture of active material, Super P conductive carbon black (40 nm, Timical) and styrene butadiene rubber/sodium carboxymethyl cellulose (SBR/SCMC, 3: 5 by weight) as binder at a weight ratio of 60: 20: 20. After coating the mixture onto pure Cu foil, the electrodes were dried, cut to ⁇ 12 mm sheets, and then further dried at 60°C in vacuum for 4 hours.
  • the CR2016 coin cells were assembled in an argon-filled glove box (MB-10 compact, MBraun) using 1 M LiPF 6 /EC+DMC (1: 1 by volume, ethylene carbonate (EC) , dimethyl carbonate (DMC)) as electrolyte, including 10%Fluoroethylene carbonate (FEC) , ENTEK ET20-26 as separator, and pure lithium foil as counter electrode.
  • MB-10 compact, MBraun 1 M LiPF 6 /EC+DMC (1: 1 by volume, ethylene carbonate (EC) , dimethyl carbonate (DMC)) as electrolyte, including 10%Fluoroethylene carbonate (FEC) , ENTEK ET20-26 as separator, and pure lithium foil as counter electrode.
  • the cycling performances were evaluated on a LAND battery test system (Wuhan Kingnuo Electronics Co., Ltd., China) at 25°C, wherein in the cycling performance test the coin cells were discharged at 100 mA g -1 for the initial two cycles and at 300 mA g -1 (Examples 1 ⁇ 7 and Comparison Examples 1 ⁇ 3) or 1000 mA g -1 (Examples 8 ⁇ 9) for the following cycles.
  • the cut-off voltage was 0.01 V versus Li/Li + for discharge (Li insertion) and 1.2 V versus Li/Li + for charge (Li extraction) .
  • Figures 2 and 3 show the cycling performance of the silicon particles of Example 1.
  • Comparative Example 1 was carried out similar to Example 1, except that no KCl was used as the heat absorbent.
  • Figures 2 and 3 show the cycling performance of the silicon particles of Comparison Example 1. It can be seen that the electrochemical performance of the silicon particles can be greatly enhanced by using a salt or composite salt as the heat absorbent.
  • Example 2 was carried out similar to Example 1, except that 0.54 g of nano-SiO 2 power was used, and the weight ratio of silica to the heat absorbent was 45: 55.
  • Figure 3 shows the cycling performance of the silicon particles of Example 2.
  • Figure 4 shows the XRD patterns of the silicon particles of Example 2.
  • Figure 5 shows the SEM images of the silicon particles of Example 2.
  • Comparative Example 2 was carried out similar to Example 2, except that NaCl (melting temperature: 801°C) was used as the heat absorbent.
  • Figure 3 shows the cycling performance of the silicon particles of Comparative Example 2.
  • Figure 4 shows the XRD patterns of the silicon particles of Comparison Example 2.
  • Figure 5 shows the SEM images of the silicon particles of Comparison Example 2.
  • the inventors of the present invention believed that the surface of the silicon particles of Comparison Example 2 was too active and might be oxidized before being used as the electrode material, even though HF was used to rinse the product.
  • Example 3 was carried out similar to Example 2, except that KCl/NaCl with a NaCl content of 10 mol. %was used as the heat absorbent, the liquidus temperature of which can be determined from the binary diagram of KCl/NaCl as about 720°C.
  • Figure 3 shows the cycling performance of the silicon particles of Example 3.
  • Figure 4 shows the XRD patterns of the silicon particles of Example 3.
  • Figure 5 shows the SEM images of the silicon particles of Example 3.
  • Example 4 was carried out similar to Example 2, except that KCl/NaCl with a NaCl content of 72 mol. %was used as the heat absorbent, the liquidus temperature of which can be determined from the binary diagram of KCl/NaCl as about 670°C.
  • Figure 3 shows the cycling performance of the silicon particles of Example 4.
  • Example 5 was carried out similar to Example 2, except that KCl/NaCl with a NaCl content of 90 mol. %was used as the heat absorbent, the liquidus temperature of which can be determined from the binary diagram of KCl/NaCl as about 715°C.
  • Figure 3 shows the cycling performance of the silicon particles of Example 5.
  • Figure 4 shows the XRD patterns of the silicon particles of Example 5.
  • Figure 5 shows the SEM images of the silicon particles of Example 5.
  • Example 6 was carried out similar to Example 2, except that KCl/LiCl with a LiCl content of 5 mol. %was used as the heat absorbent, the liquidus temperature of which can be determined from the binary diagram of KCl/LiCl as about 750°C.
  • Figure 3 shows the cycling performance of the silicon particles of Example 6.
  • Figure 4 shows the XRD patterns of the silicon particles of Example 6.
  • the crystal size of the silicon particles can be calculated based on the XRD patterns according to Scherrer formula.
  • the sequence of the crystal size of the silicon particles were: CE2 ⁇ E2 ⁇ E5 ⁇ E6 ⁇ E3.
  • Figure 5 shows the SEM images of the silicon particles of Example 6.
  • the particle size can be measured based on the SEM images of the silicon particles.
  • Example 7 was carried out similar to Example 2, except that 3.83 g of nano-SiO 2 power was used and a rotation furnace was used instead of the tube furnace.
  • Figure 3 shows the cycling performance of the silicon particles of Example 7.
  • Figure 6 shows the XRD patterns of the silicon particles of Example 7.
  • Comparative Example 3 was carried out similar to Example 1, except that 2 g of nano-SiO 2 power was used, NaCl (melting temperature: 801°C) was used as the heat absorbent and the weight ratio of silica to the heat absorbent was 1: 10. Such a weight ratio was used according to Luo, W. ’s synthesis method. The high content of NaCl resulted in a low capacity.
  • Figure 3 shows the cycling performance of the silicon particles of Comparative Example 3.
  • Figure 6 shows the XRD patterns of the silicon particles of Comparison Example 3. It can be seen that the product of Comparative Example 3 contained SiO 2 impurity. The peaks at 69° and 76° were too weak, which demonstrated that the crystallinity of the product of Comparative Example 3 was relatively low. In addition, the FWHM of the product of Comparative Example 3 was broader than that of Example 7, which demonstrated that the crystal size of the product of Comparative Example 3 was smaller than that of Example 7.
  • the inventors of the present invention believed that the surface of the silicon particles of Comparison Example 3 was too active and might be oxidized before being used as the electrode material, even though HF was used to rinse the product.
  • Example 8 was carried out similar to Example 7, except that porous SiO 2 ( 350, available from EVONIK) was used as the silica source material to obtain porous silicon particles as the product and that HF was not used to rinse the product.
  • porous SiO 2 350, available from EVONIK
  • 350 is a macroporous silica with low surface area and an average pore size in the 150 nm range. Its specific surface area (N 2 , multipoint, following ISO 9277) is 55 m 2 /g. Its particle size (d50, laser diffraction, following ISO 13320-1) is 4.5 ⁇ m.
  • Figure 7 shows (a) the SEM and (b) the TEM images of the silicon particles of Example 8.
  • Figure 8 shows the N 2 -sorption isotherms of (a) the raw material porous SiO 2 and (b) the silicon particles of Example 8.
  • Figure 9 shows the pore size distribution of (a) the raw material porous SiO 2 and (b) the silicon particles of Example 8. It can be seen that the porous silicon particles of Example 8 have a bimodal pore size distribution of ⁇ 2 nm and 10 –30 nm.
  • Figure 10 shows the cycling performances of the silicon particles of Examples 8.
  • a carbon coating was applied on the porous silicon particles obtained from Example 8 by CVD, and the carbon content was 26 wt. %and the carbon layer thickness is ca. 6nm.
  • Figure 10 shows the cycling performances of the silicon-carbon composite of Example 9.
  • Figure 11 shows the rate capability of the silicon-carbon composite of Example 9.
  • Active material of the cathode NCM-111 from BASF, and HE-NCM prepared according to the method as described in WO 2013/097186 A1;
  • Active material of the anode a mixture (1: 1 by weight) of silicon nanoparticle with a diameter of 50 nm from Alfa Aesar and graphite from Shenzhen Kejingstar Technology Ltd. ;
  • Carbon additives flake graphite KS6L and Super P Carbon Black C65 from Timcal;
  • Electrolyte 1M LiPF 6 /EC (ethylene carbonate) +DMC (dimethyl carbonate) (1: 1 by volume) ; Separator: PP/PE/PP membrane Celgard 2325.
  • anode/Li half cells were assembled in form of 2016 coin cell in an Argon-filled glove box (MB-10 compact, MBraun) , wherein lithium metal was used as the counter electrode.
  • the assembled anode/Li half cells were discharged to the designed prelithiation degree ⁇ as given in Table P1-E1, so as to put a certain amout of Li + ions in the anode, i.e., the prelithiation of the anode.
  • the half cells were disassembled.
  • the prelithiated anode and NCM-111 cathode were assembled to obtain 2032 coin full cells.
  • the cycling performances of the full cells were evaluated at 25°C on an Arbin battery test system at 0.1C for formation and at 1C for cycling.
  • Figure 12 shows the cycling performances of the full cells of Groups G0, G1, G2, G3, and G4 of Example P1-E1.
  • Figure 13 shows a) the volumetric energy densities and b) the gravimetric energy densities of the full cells of Groups G0, G1, G2, G3, and G4 in Example P1-E1.
  • Group G1 with 5.6%prelithiation degree shows a higher energy density due to the higher capacity.
  • the energy density decreases to some extend but still has more than 90%energy density of G0 when prelithiation degree reaches 34.6%in G4.
  • Example P1-E2 was carried out similar to Example P1-E1, except that HE-NCM was used as the cathode active material and the corresponding parameters were given in Table P1-E2.
  • Figure 14 shows the cycling performances of the full cells of Groups G0, G1, and G2 of Example P1-E2.
  • Figure 15 shows a) the volumetric energy densities and b) the gravimetric energy densities of the full cells of Groups G0, G1, and G2 of Example P1-E2. It can been seen from Table P1-E2 that the initial Coulombic efficiencies of the full cells were increased from 85%to 95%in case of the prelithiation. Although larger anodes were used for prelithiation, the energy density did not decrease, or even a higher energy density was reached, compared with non-prelithiation in G0. Moreover, the cycling performances were greatly improved, because the Li loss during cycling was compensated by the reserved Li.
  • Example P1-E3 was carried out similar to Example P1-E1, except that pouch cells were assembled instead of coin cells, and the corresponding prelithiation degrees ⁇ of the anode were a) 0 and b) 22%.
  • Figure 16 shows the cycling performances of the full cells of Example P1-E3 with the prelithiation degrees ⁇ of a) 0 and b) 22%. It can been seen that the cycling performance was much improved in case of the prelithiation.
  • Cathode 96.5 wt. %of NCM-111 from BASF, 2 wt. %of PVDF Solef 5130 from Sovey, 1 wt. %of Super P Carbon Black C65 from Timcal, 0.5 wt. %of conductive graphite KS6L from Timcal;
  • Anode 40 wt. %of Silicon from Alfa Aesar, 40 wt. %of graphite from BTR, 10 wt. %of NaPAA, 8 wt. %of conductive graphite KS6L from Timcal, 2 wt. %of Super P Carbon Black C65 from Timcal;
  • Electrolyte 1M LiPF 6 /EC+DMC (1: 1 by volume, ethylene carbonate (EC) , dimethyl carbonate (DMC) , including 30 vol. %of fluoroethylene carbonate (FEC) , based on the total nonaqueous organic solvent) ;
  • a pouch cell was assembled with a cathode initial capacity of 3.83 mAh/cm 2 and an anode initial capacity of 4.36 mAh/cm 2 in an Argon-filled glove box (MB-10 compact, MBraun) .
  • the cycling performance was evaluated at 25°C on an Arbin battery test system at 0.1C for formation and at 1C for cycling, wherein the cell was charged to the nominal charge cut off voltage 4.2 V, and discharged to the nominal discharge cut off voltage 2.5 V or to a cut off capacity of 3.1 mAh/cm 2 .
  • the calculated prelithiation degree ⁇ of the anode was 0.
  • Figure 17 shows the discharge/charge curve of the cell of Comparative Example P2-CE1, wherein “1” , “4” , “50” and “100” stand for the 1 st , 4 th , 50 th and 100 th cycle respectively.
  • Figure 19 shows the cycling performances of the cells of a) Comparative Example P2-CE1 (dashed line) .
  • Figure 20 shows the average charge voltage a) and the average discharge voltage b) of the cell of Comparative Example P2-CE1.
  • a pouch cell was assembled with a cathode initial capacity of 3.73 mAh/cm 2 and an anode initial capacity of 5.17 mAh/cm 2 in an Argon-filled glove box (MB-10 compact, MBraun) .
  • the cycling performance was evaluated at 25°C on an Arbin battery test system at 0.1C for formation and at 1C for cycling, wherein the cell was charged to a cut off voltage of 4.5 V, which was 0.3 V greater than the nominal charge cut off voltage, and discharged to the nominal discharge cut off voltage 2.5 V or to a cut off capacity of 3.1 mAh/cm 2 .
  • the calculated prelithiation degree ⁇ of the anode was 21%.
  • Figure 18 shows the discharge/charge curve of the cell of Example P2-E1, wherein “1” , “4” , “50” and “100” stand for the 1 st , 4 th , 50 th and 100 th cycle respectively.
  • Figure 19 shows the cycling performances of the cells of b) Example P2-E1 (solid line) .
  • Figure 21 shows the average charge voltage a) and the average discharge voltage b) of the cell of Example P2-E1.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Electrochemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Battery Electrode And Active Subsutance (AREA)
PCT/CN2016/085848 2016-06-15 2016-06-15 Porous silicon particles and a method for producing silicon particles WO2017214882A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201680035058.7A CN107848809B (zh) 2016-06-15 2016-06-15 多孔硅颗粒及生产硅颗粒的方法
PCT/CN2016/085848 WO2017214882A1 (en) 2016-06-15 2016-06-15 Porous silicon particles and a method for producing silicon particles

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2016/085848 WO2017214882A1 (en) 2016-06-15 2016-06-15 Porous silicon particles and a method for producing silicon particles

Publications (1)

Publication Number Publication Date
WO2017214882A1 true WO2017214882A1 (en) 2017-12-21

Family

ID=60663869

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2016/085848 WO2017214882A1 (en) 2016-06-15 2016-06-15 Porous silicon particles and a method for producing silicon particles

Country Status (2)

Country Link
CN (1) CN107848809B (zh)
WO (1) WO2017214882A1 (zh)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108715451A (zh) * 2018-06-15 2018-10-30 辽宁科技大学 一种避免副产物产生的镁热还原制备纯硅材料方法
US10246337B2 (en) * 2017-02-17 2019-04-02 Battelle Memorial Institute Safe and low temperature thermite reaction systems and method to form porous silicon
CN111900369A (zh) * 2020-07-24 2020-11-06 陕西煤业化工技术研究院有限责任公司 一种预锂化氧化亚硅/碳复合材料及制备方法和应用
CN112151791A (zh) * 2020-09-08 2020-12-29 北大先行泰安科技产业有限公司 一种锂平衡的钴酸锂混合材料及其制备、检测方法

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109659529A (zh) * 2018-12-17 2019-04-19 潍坊汇成新材料科技有限公司 一种硅碳负极材料的制备工艺
CN109873150A (zh) * 2019-03-14 2019-06-11 西北师范大学 以坡缕石为原料制备纳米硅复合材料的方法
TWI723730B (zh) * 2020-01-10 2021-04-01 國立臺灣大學 製造多孔矽顆粒之方法及執行該方法之製造設備
WO2021165102A1 (en) * 2020-02-21 2021-08-26 Umicore A powder for use in the negative electrode of a battery, a method for preparing such a powder and a battery comprising such a powder
CN111446432A (zh) * 2020-04-20 2020-07-24 上海交通大学 一种用于锂离子电池的纳米硅/碳复合负极材料的制备方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102259858A (zh) * 2011-06-07 2011-11-30 同济大学 一种镁热还原制备多孔硅的方法
CN102916167A (zh) * 2011-08-04 2013-02-06 上海交通大学 用作锂离子电池负极材料的介孔硅复合物及其制备方法
WO2013078645A1 (en) * 2011-11-30 2013-06-06 Shanghai Jiao Tong University Mesoporous silicon/carbon composite for use as lithium ion battery anode material and process of preparing the same
US20140377653A1 (en) * 2013-06-21 2014-12-25 Unist Academy-Industry Research Corporation Porous silicon based negative electrode active material, method for manufacturing the same, and rechargeable lithium battery including the same
WO2016201611A1 (en) * 2015-06-15 2016-12-22 Robert Bosch Gmbh Porous silicon particles and a method for producing silicon particles

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011060023A2 (en) * 2009-11-11 2011-05-19 Amprius Inc. Preloading lithium ion cell components with lithium
US20140346618A1 (en) * 2013-05-23 2014-11-27 Nexeon Limited Surface treated silicon containing active materials for electrochemical cells

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102259858A (zh) * 2011-06-07 2011-11-30 同济大学 一种镁热还原制备多孔硅的方法
CN102916167A (zh) * 2011-08-04 2013-02-06 上海交通大学 用作锂离子电池负极材料的介孔硅复合物及其制备方法
WO2013078645A1 (en) * 2011-11-30 2013-06-06 Shanghai Jiao Tong University Mesoporous silicon/carbon composite for use as lithium ion battery anode material and process of preparing the same
US20140377653A1 (en) * 2013-06-21 2014-12-25 Unist Academy-Industry Research Corporation Porous silicon based negative electrode active material, method for manufacturing the same, and rechargeable lithium battery including the same
WO2016201611A1 (en) * 2015-06-15 2016-12-22 Robert Bosch Gmbh Porous silicon particles and a method for producing silicon particles

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10246337B2 (en) * 2017-02-17 2019-04-02 Battelle Memorial Institute Safe and low temperature thermite reaction systems and method to form porous silicon
CN108715451A (zh) * 2018-06-15 2018-10-30 辽宁科技大学 一种避免副产物产生的镁热还原制备纯硅材料方法
CN111900369A (zh) * 2020-07-24 2020-11-06 陕西煤业化工技术研究院有限责任公司 一种预锂化氧化亚硅/碳复合材料及制备方法和应用
CN112151791A (zh) * 2020-09-08 2020-12-29 北大先行泰安科技产业有限公司 一种锂平衡的钴酸锂混合材料及其制备、检测方法
CN112151791B (zh) * 2020-09-08 2022-04-01 泰丰先行(泰安)科技有限公司 一种锂平衡的钴酸锂混合材料及其制备、检测方法

Also Published As

Publication number Publication date
CN107848809A (zh) 2018-03-27
CN107848809B (zh) 2021-04-06

Similar Documents

Publication Publication Date Title
WO2017214882A1 (en) Porous silicon particles and a method for producing silicon particles
Das et al. Self-assembled MoS 2–carbon nanostructures: influence of nanostructuring and carbon on lithium battery performance
Rahman et al. A review on porous negative electrodes for high performance lithium-ion batteries
CN107528048B (zh) 硅碳复合物、制备该复合物的方法、包含该复合物的电极材料及电池
JP5716093B2 (ja) リチウムイオンキャパシタ用正極活物質およびその製造方法
KR101702980B1 (ko) 리튬 이차 전지용 음극 활물질 및 이를 포함하는 리튬 이차 전지
US20160156031A1 (en) Anode active material for lithium secondary battery and lithium secondary battery including the anode active material
KR101372145B1 (ko) 탄소나노튜브-올리빈형 리튬망간계인산화물 복합체의 제조 방법 및 이를 이용한 리튬이차전지
US9780357B2 (en) Silicon-based anode active material and secondary battery comprising the same
JP6104258B2 (ja) 電池用活物質
US20140099560A1 (en) Mesoporous metal oxide microsphere electrode compositions and their methods of making
JP2008130526A (ja) 電気化学素子用活物質、その製造方法、および電気化学素子
WO2016201611A1 (en) Porous silicon particles and a method for producing silicon particles
TW201444164A (zh) 正極活性物質－石墨烯複合體粒子及鋰離子電池用正極材料
WO2013146054A1 (ja) 非水電解質二次電池
Chen et al. Practical evaluation of prelithiation strategies for next‐generation lithium‐ion batteries
EP3422445B1 (en) Negative electrode material comprising silicon flakes and preparing method of silicon flakes
JP5760871B2 (ja) リチウムイオン二次電池用正極材料、リチウムイオン二次電池用正極部材、リチウムイオン二次電池、及びリチウムイオン二次電池用正極材料の製造方法
Lin et al. In situ electrochemical creation of cobalt oxide nanosheets with favorable performance as a high tap density anode material for lithium-ion batteries
JP5807730B1 (ja) 蓄電デバイスの電極用チタン酸リチウム粉末および活物質材料、並びにそれを用いた電極シートおよび蓄電デバイス
Okubo et al. Carbon coating of Si thin flakes and negative electrode properties in lithium-ion batteries
Han et al. Rapid microwave synthesis of Zn3 (OH) 2V2O7· 2H2O nanosheets for enhanced lithium storage performances
KR20150078068A (ko) 리튬 이차전지용 음극 활물질의 제조방법 및 리튬 이차전지
Nam et al. Electrode architecture of carbon-coated silicon nanowires through magnesiothermic reduction for lithium-ion batteries
KR102653877B1 (ko) 리튬 실리케이트 매트릭스를 포함하는 리튬 이차전지용 실리콘 복합 음극재, 이의 제조방법 및 이를 포함하는 리튬 이차전지용 음극

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16904999

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16904999

Country of ref document: EP

Kind code of ref document: A1