WO2023083147A1 - 一种负极活性材料及含有该负极活性材料的负极片和锂离子电池 - Google Patents

一种负极活性材料及含有该负极活性材料的负极片和锂离子电池 Download PDF

Info

Publication number
WO2023083147A1
WO2023083147A1 PCT/CN2022/130413 CN2022130413W WO2023083147A1 WO 2023083147 A1 WO2023083147 A1 WO 2023083147A1 CN 2022130413 W CN2022130413 W CN 2022130413W WO 2023083147 A1 WO2023083147 A1 WO 2023083147A1
Authority
WO
WIPO (PCT)
Prior art keywords
negative electrode
active material
electrode active
electrode sheet
graphite
Prior art date
Application number
PCT/CN2022/130413
Other languages
English (en)
French (fr)
Inventor
刘盼
刘春洋
陈若凡
李素丽
李俊义
徐延铭
Original Assignee
珠海冠宇电池股份有限公司
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 珠海冠宇电池股份有限公司 filed Critical 珠海冠宇电池股份有限公司
Publication of WO2023083147A1 publication Critical patent/WO2023083147A1/zh

Links

Images

Classifications

    • 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
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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 disclosure belongs to the technical field of lithium ion batteries, and more specifically, the disclosure relates to a negative electrode active material, a negative electrode sheet containing the negative electrode active material, and a lithium ion battery.
  • lithium-ion batteries have brought great convenience to people's lives. From mobile phones to portable electronic computers, from Bluetooth headsets to electric vehicles, these large and small devices are more or less inseparable from lithium-ion batteries.
  • people have put forward higher and higher requirements for the performance of lithium-ion batteries, such as fast charging, long battery life, low temperature performance, and long cycle, etc. These are the current lithium-ion batteries.
  • the volume requirements of portable mobile devices are getting higher and higher. Therefore, it has become a hot research topic in recent years to maximize the capacity of lithium-ion batteries in a certain space.
  • the present disclosure provides a negative electrode active material, the negative electrode active material is granular, and its particle diameters Dv10, Dv50 and Dv90 satisfy the following formula:
  • R represents a set of real numbers.
  • Dv10, Dv50 and Dv90 are measured by laser particle size method, which means that 10%, 50% and 90% of the particle size are in the measured size value.
  • Dv10 the particle size with cumulative particle distribution of 10%, that is, the volume content of particles smaller than this particle size accounts for 10% of all particles.
  • Dv50 The cumulative distribution of particles is 50% of the particle size, that is, the volume content of particles smaller than this particle size accounts for 50% of all particles. Also called median diameter or median particle diameter, this is a typical value indicating the particle size, which accurately divides the population into two equal parts, that is to say, 50% of the particles have a particle size exceeding this value, and 50 % of the particles have a particle size below this value. If the Dv50 of a sample is 5 ⁇ m, it means that among the particles of all particle sizes that make up the sample, the particles larger than 5 ⁇ m account for 50%, and the particles smaller than 5 ⁇ m also account for 50%.
  • Dv90 The cumulative distribution of particles is 90% of the particle size, that is, the volume content of particles smaller than this particle size accounts for 90% of all particles.
  • the particle size Dv50 of the negative electrode active material is 10 ⁇ m ⁇ 20 ⁇ m.
  • the particle size Dv10 of the negative electrode active material is 5 ⁇ m ⁇ 10 ⁇ m.
  • the particle size Dv90 of the negative electrode active material is 20 ⁇ m ⁇ 40 ⁇ m.
  • the negative electrode active material is selected from graphite.
  • the interlayer distance d002 of the graphite is 0.33356 nm ⁇ 0.3359 nm.
  • the graphite is at least one selected from natural graphite, artificial graphite, and mesocarbon microsphere graphite, preferably artificial graphite.
  • the reversible capacity of the negative electrode active material is 350mAh/g ⁇ 365mAh/g.
  • the "reversible capacity" is the first discharge specific capacity in the half-cell performance test.
  • the present disclosure also provides a negative electrode sheet, which includes the above-mentioned negative electrode active material.
  • the negative electrode sheet includes a current collector and an active material layer located on at least one side of the current collector, and the active material layer includes the above-mentioned negative electrode active material.
  • the current collector is selected from at least one of copper foil, chromium foil, nickel foil or titanium foil.
  • a conductive agent and a binder are further included in the active material layer.
  • the binder is selected from polyacrylic acid, sodium polyacrylate, potassium polyacrylate, lithium polyacrylate, polyvinyl alcohol, carboxymethyl cellulose, sodium carboxymethyl cellulose, polyimide , polyamideimide, styrene-butadiene rubber or polyvinylidene fluoride at least one.
  • the binder is a mixture of carboxymethyl cellulose and styrene-butadiene rubber.
  • the conductive agent is selected from at least one of acetylene black, conductive carbon black, single-walled carbon nanotubes, multi-walled carbon nanotubes, or graphene.
  • the negative electrode active material, the conductive agent, and the binder are in a mass ratio of 97:0.5:2.5; wherein, the binder is carboxymethyl cellulose and styrene-butadiene A mixture of rubber, the mass ratio is 1.3:1.2.
  • the negative electrode sheet has a compacted density of 1.75 g/cm 3 to 1.95 g/cm 3 .
  • the compacted density was obtained by rolling under a pressure of 17 MPa.
  • the present disclosure also provides an application of the above-mentioned negative electrode active material or the above-mentioned negative electrode sheet in a lithium-ion battery.
  • the present disclosure also provides a lithium-ion battery, which includes the above-mentioned negative electrode active material or the above-mentioned negative electrode sheet.
  • the lithium ion battery has high energy density.
  • the particle size distribution and layer spacing of the negative electrode active material are optimally and accurately controlled, and the particle size matching is adjusted so that the small particles in the graphite are filled into the pores between the large particles to prepare the electrode sheet.
  • the inside of the electrode sheet is denser and the compaction density of the electrode sheet is improved; on the other hand, the small particles in the graphite act as a buffer inside the electrode sheet And the role of support, so that the large particles will not be crushed and deformed by overpressure during the rolling process.
  • the present disclosure obtains a negative electrode sheet with a higher compaction density by adjusting the particle size distribution of the negative electrode active material and controlling the interlayer distance, and applying it to a lithium ion battery can further increase the energy density of the lithium ion battery.
  • Fig. 1 is the SEM picture of the negative electrode active material of embodiment 1;
  • Fig. 2 is the comparative schematic diagram before and after the rolling of the negative electrode sheet of embodiment 1 and comparative example 2, wherein, (1) is embodiment 1, (2) is comparative example 2;
  • Fig. 3 is a diagram of the capacity retention rate of the pouch battery of Example 1 at 25°C, 0.5C/0.5C charge-discharge cycle for 500 times.
  • test method and test conditions of the present disclosure are as follows:
  • Particle size Dv10, Dv50 and Dv90 test measured by Mastersize 3000 (Malvern 3000) by laser particle size method.
  • XRD test Measured by the equipment model ARL EQUINOX 5000, and obtained after correcting the diffraction peak position of the silicon standard sample (111) crystal plane.
  • the artificial graphite raw material is mixed with the petroleum pitch coating agent, and after heat treatment at 500°C to 600°C, the artificial graphite semi-finished material is obtained. Put the semi-finished product into the graphite crucible and carry out graphitization treatment.
  • the graphitization temperature is 2800°C ⁇ 3000°C. After the material is cooled down, the artificial graphite negative electrode material is obtained.
  • the particles are mixed and screened, and the particle size is adjusted and demagnetized to obtain an artificial graphite negative electrode active material with a certain particle size distribution.
  • Fig. 1 is the SEM picture of the negative pole active material in the embodiment 1, as can be seen from Fig. 1, negative pole active material comprises the smaller particle of particle diameter and the bigger particle of particle diameter, and particle composition is not uniform, and this particle The composition is conducive to the filling of small particle size graphite into the gap formed by large particle size graphite, which helps to increase the energy density of the pole piece.
  • Negative electrode sheet preparation the negative electrode active material and conductive carbon black, carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) are formulated into negative electrode slurry according to the mass ratio of 97%: 0.5%: 1.3%: 1.2%. The slurry is evenly coated on the 6 ⁇ m copper foil.
  • CMC carboxymethyl cellulose
  • SBR styrene-butadiene rubber
  • the above-mentioned positive electrode, negative electrode, diaphragm, and electrolyte are assembled into a soft-
  • Preparation of the working electrode at 25°C, mix the negative electrode active material with CMC, conductive carbon black, and SBR in pure water according to 92%: 1.5%: 1.5%: 5% (mass ratio), and prepare Form a slurry; apply the slurry evenly on the 8 ⁇ m copper foil, the coating surface density is about 8mg/cm 2 , and then put the copper foil in a vacuum drying oven at 80°C for 12 hours. Cut the dried pole piece into a disc with a diameter of 20mm to make a working electrode.
  • Half-cell performance test After the assembled half-cell was left to stand at 25°C for 24 hours, the electrochemical test was started. The electrochemical test was tested on an American Arbin BT2000 battery tester.
  • the test process is as follows: discharge at 0.05C to 5mV, stand still for 10min, discharge at 0.05C to 5mV, stand still for 10min, discharge at 0.05mA to 5mV, get the first lithium intercalation capacity of graphite, after standing for 10min, charge at 0.1C to 2.0V, the first cycle is completed, and the first delithiation capacity of graphite is obtained.
  • the first delithiation capacity is divided by the mass of the negative electrode active material to obtain the first discharge specific capacity of the material; the first delithiation capacity/the first lithium intercalation capacity is the first efficiency of the material.
  • the pouch batteries prepared in Examples 1-6 and Comparative Examples 1-3 were charged and discharged with an ArbinBT2000 battery tester, and the energy density and cycle capacity retention rate of the full battery were tested according to the following methods:
  • K is lower than 2.5, the particle size distribution of the negative electrode active material is too concentrated, and when K is higher than 3.5, the particle size distribution of the negative electrode active material is too dispersed, and the compacted density of the negative electrode sheet cannot meet the requirements of rolling.
  • Such graphite particles have a high compaction density in the negative electrode sheet.
  • the size of the particles can be matched, so that the small particles can be filled into the pores between the large particles, and the compaction density of the negative electrode sheet can be improved.
  • the support and buffering effect of the small particles also prevent the large particles from being squeezed and deformed, so the obtained lithium-ion battery has a higher energy density.
  • (1) and (2) are schematic diagrams of comparison between Example 1 and Comparative Example 2 before and after rolling.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

本公开提供一种负极活性材料及含有该负极活性材料的负极片和锂离子电池。本公开所述负极活性材料呈颗粒状，其粒径Dv10、Dv50、Dv90满足如下公式：(Dv90) 2＝K[(Dv10) 2+(Dv50) 2]，其中K∈[2.5，3.5]且K∈R。本公开通过调节负极活性材料粒径分布、且进一步控制层间距，得到一种压实密度较高的负极片，将其应用在锂离子电池中，可进一步提升锂离子电池的能量密度。

Description

一种负极活性材料及含有该负极活性材料的负极片和锂离子电池 技术领域
本公开属于锂离子电池技术领域，更具体的说，本公开涉及一种负极活性材料及含有该负极活性材料的负极片和锂离子电池。
背景技术
锂离子电池的问世给人们的生活带来了巨大的便利，从移动电话到便携式电子计算机，从蓝牙耳机到电动汽车，这些大大小小的装置或多或少都离不开锂离子电池。然而，随着社会的发展，科技的进步，人们对锂离子电池的性能提出了越来越高的要求，快速充电，超长续航，低温性能，超长循环等，这些都是锂电池目前面对的挑战。随着数字化智能化时代的到来，便携式移动设备体积要求越来越高，因此，在一定空间内能够尽可能多的发挥锂离子电池的容量成为近年来人们研究的热门课题。
发明内容
本公开提供一种负极活性材料，所述负极活性材料呈颗粒状，其粒径Dv10、Dv50和Dv90满足如下公式：
(Dv90) 2＝K[(Dv10) 2+(Dv50) 2]，
其中K∈[2.5，3.5]且K∈R。
本公开中，R表示实数集。
本公开中，Dv10、Dv50和Dv90由激光粒度法测定，代表的含义是10％、50％和90％的颗粒尺寸在所测得的尺寸值。
具体的，Dv10：颗粒累积分布为10％的粒径，即小于此粒径的颗粒体积含量占全部颗粒的10％。
Dv50：颗粒累积分布为50％的粒径，即小于此粒径的颗粒体积含量占全部颗粒的50％。也叫中位径或中值粒径，这是一个表示粒度大小的典型值，该值准确地将总体划分为二等份，也就是说有50％的颗粒的粒径超过此值，有50％的颗粒的粒径低于此值。如果一个样品的Dv50＝5μm，说明在组成该样品的所有粒径的颗粒中，大于5μm的颗粒占50％，小于5μm的颗粒也占50％。
Dv90：颗粒累积分布为90％的粒径，即小于此粒径的颗粒体积含量占全部颗粒的90％。
根据本公开的实施方案，所述负极活性材料的粒径Dv50＝10μm～20μm。
根据本公开的实施方案，所述负极活性材料的粒径Dv10＝5μm～10μm。
根据本公开的实施方案，所述负极活性材料的粒径Dv90＝20μm～40μm。
根据本公开的实施方案，所述负极活性材料选自石墨。
根据本公开的实施方案，所述石墨的层间距d002＝0.33356nm～0.3359nm。
根据本公开的实施方案，所述石墨选自天然石墨、人造石墨、中间相炭微球石墨中的至少一种，优选为人造石墨。
根据本公开的实施方案，所述负极活性材料的可逆容量为350mAh/g～365mAh/g。
在本公开中，所述“可逆容量”为半电池性能测试中首次放电比容量。
本公开还提供一种负极片，所述负极片包括上述的负极活性材料。
根据本公开的实施方案，所述负极片包括集流体和位于所述集流体至少一侧的活性物质层，所述活性物质层中包括上述的负极活性材料。
根据本公开的实施方案，所述集流体选自铜箔、铬箔、镍箔或钛箔中的至少一种。
根据本公开的实施方案，所述活性物质层中还包括导电剂和粘结剂。
根据本公开的实施方案，所述粘结剂选自聚丙烯酸、聚丙烯酸钠、聚丙烯酸钾、聚丙烯酸锂、聚乙烯醇、羧甲基纤维素、羧甲基纤维素钠、聚酰亚胺、聚酰胺酰亚胺、丁苯橡胶或聚偏氟乙烯中的至少一种。示例性地，所述粘结剂为羧甲基纤维素和丁苯橡胶的混合物。
根据本公开的实施方案，所述导电剂选自乙炔黑、导电炭黑、单壁碳纳米管、多壁碳纳米管或石墨烯中的至少一种。
根据本公开示例性的方案，所述负极片中，负极活性材料、导电剂和粘结剂按照质量比为97：0.5：2.5；其中，所述粘结剂为羧甲基纤维素和丁苯橡胶的混合物，质量比为1.3:1.2。
根据本公开的实施方案，所述负极片的压实密度为1.75g/cm 3～1.95g/cm 3。具体地，在17MPa压力下辊压得到所述压实密度。
本公开还提供上述负极活性材料或上述负极片在锂离子电池中的应用。
本公开还提供一种锂离子电池，所述锂离子电池包括上述负极活性材料或上述负极片。
根据本公开，所述锂离子电池具有高能量密度。
本公开的有益效果：
本公开通过优选和精确控制负极活性材料的粒径分布和层间距，通过大小颗粒搭配调节，使石墨中的小颗粒填充到大颗粒之间的孔隙中制得电极片。在电极片辊压过程中，一方面由于石墨中的小颗粒的填充，使得极片内部更加密实，提 升了极片的压实密度；另一方面石墨中的小颗粒在电极片内部起到了缓冲和支撑的作用，使得辊压过程中大颗粒不会被过压导致破碎变形。因此，本公开通过调节负极活性材料粒径分布和控制层间距，得到一种压实密度较高的负极片，将其应用在锂离子电池中，可进一步提升锂离子电池的能量密度。
附图说明
图1是实施例1的负极活性材料的SEM图；
图2是实施例1与对比例2的负极片辊压前后的对比示意图，其中，(1)是实施例1，(2)是对比例2；
图3是实施例1的软包电池在25℃，0.5C/0.5C充放循环500次的容量保持率图。
具体实施方式
下文将结合具体实施例对本公开的技术方案做更进一步的详细说明。应当理解，下列实施例仅为示例性地说明和解释本公开，而不应被解释为对本公开保护范围的限制。凡基于本公开上述内容所实现的技术均涵盖在本公开旨在保护的范围内。
除非另有说明，以下实施例中使用的原料和试剂均为市售商品，或者可以通过已知方法制备。
本公开的测试方法和测试条件如下：
1、颗粒粒径Dv10、Dv50和Dv90测试：采用激光粒度法，由Mastersize 3000(马尔文3000)测得。
2、XRD测试：由设备型号为ARL EQUINOX 5000测得，并根据硅标准样品(111)晶面衍射峰位置修正后得到。
实施例1
(1)负极活性材料制备：将石油针状焦进行低温煅烧(600℃～800℃)得到煅后焦，将煅后焦粉碎整形，控制粒径Dv10、Dv50、Dv90的大小范围，得到具有一定粒径分布的人造石墨原料。将人造石墨原料与石油沥青包覆剂进行混合，经过500℃～600℃热处理，得到人造石墨半成品物料。将半成品装入石 墨坩埚中，进行石墨化处理，石墨化温度为2800℃～3000℃，物料降温后得到人造石墨负极材料。最后，将物料进行混合筛分，粒径调整和除磁后得到具有一定粒径分布的人造石墨负极活性材料。所得人造石墨的颗粒粒径为：Dv10＝6.1μm，Dv50＝15.1μm，Dv90＝28.5μm；XRD测得：石墨的层间距为d002＝0.3357nm。
图1是实施例1中的负极活性材料的SEM图，从图1中可以看出，负极活性材料包括粒径较小的颗粒和粒径较大的颗粒，颗粒组成并不均一，这种颗粒组成有利于小粒径石墨填充到大粒径石墨形成的空隙中，有助于提升极片能量密度。
(2)负极片制备：将负极活性材料与导电炭黑、羧甲基纤维素(CMC)和丁苯橡胶(SBR)按照质量比为97％：0.5％：1.3％：1.2％配制成负极浆料，将该浆料均匀涂覆在6μm后的铜箔上。
(3)软包电池组装：将步骤2制备的负极片作为负极，正极的制作方法如下：正极活性物质为钴酸锂(LCO)，浆料配方为LCO：导电炭黑：聚偏氟乙烯(PVDF)＝97.5％：1.0％：1.5％(质量比)；电解液为：1mol/L LiPF 6、其溶剂为EC/DMC/EMC体积比为1：1：1所构成的溶液；所用隔膜为聚乙烯隔膜；正极设计容量为185mAh/g；负极设计容量根据半电池容量测试结果进行设计，其中，CB值为1.07，负极片压实密度为1.80g/cm 3，面密度为12.0mg/cm 2。将上述正极、负极、隔膜、电解液组装成软包全电池。
实施例2
(1)负极活性材料制备：参照实施例1中负极活性材料的制备方法，得到负极石墨活性材料，其粒径为：Dv10＝9.5μm，Dv50＝19.1μm，Dv90＝37.6μm；XRD结果为：石墨的层间距为d002＝0.3356nm。
(2)负极片制备：负极片制备与实施例1相同。
(3)软包电池组装：同实施例1，其中，负极片压实密度为1.85g/cm 3。
实施例3
(1)负极活性材料制备：参照实施例1中负极活性材料的制备方法，得到负极石墨活性材料，其粒径为：Dv10＝5.2μm，Dv50＝12.3μm，Dv90＝23.6μm；XRD结果为：石墨的层间距为d002＝0.3359nm。
(2)负极片制备：负极片制备与实施例1相同。
(3)软包电池组装：同实施例1，其中，负极片压实密度为1.76g/cm 3。
实施例4
(1)负极活性材料制备：参照实施例1中负极活性材料的制备方法，得到负极石墨活性材料，其粒径为：Dv10＝6.7μm，Dv50＝15.0μm，Dv90＝27.2μm；XRD结果为：石墨的层间距为d002＝0.3358nm。
(2)负极片制备：负极片制备与实施例1相同。
(3)软包电池组装：同实施例1，其中，负极片压实密度为1.78g/cm 3。
实施例5
(1)负极活性材料制备：参照实施例1中负极活性材料的制备方法，得到负极石墨活性材料，其粒径为：Dv10＝8.0μm，Dv50＝16.1μm，Dv90＝28.6μm，XRD结果为：石墨的层间距为d002＝0.3356nm。
(2)负极片制备：负极片制备与实施例1相同。
(3)软包电池组装：同实施例1，其中，负极片压实密度为1.82g/cm 3。
实施例6
(1)负极活性材料制备：参照实施例1中负极活性材料的制备方法，得到负极石墨活性材料，其粒径为：Dv10＝8.4μm，Dv50＝17.3μm，Dv90＝35.4μm；XRD结果为：石墨的层间距为d002＝0.3356nm。
(2)负极片制备：负极片制备与实施例1相同。
(3)软包电池组装：同实施例1，其中，负极片压实密度为1.83g/cm 3。
对比例1
(1)负极活性材料制备：参照实施例1中负极活性材料的制备方法，得到负极石墨活性材料，其粒径为：Dv10＝5.2μm，Dv50＝9.3μm，Dv90＝29.5μm； XRD结果为：石墨的层间距为d002＝0.3361nm。
(2)负极片制备：负极片制备与实施例1相同。
(3)软包电池组装：同实施例1，其中，负极片压实密度为1.60g/cm 3。
对比例2
(1)负极活性材料制备：参照实施例1中负极材料的制备方法，得到负极石墨活性材料，其粒径为：Dv10＝10.3μm，Dv50＝18.6μm，Dv90＝29.5μm；XRD结果为：石墨的层间距为d002＝0.3356nm。
(2)负极片制备：与实施例1相同。
(3)软包电池组装：同实施例1，其中，负极片压实密度为1.84g/cm 3。
对比例3
(1)负极活性材料制备：参照实施例1中负极活性材料的制备方法，得到负极石墨活性材料，其粒径为：Dv10＝5.4μm，Dv50＝17.1μm，Dv90＝35.3μm；XRD结果为：石墨的层间距为d002＝0.3359nm。
(2)负极片制备：负极片制备与实施例1相同。
(3)软包电池组装：同实施例1，其中，负极片压实密度为1.62g/cm 3。
测试例1
分别取实施例1-6和对比例1-3所制备的负极活性材料进行如下半电池性能测试：
1、工作电极的制备：在25℃条件下，将负极活性材料分别与CMC、导电炭黑、SBR按照92％：1.5％：1.5％：5％(质量比)在纯水中混合均匀，配制成浆料；把浆料均匀涂在8μm铜箔上，涂布面密度约为8mg/cm 2，然后把铜箔放入真空干燥箱中80℃烘干12h。将烘干后的极片裁成直径为20mm的圆片，制成工作电极。
2、半电池的装配：在25℃条件下，以金属锂片作为对电极，聚乙烯隔膜为电池隔膜，1mol/L的LiPF 6/EC:DEC(体积比为1:1)溶液为电解液，与上述工作电极在Ar环境下的手套箱中组装成CR2430型纽扣电池，其中，工作电极 的压实密度为1.50g/cm 3，单面密度为8mg/cm 2。
3、半电池性能测试：将组装好的半电池在25℃条件下静置24h后开始电化学测试，电化学测试在美国ArbinBT2000型电池测试仪上测试。
4、容量和首效测试：
(1)测试过程如下：0.05C放电至5mV，静置10min，0.05C放电至5mV，静置10min，0.05mA放电至5mV，得到石墨首次嵌锂容量，静置10min后，以0.1C充电到2.0V，完成首次循环，得到石墨首次脱锂容量。
(2)首次放电比容量和首次效率结果计算：首次脱锂容量除以负极活性材料的质量，得到材料的首次放电比容量；首次脱锂容量/首次嵌锂容量即为材料的首次效率。
实施例与对比例的测试结果见表1。
测试例2
将实施例1-6和对比例1-3所制备的软包电池使用ArbinBT2000型电池测试仪进行电池充放电测试，按照如下方法测试得到全电池能量密度和循环容量保持率：
1、全电池能量密度：环境温度25℃，对软包电池进行放电测试，电流密度为0.2C，放电电压范围为4.45～3.0V，得到软包电池的放电容量C(Ah)，根据充放电曲线，得到电池放电中压U(V)，未经充放电测试的新鲜电池的体积记为V(L)，电池的能量密度为E(Wh/L)，E＝C*U/V；
2、循环容量保持率：环境温度25℃，对软包电池进行充放电测试，充放电电流密度均为0.5C，充放电电压范围为4.45～3.0V，电池经过一次放电和一次充电为一个循环周期，循环500次后，计算电池的容量保持率：容量保持率＝第500次放电容量/电池初始容量*100％，电池充放电程序设置如下：
1.静置10min；
2.0.5C恒流放电至3.0V；
3.静置30min；
4.0.5C恒流充电至4.45V，恒压充电至电流密度为0.05C；
重复1～4步程序至500次。
如图3所示，为实施例1的软包电池在25℃，0.5C/0.5C充放循环500次的容量保持率。
实施例与对比例的测试结果见表1。
表1实施例与对比例的测试结果
Figure PCTCN2022130413-appb-000001
从表1中的测试结果可以看出，实施例1～6中负极活性材料具有如下特征：其粒径分布满足如下关系式：(Dv90) 2＝K[(Dv10) 2+(Dv50) 2]，其中K∈[2.5，3.5]且K∈R，Dv50＝10μm～20μm；石墨层间距d002在0.3356nm～0.3359nm之间。发明人认为，当K低于2.5时，负极活性材料的粒径分布过于集中，当K高于3.5时，负极活性材料的粒径分布过于分散，负极片的压实密度均不能满足要求辊压条件，从而影响电池的能量密度。这样的石墨颗粒在负极片中具有较高的压实密度，通过严格控制石墨粒径，实现大小颗粒搭配，从而使小颗粒填充到大颗粒之间的孔隙中，负极片压实密度得以提高，同时，极片经过辊压后，小颗粒的支撑和缓冲作用也使得大颗粒不被挤压变形，因此得到的锂离子电池具有较高的能量密度。而对比例2中，K＝1.92＜2.5，因此负极活性材料粒径分布过于集中，辊压使得颗粒变形严重，得到的锂离子电池无法进行充放电。如图2中，(1)和(2)分别是实施例1与对比例2辊压前后的对比示意图。
以上对本公开示例性的实施方式进行了说明。但是，本公开的保护范围不拘囿于上述实施方式。本领域技术人员在本公开的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本公开的保护范围之内。

Claims (15)

  1. 一种负极活性材料，其特征在于，
    所述负极活性材料呈颗粒状，其粒径Dv10、Dv50、Dv90满足如下公式：
    (Dv90) 2＝K[(Dv10) 2+(Dv50) 2]，
    其中K∈[2.5，3.5]且K∈R。
  2. 根据权利要求1所述的负极活性材料，其特征在于，所述负极活性材料的粒径Dv50＝10μm～20μm；
    和/或，所述负极活性材料的粒径Dv10＝5μm～10μm；
    和/或，所述负极活性材料的粒径Dv90＝20μm～40μm。
  3. 根据权利要求1或2所述的负极活性材料，其特征在于，所述负极活性材料选自石墨。
  4. 根据权利要求3所述的负极活性材料，其特征在于，所述石墨选自天然石墨、人造石墨、中间相炭微球石墨中的至少一种；优选为人造石墨。
  5. 根据权利要求3所述的负极活性材料，其特征在于，所述石墨的层间距d002＝0.33356nm～0.3359nm。
  6. 根据权利要求1-5任一项所述的负极活性材料，其特征在于，所述负极活性材料的可逆容量为350mAh/g～365mAh/g。
  7. 一种负极片，其特征在于，所述负极片包括权利要求1-6任一项所述的负极活性材料。
  8. 根据权利要求7所述的负极片，其特征在于，所述负极片包括集流体和位于所述集流体至少一侧的活性物质层，所述活性物质层中包括权利要求1-6任一项所述的负极活性材料。
  9. 根据权利要求7或8所述的负极片，其特征在于，所述活性物质层中还包括导电剂和粘结剂。
  10. 根据权利要求9所述的负极片，其特征在于，所述粘结剂选自聚丙烯酸、聚丙烯酸钠、聚丙烯酸钾、聚丙烯酸锂、聚乙烯醇、羧甲基纤维素、羧甲基纤维素钠、聚酰亚胺、聚酰胺酰亚胺、丁苯橡胶或聚偏氟乙烯中的至少一种。
  11. 根据权利要求9所述的负极片，其特征在于，所述导电剂选自乙炔黑、导电炭黑、单壁碳纳米管、多壁碳纳米管或石墨烯中的至少一种。
  12. 根据权利要求9-11任一项所述的负极片，其特征在于，所述负极活性材料、所述导电剂和所述粘结剂的质量比为97：0.5：2.5；
    优选地，所述粘结剂为羧甲基纤维素和丁苯橡胶的混合物，所述羧甲基纤维素和所述丁苯橡胶的质量比为1.3:1.2。
  13. 根据权利要求7-12任一项所述的负极片，其特征在于，所述负极片的压实密度为1.80g/cm 3～1.95g/cm 3。
  14. 根据权利要求7-13任一项所述的负极片，其特征在于，所述集流体选自铜箔、铬箔、镍箔或钛箔中的至少一种。
  15. 一种锂离子电池，其特征在于，所述锂离子电池包括权利要求1-6任一项所述的负极活性材料，和/或，权利要求7-14任一项所述的负极片。
PCT/CN2022/130413 2021-11-11 2022-11-07 一种负极活性材料及含有该负极活性材料的负极片和锂离子电池 WO2023083147A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202111335024.9 2021-11-11
CN202111335024 2021-11-11

Publications (1)

Publication Number Publication Date
WO2023083147A1 true WO2023083147A1 (zh) 2023-05-19

Family

ID=80792782

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/130413 WO2023083147A1 (zh) 2021-11-11 2022-11-07 一种负极活性材料及含有该负极活性材料的负极片和锂离子电池

Country Status (2)

Country Link
CN (1) CN114256452A (zh)
WO (1) WO2023083147A1 (zh)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114256452A (zh) * 2021-11-11 2022-03-29 珠海冠宇电池股份有限公司 一种负极活性材料及含有该负极活性材料的负极片和锂离子电池
KR20230150873A (ko) * 2022-04-21 2023-10-31 비티알 뉴 머티리얼 그룹 코., 엘티디. 음극 재료, 이의 제조 방법 및 리튬 이온 배터리
CN116646473A (zh) * 2023-07-26 2023-08-25 深圳海辰储能控制技术有限公司 负极极片、二次电池和用电设备

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007141677A (ja) * 2005-11-18 2007-06-07 Showa Denko Kk 複合黒鉛及びそれを用いたリチウム二次電池
CN104779413A (zh) * 2015-04-09 2015-07-15 深圳市美拜电子有限公司 一种锂离子电池
JP2015155366A (ja) * 2014-02-20 2015-08-27 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 天然黒鉛のボールミリングによる機械的改質方法及び改質天然黒鉛系負極材料
CN110120497A (zh) * 2018-02-07 2019-08-13 宁德新能源科技有限公司 一种活性材料和锂离子电池
KR20200074552A (ko) * 2018-12-17 2020-06-25 주식회사 엘지화학 이차전지용 음극 활물질, 이를 포함하는 음극 및 이의 제조방법
CN114256452A (zh) * 2021-11-11 2022-03-29 珠海冠宇电池股份有限公司 一种负极活性材料及含有该负极活性材料的负极片和锂离子电池

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009026514A (ja) * 2007-07-18 2009-02-05 Panasonic Corp 非水電解質二次電池
JP2011134572A (ja) * 2009-12-24 2011-07-07 Hitachi Powdered Metals Co Ltd 非水二次電池用負極活物質およびこれを用いた非水二次電池
JP6201425B2 (ja) * 2013-05-23 2017-09-27 日立化成株式会社 リチウムイオン二次電池用負極材、リチウムイオン二次電池用負極及びリチウムイオン二次電池
CN103441305B (zh) * 2013-08-27 2016-09-21 深圳市贝特瑞新能源材料股份有限公司 一种动力与储能锂离子电池及其制备方法
JP2015187972A (ja) * 2014-03-13 2015-10-29 新日鉄住金化学株式会社 リチウムイオン二次電池用負極活物質及びそれを用いたリチウムイオン二次電池負極並びにリチウムイオン二次電池
WO2016121585A1 (ja) * 2015-01-29 2016-08-04 Ｎｅｃエナジーデバイス株式会社 リチウムイオン二次電池用負極及びリチウムイオン二次電池
KR102449847B1 (ko) * 2015-10-27 2022-09-29 삼성에스디아이 주식회사 리튬 이차 전지용 음극 활물질 및 이를 포함하는 리튬 이차 전지
JP7107888B2 (ja) * 2019-05-10 2022-07-27 本田技研工業株式会社 固体電池用負極活物質、当該活物質を用いた負極および固体電池
CN111533120A (zh) * 2020-05-08 2020-08-14 珠海冠宇电池股份有限公司 一种负极活性材料及具有改善的高电压快充循环性能的锂离子电池

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007141677A (ja) * 2005-11-18 2007-06-07 Showa Denko Kk 複合黒鉛及びそれを用いたリチウム二次電池
JP2015155366A (ja) * 2014-02-20 2015-08-27 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 天然黒鉛のボールミリングによる機械的改質方法及び改質天然黒鉛系負極材料
CN104779413A (zh) * 2015-04-09 2015-07-15 深圳市美拜电子有限公司 一种锂离子电池
CN110120497A (zh) * 2018-02-07 2019-08-13 宁德新能源科技有限公司 一种活性材料和锂离子电池
KR20200074552A (ko) * 2018-12-17 2020-06-25 주식회사 엘지화학 이차전지용 음극 활물질, 이를 포함하는 음극 및 이의 제조방법
CN114256452A (zh) * 2021-11-11 2022-03-29 珠海冠宇电池股份有限公司 一种负极活性材料及含有该负极活性材料的负极片和锂离子电池

Also Published As

Publication number Publication date
CN114256452A (zh) 2022-03-29

Similar Documents

Publication Publication Date Title
WO2020177623A1 (zh) 负极片、二次电池及其装置
WO2023083147A1 (zh) 一种负极活性材料及含有该负极活性材料的负极片和锂离子电池
WO2016008455A2 (zh) 一种多元复合负极材料、其制备方法及包含其的锂离子电池
WO2021108983A1 (zh) 二次电池、装置、人造石墨及制备方法
WO2021108982A1 (zh) 人造石墨、二次电池、制备方法及装置
CN110660984B (zh) 一种纳米硅碳复合材料及其制备方法和应用
WO2022121281A1 (zh) 一种自填充包覆硅基复合材料、其制备方法及其应用
WO2021108981A1 (zh) 二次电池、装置、人造石墨及制备方法
WO2022052994A1 (zh) 石墨负极材料、负极和锂离子电池及其制备方法
US9023521B2 (en) Nonaqueous electrolyte secondary battery
WO2016202164A1 (zh) 一种炭/石墨/锡复合负极材料的制备方法
CN112072069B (zh) 一种正极极片及包括该正极极片的锂离子电池
CN112072071B (zh) 一种正极极片及包括该正极极片的锂离子电池
WO2022205152A1 (zh) 一种负极极片、包含该负极极片的电化学装置和电子装置
CN114447305A (zh) 一种多元碳基快充负极复合材料及其制备方法
WO2018059180A1 (zh) 一种高功率高能量化学电源及其制备方法
WO2023124025A1 (zh) 一种石墨复合负极材料及其制备方法和应用
WO2023169597A1 (zh) 一种硅基复合材料及其制备方法、锂电池的负极材料及其制备方法、锂电池
CN114597326A (zh) 一种负极活性材料及含有该负极活性材料的负极片和电池
WO2022121280A1 (zh) 一种类石榴结构硅基复合材料、其制备方法及其应用
CN112542572A (zh) 一种新型锂离子电池正极极片及其制备方法和用途
CN114122329A (zh) 一种负极片和包括该负极片的锂离子电池
WO2022077374A1 (zh) 负极活性材料、其制备方法、二次电池及包含二次电池的电池模块、电池包和装置
CA3181237A1 (en) Positive electrode of hybrid capacitor and manufacturing method therefor and use thereof
WO2023179146A1 (zh) 一种负极活性材料及含有该负极活性材料的负极片和电池

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: 22891941

Country of ref document: EP

Kind code of ref document: A1