WO2021189407A1

WO2021189407A1 - Negative electrode active material, and electrochemical device and electronic device using same

Info

Publication number: WO2021189407A1
Application number: PCT/CN2020/081609
Authority: WO
Inventors: 杜鹏; 谢远森; 陈茂华
Original assignee: 宁德新能源科技有限公司
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2021-09-30
Also published as: CN115191043A

Abstract

The present application relates to a negative electrode active material, and an electrochemical device and electronic device using same. Specifically, the present application provides a negative electrode active material, which comprises a negative electrode active substance and a protective layer on the surface of the negative electrode active substance, wherein according to flight time secondary ion mass spectrometry test, the protective layer comprises at least one of the following charged groups: C 2H 3 +, Si +, C 2H 5 +, C 3H 3 +, C 3H 5 +, C 3H 7 +, C 4H 5 +, C 4H 7 +, C 4H 9 +, C 5H 7 +, SiC 3H 9 +, C 6H 5 +, C 6H 7 +, C 6H 9 +, C 6H 11 +, C 6H 13 +, C 7H 7 +, C 7H 11 +, C 7H 13 +, C 8H 13 +, C 8H 11N 2 +, Si 2OC 5H 15 +, Si 3O 2C 5H 15 +, Si 3O 3C 5H 15 +, Si 3O 2C 7H 21 +, Si 4O 4C 7H 21 +, CH -, O -, CN -, C 3H 2 -, C 2HO -, C 4H -, C 2H 3O 2 -, SiO 2 -, PO 2 -, C 4H 7O -, C 3H 9N 2 -, SiO 2CH 3 -, PO 3 -, C 5H 7N -, Si 2O 3C 3H 9 -, C 14H 21O -, or Si 3O 4C 5H 15 -. The negative electrode active material of the present application improves the cycle performance and safety performance of an electrochemical device.

Description

负极活性材料及使用其的电化学装置和电子装置Anode active material and electrochemical device and electronic device using the same

技术领域Technical field

本申请涉及储能领域，具体涉及一种负极活性材料及使用其的电化学装置和电子装置。This application relates to the field of energy storage, in particular to a negative electrode active material and an electrochemical device and an electronic device using the same.

背景技术Background technique

电化学装置(例如，锂离子电池)由于具有环境友好、工作电压高、比容量大和循环寿命长等优点而被广泛应用，已成为当今世界最具发展潜力的新型绿色化学电源。小尺寸锂离子电池通常用作驱动便携式电子通讯设备(例如，便携式摄像机、移动电话或者笔记本电脑等)的电源，特别是高性能便携式设备的电源。近年来，具有高输出特性的中等尺寸和大尺寸锂例子电池被发展应用于电动汽车(EV)和大规模储能***(ESS)。随着锂离子电池的应用领域从消费类电子产品被扩展到混合动力和纯动力领域，其循环性能和安全性已成为亟待解决的关键技术问题。改进电极中的活性材料是解决上述问题的研究方向之一。Electrochemical devices (for example, lithium-ion batteries) are widely used due to their environmental friendliness, high working voltage, large specific capacity and long cycle life, and have become a new type of green chemical power source with the most development potential in the world today. Small-sized lithium-ion batteries are generally used as power sources for driving portable electronic communication devices (for example, camcorders, mobile phones, or notebook computers, etc.), especially high-performance portable devices. In recent years, medium-sized and large-sized lithium batteries with high output characteristics have been developed for use in electric vehicles (EV) and large-scale energy storage systems (ESS). As the application field of lithium-ion batteries is expanded from consumer electronics to hybrid and pure power fields, its cycle performance and safety have become key technical issues that need to be solved urgently. Improving the active material in the electrode is one of the research directions to solve the above problems.

有鉴于此，确有必要提供一种改进的负极活性材料及使用其的电化学装置和电子装置。In view of this, it is indeed necessary to provide an improved negative electrode active material and electrochemical devices and electronic devices using the same.

发明内容Summary of the invention

本申请通过提供一种负极活性材料及使用其的电化学装置和电子装置以试图在至少某种程度上解决至少一种存在于相关领域中的问题。The present application attempts to solve at least one problem existing in related fields at least to some extent by providing a negative electrode active material, an electrochemical device and an electronic device using the same.

根据本申请的一个方面，本申请提供了一种负极活性材料，其包括负极活性物质和在所述负极活性物质的表面的保护层，其中采用飞行时间二次离子质谱测试，所述保护层包括以下带电基团中的至少一种：C ₂H ₃ ⁺、Si ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₅ ⁺、C ₃H ₇ ⁺、C ₄H ₅ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、SiC ₃H ₉ ⁺、C ₆H ₅ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₂OC ₅H ₁₅ ⁺、Si ₃O ₂C ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺、Si ₃O ₂C ₇H ₂₁ ⁺、Si ₄O ₄C ₇H ₂₁ ⁺、CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、SiO ₂ ^-、PO ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、SiO ₂CH ₃ ^-、PO ₃ ^-、C ₅H ₇N ^-、Si ₂O ₃C ₃H ₉ ^-、C ₁₄H ₂₁O ^-或Si ₃O ₄C ₅H ₁₅ ^-。 According to one aspect of the present application, the present application provides a negative active material, which includes a negative active material and a protective layer on the surface of the negative active material, wherein a time-of-flight secondary ion mass spectrometry test is used, and the protective layer includes At least one of the following charged groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₅ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₂ OC ₅ H ₁₅ ⁺ , Si ₃ O ₂ C ₅ H _{^{_{_{15 +, Si 3 O 3 C}}}} 5 H 15 +, Si 3 O 2 C 7 H 21 +, Si 4 O 4 C 7 H 21 +, CH -, O -, CN -, C 3 H 2 -, C 2 ^{_{^{HO -, C 4 H -,}}} C 2 H 3 O 2 -, SiO 2 -, PO 2 -, C 4 H 7 O -, C 3 H 9 N 2 -, SiO 2 CH 3 -, PO 3 -, C _{_{^{_{5 H 7 N -, Si 2}}}} O 3 C 3 H 9 -, C 14 H 21 O - or _{_{_{_{Si 3 O 4 C 5 H 15}}}} -.

在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括带正电基团。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带正电基团中的至少一种：C ₂H ₃ ⁺、Si ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₇ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、SiC ₃H ₉ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₃O ₂C ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺或Si ₄O ₄C ₇H ₂₁ ⁺。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带正电基团中的至少一种：C ₂H ₃ ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₅ ⁺、C ₄H ₅ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、C ₆H ₅ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺或C ₈H ₁₁N ₂ ⁺。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带正电基团中的至少一种：C ₂H ₃ ⁺、Si ⁺、C ₃H ₅ ⁺、C ₃H ₇ ⁺、C ₄H ₅ ⁺、C ₄H ₉ ⁺、SiC ₃H ₉ ⁺、C ₆H ₅ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₂OC ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺或Si ₃O ₂C ₇H ₂₁ ⁺。 In some embodiments, time-of-flight secondary ion mass spectrometry is used, and the protective layer includes positively charged groups. In some embodiments, using time-of-flight secondary ion mass spectrometry, the protective layer includes at least one of the following positively charged groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₃ O ₂ C ₅ H ₁₅ ⁺ , Si ₃ O ₃ C ₅ H ₁₅ ⁺ or Si ₄ O ₄ C ₇ H ₂₁ ⁺ . In some embodiments, a time-of-flight secondary ion mass spectrometry test is used, and the protective layer includes at least one of the following positively charged groups: C ₂ H ₃ ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₅ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ or C ₈ H ₁₁ N ₂ ⁺ . In some embodiments, a time-of-flight secondary ion mass spectrometry test is used, and the protective layer includes at least one of the following positively charged groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₃ H ₅ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₉ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₂ OC ₅ H ₁₅ ⁺ , Si ₃ O ₃ C ₅ H ₁₅ ⁺ or Si ₃ O ₂ C ₇ H ₂₁ ⁺ .

在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括带负电基团。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带负电基团中的至少一种：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、SiO ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、C ₅H ₇N ^-、C ₁₄H ₂₁O ^-或Si ₃O ₄C ₅H ₁₅ ^-。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带负电基团中的至少一种：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、PO ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、PO ₃ ^-、C ₅H ₇N ^-或C ₁₄H ₂₁O ^-。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带负电基团中的至少一种：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₂H ₃O ₂ ^-、PO ₂ ^-、C ₄H ₇O ^-、SiO ₂CH ₃ ^-、C ₅H ₇N ^-、Si ₂O ₃C ₃H ₉ ^-、C ₁₄H ₂₁O ^-或Si ₃O ₄C ₅H ₁₅ ^-. In some embodiments, time-of-flight secondary ion mass spectrometry is used, and the protective layer includes negatively charged groups. In some embodiments, using time of flight secondary ion mass spectrometry, the protective layer comprising a negatively charged group at least one ^{^{of: CH -, O -, CN}} -, C 3 H 2 -, C 4 H - _{_{_{^{, C 2 H 3 O 2 -}}}} , SiO 2 -, C 4 H 7 O -, C 3 H 9 N 2 -, C 5 H 7 N -, C 14 H 21 O - or Si ₃ O ₄ C ₅ H ₁₅ ^- . In some embodiments, using time of flight secondary ion mass spectrometry, the protective layer comprising a negatively charged group at least one ^{^{of: CH -, O -, CN}} -, C 3 H 2 -, C 2 HO - _{^{_{, C 4 H -, C 2}}} H 3 O 2 -, PO 2 -, C 4 H 7 O -, C 3 H 9 N 2 -, PO 3 -, C 5 H 7 N - or C ₁₄ H ₂₁ O ^- . In some embodiments, using time of flight secondary ion mass spectrometry, the protective layer comprising a negatively charged group at least one ^{^{of: CH -, O -, CN}} -, C 3 H 2 -, C 2 HO - _{_{_{^{, C 2 H 3 O 2 -}}}} , PO 2 -, C 4 H 7 O -, SiO 2 CH 3 -, C 5 H 7 N -, Si 2 O 3 C 3 H 9 -, C 14 H 21 O - , or _{_{_{_{si 3 O 4 C 5 H 15}}}} -.

根据本申请的实施例，所述保护层的厚度为1nm至200nm。在一些实施例中，所述保护层的厚度为5nm至180nm。在一些实施例中，所述保护层的厚度为10nm至150nm。在一些实施例中，所述保护层的厚度为50nm至100nm。在一些实施例中，所述保护层的厚度为1nm、5nm、10nm、20nm、30nm、40nm、50nm、60nm、70nm、80nm、90nm、100nm、110nm、120nm、130nm、140nm、150nm、160nm、170nm、180nm、190nm或200nm。According to an embodiment of the present application, the thickness of the protective layer is 1 nm to 200 nm. In some embodiments, the thickness of the protective layer is 5 nm to 180 nm. In some embodiments, the thickness of the protective layer is 10 nm to 150 nm. In some embodiments, the thickness of the protective layer is 50 nm to 100 nm. In some embodiments, the thickness of the protective layer is 1nm, 5nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm , 180nm, 190nm or 200nm.

根据本申请的实施例，所述负极活性材料还包含金属元素，所述金属元素包含金、银、铂、锆、锌、镁、钙、钡、钒、铁或铝中的至少一种，基于所述负极活性材料的总重量，所述金属元素的含量小于0.1wt％。在一些实施例中，基于所述负极活性材料的总重量，所述金属元素的含量小于0.05wt％。基于所述负极活性材料的总重量，所述金属元素的含量为0.005wt％、0.01wt％、0.03wt％、0.05wt％、0.08wt％或0.1wt％。According to an embodiment of the present application, the negative active material further includes a metal element, and the metal element includes at least one of gold, silver, platinum, zirconium, zinc, magnesium, calcium, barium, vanadium, iron, or aluminum, based on The total weight of the negative active material, the content of the metal element is less than 0.1 wt%. In some embodiments, based on the total weight of the negative active material, the content of the metal element is less than 0.05 wt%. Based on the total weight of the negative active material, the content of the metal element is 0.005wt%, 0.01wt%, 0.03wt%, 0.05wt%, 0.08wt% or 0.1wt%.

根据本申请的实施例，所述负极活性材料进一步包含非金属元素，所述非金属元素包括硼、砷或硒中的至少一种，基于所述负极活性材料的总重量，所述非金属元素的含量为50ppm至200ppm。在一些实施例中，基于所述负极活性材料的总重量，所述非金属元素的含量为100ppm至150ppm。在一些实施例中，基于所述负极活性材料的总重量，所述非金属元素的含量为50ppm、60ppm、70ppm、80ppm、90ppm、100ppm、110ppm、120ppm、130ppm、140ppm、150ppm、160ppm、170ppm、180ppm、190ppm或200ppm。According to an embodiment of the present application, the negative electrode active material further includes a non-metal element, the non-metal element including at least one of boron, arsenic, or selenium, based on the total weight of the negative electrode active material, the non-metal element The content is 50ppm to 200ppm. In some embodiments, the content of the non-metallic elements is 100 ppm to 150 ppm based on the total weight of the negative active material. In some embodiments, based on the total weight of the negative active material, the content of the non-metal elements is 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140 ppm, 150 ppm, 160 ppm, 170 ppm, 180ppm, 190ppm or 200ppm.

根据本申请的实施例，所述负极活性材料包含孔道，所述孔道的内壁包含所述金属元素。According to an embodiment of the present application, the negative active material includes a pore, and the inner wall of the pore includes the metal element.

根据本申请的实施例，所述负极活性材料包含孔道，所述孔道的内壁包含所述非金属元素。According to an embodiment of the present application, the negative active material includes a pore, and the inner wall of the pore includes the non-metallic element.

根据本申请的实施例，所述负极活性材料包含磷元素，基于所述负极活性材料的总重量计，所述磷元素的含量不大于1wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述磷元素的含量不大于0.5wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述磷元素的含量不大于0.1wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述磷元素的含量为0.01wt％、0.03wt％、0.05wt％、0.08wt％、0.1wt％、0.3wt％、0.5wt％、0.8wt％或1wt％。According to an embodiment of the present application, the negative active material includes phosphorus element, and based on the total weight of the negative active material, the content of the phosphorus element is not more than 1 wt%. In some embodiments, based on the total weight of the negative active material, the content of the phosphorus element is not more than 0.5 wt%. In some embodiments, based on the total weight of the negative active material, the content of the phosphorus element is not more than 0.1 wt%. In some embodiments, based on the total weight of the negative active material, the content of the phosphorus element is 0.01wt%, 0.03wt%, 0.05wt%, 0.08wt%, 0.1wt%, 0.3wt%, 0.5wt %, 0.8wt% or 1wt%.

根据本申请的实施例，所述负极活性材料的中值粒径为5μm至20μm；所述负极活性材料的比表面积为0.7m ²/g至100m ²/g。在一些实施例中，所述负极活性材料的中值粒径为10μm至15μm。在一些实施例中，所述负极活性材料的中值粒径为5μm、8μm、10μm、12μm、15μm、18μm或20μm。在一些实施例中，所述负极活性材料的比表面积为1m ²/g至80m ²/g。在一些实施例中，所述负极活性材料的比表面积为10m ²/g至60m ²/g。在一些实施例中，所述负极活性材料的比表面积为30m ²/g至50m ²/g。在一些实施例中，所述负极活性材料的比表面积为0.7m ²/g、1m ²/g、5m ²/g、10m ²/g、20m ²/g、30m ²/g、40m ²/g、50m ²/g、60m ²/g、70m ²/g、80m ²/g、90m ²/g或100m ²/g。 According to an embodiment of the present application, the median particle size of the negative active material is 5 μm to 20 μm; the specific surface area of the negative active material is 0.7 m ² /g to 100 m ² /g. In some embodiments, the median particle diameter of the negative active material is 10 μm to 15 μm. In some embodiments, the median particle size of the negative active material is 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, or 20 μm. In some embodiments, the specific surface area of the negative active material is 1 m ² /g to 80 m ² /g. In some embodiments, the specific surface area of the negative active material is 10 m ² /g to 60 m ² /g. In some embodiments, the specific surface area of the negative active material is 30 m ² /g to 50 m ² /g. In some embodiments, the specific surface area of the negative active material is 0.7m ² /g, 1m ² /g, 5m ² /g, 10m ² /g, 20m ² /g, 30m ² /g, 40m ² /g , 50m ² /g, 60m ² /g, 70m ² /g, 80m ² /g, 90m ² /g or 100m ² /g.

根据本申请的另一个方面，本申请提供了一种电化学装置，其包括正极、电解液和负极，所述正极包括正极活性材料层和正极集流体，所述负极包括负极活性材料层和负极集流体，所述负极活性材料层包括根据本申请所述的负极活性材料。According to another aspect of the present application, the present application provides an electrochemical device, which includes a positive electrode, an electrolyte, and a negative electrode. The positive electrode includes a positive electrode active material layer and a positive electrode current collector, and the negative electrode includes a negative electrode active material layer and a negative electrode. The current collector, the negative active material layer includes the negative active material according to the present application.

根据本申请的实施例，所述负极活性材料层的孔隙率为15％至45％。在一些实施例中，所述负极活性材料层的孔隙率为20％至40％。在一些实施例中，所述负极活性材料层的孔隙率为25％至30％。在一些实施例中，所述负极活性材料层的孔隙率为15％、20％、25％、30％、35％、40％或45％。According to an embodiment of the present application, the porosity of the negative active material layer is 15% to 45%. In some embodiments, the porosity of the negative active material layer is 20% to 40%. In some embodiments, the porosity of the negative active material layer is 25% to 30%. In some embodiments, the porosity of the negative active material layer is 15%, 20%, 25%, 30%, 35%, 40%, or 45%.

根据本申请的实施例，所述负极活性材料层相对所述电解液的接触角为80°至96°。在一些实施例中，所述负极相对所述电解液的接触角为80°、81°、82°、83°、84°、85°、86°、87°、88°、89°、90°、91°、92°、93°、94°、95°或96°。According to an embodiment of the present application, the contact angle of the negative active material layer with respect to the electrolyte is 80° to 96°. In some embodiments, the contact angle of the negative electrode with respect to the electrolyte is 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, 90° , 91°, 92°, 93°, 94°, 95° or 96°.

根据本申请的又一个方面，本申请提供了一种电子装置，其包括根据本申请所述的电化学装置。According to another aspect of the present application, the present application provides an electronic device, which includes the electrochemical device according to the present application.

本申请的额外层面及优点将部分地在后续说明中描述、显示、或是经由本申请实施例的实施而阐释。The additional aspects and advantages of the present application will be partially described, shown, or explained through the implementation of the embodiments of the present application in the subsequent description.

附图说明Description of the drawings

在下文中将简要地说明为了描述本申请实施例或现有技术所必要的附图以便于描述本申请的实施例。显而易见地，下文描述中的附图仅只是本申请中的部分实施例。对本领域技术人员而言，在不需要创造性劳动的前提下，依然可以根据这些附图中所例示的结构来获得其他实施例的附图。Hereinafter, the drawings necessary to describe the embodiments of the present application or the prior art will be briefly described in order to describe the embodiments of the present application. Obviously, the drawings in the following description are only part of the embodiments in the present application. For those skilled in the art, without creative work, the drawings of other embodiments can still be obtained according to the structures illustrated in these drawings.

图1展示了根据本申请的一负极活性材料的飞行时间二次离子质谱(TOF-SIMS)图，其中根据TOF-SIMS测试，所述负极活性材料的保护层具有带正电基团。FIG. 1 shows a time-of-flight secondary ion mass spectrometry (TOF-SIMS) diagram of a negative active material according to the present application, wherein according to the TOF-SIMS test, the protective layer of the negative active material has positively charged groups.

图2展示了根据本申请的一负极活性材料的飞行时间二次离子质谱(TOF-SIMS)图，其中根据TOF-SIMS测试，所述负极活性材料的保护层具有带负电基团。FIG. 2 shows a time-of-flight secondary ion mass spectrometry (TOF-SIMS) diagram of a negative active material according to the present application. According to the TOF-SIMS test, the protective layer of the negative active material has negatively charged groups.

图3是根据本申请的负极活性材料相对电解液的接触角的示意图。Fig. 3 is a schematic diagram of the contact angle of the negative electrode active material with respect to the electrolyte according to the present application.

具体实施方式Detailed ways

本申请的实施例将会被详细的描示在下文中。在本申请说明书中，将相同或相似的组件以及具有相同或相似的功能的组件通过类似附图标记来表示。在此所描述的有关附图的实施例为说明性质的、图解性质的且用于提供对本申请的基本理解。本申请的实施例不应该被解释为对本申请的限制。The embodiments of this application will be described in detail below. In the specification of this application, the same or similar components and the components with the same or similar functions are denoted by similar reference numerals. The embodiments related to the drawings described herein are illustrative, diagrammatic, and used to provide a basic understanding of the present application. The embodiments of this application should not be construed as limitations on this application.

在具体实施方式及权利要求书中，由术语“中的至少一种”连接的项目的列表可意味着所列项目的任何组合。例如，如果列出项目A及B，那么短语“A及B中的至少一种”意味着仅A；仅B；或A及B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的至少一种”意味着仅A；或仅B；仅C；A及B(排除C)；A及C(排除B)；B及C(排除A)；或A、B及C的全部。项目A可包含单个元件或多个元件。项目B可包含单个元件或多个元件。项目C可包含单个元件或多个元件。In the detailed description and claims, a list of items connected by the term "at least one of" can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (exclude B); B and C (exclude A); or all of A, B, and C. Project A can contain a single element or multiple elements. Project B can contain a single element or multiple elements. Project C can contain a single element or multiple elements.

如本文中所使用，“孔道”指的是单个负极活性材料颗粒中的孔道或孔洞结构。As used herein, "pores" refer to pores or pore structures in a single negative electrode active material particle.

如本文中所使用，“孔隙”指的是负极活性材料的多个颗粒之间的空隙。As used herein, "pores" refer to voids between a plurality of particles of the negative active material.

为了提高电化学装置(例如，锂离子电池)的循环性能和安全性能，改善电极的活性材料是研发方向之一。石墨化负极活性材料的理论电化学容量的上限为372mAh/g，先前已知的石墨化负极活性材料的电化学容量难以突破该上限。硅负极活性材料具有高电化学容量，随着硅负极活性材料中掺杂材料含量的增加，电化学装置的能量密度可得到显著提升，但负极活性材料会发生明显的体积膨胀，反而会显著降低电化学装置的性能，尤其是会显著降低长循环中的容量保持率。In order to improve the cycle performance and safety performance of electrochemical devices (e.g., lithium ion batteries), improving the active materials of the electrodes is one of the research directions. The upper limit of the theoretical electrochemical capacity of the graphitized negative active material is 372 mAh/g, and it is difficult for the electrochemical capacity of the previously known graphitized negative active material to break through this upper limit. The silicon anode active material has a high electrochemical capacity. With the increase in the content of the doped material in the silicon anode active material, the energy density of the electrochemical device can be significantly improved, but the anode active material will undergo significant volume expansion, which will decrease significantly. The performance of the electrochemical device, in particular, will significantly reduce the capacity retention rate during long cycles.

为了解决这些问题，本申请提供了一种负极活性材料，其包括负极活性物质和在所述负极活性物质的表面的保护层，其中采用飞行时间二次离子质谱测试，所述保护层包括以下带电基团中的至少一种：C ₂H ₃ ⁺、Si ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₅ ⁺、C ₃H ₇ ⁺、C ₄H ₅ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、SiC ₃H ₉ ⁺、C ₆H ₅ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₂OC ₅H ₁₅ ⁺、Si ₃O ₂C ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺、Si ₃O ₂C ₇H ₂₁ ⁺、Si ₄O ₄C ₇H ₂₁ ⁺、CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、SiO ₂ ^-、PO ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、SiO ₂CH ₃ ^-、PO ₃ ^-、C ₅H ₇N ^-、Si ₂O ₃C ₃H ₉ ^-、C ₁₄H ₂₁O ^-或Si ₃O ₄C ₅H ₁₅ ^-。 In order to solve these problems, the present application provides a negative electrode active material, which includes a negative electrode active material and a protective layer on the surface of the negative electrode active material, wherein the time-of-flight secondary ion mass spectrometry test is adopted, and the protective layer includes the following charged At least one of the groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₅ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₂ OC ₅ H ₁₅ ⁺ , Si ₃ O ₂ C ₅ H ₁₅ ⁺ _{_{_{, Si 3 O 3 C 5 H}}} 15 +, Si 3 O 2 C 7 H 21 +, Si 4 O 4 C 7 H 21 +, CH -, O -, CN -, C 3 H 2 -, C 2 HO - _{^{_{, C 4 H -, C 2}}} H 3 O 2 -, SiO 2 -, PO 2 -, C 4 H 7 O -, C 3 H 9 N 2 -, SiO 2 CH 3 -, PO 3 -, C 5 H _{^{_{_{7 N -, Si 2 O 3}}}} C 3 H 9 -, C 14 H 21 O - or _{_{_{_{Si 3 O 4 C 5 H 15}}}} -.

在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括带正电基团。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带正电基团中的至少一种：C ₂H ₃ ⁺、Si ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₇ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、SiC ₃H ₉ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₃O ₂C ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺或Si ₄O ₄C ₇H ₂₁ ⁺。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带正电基团中的至少一种：C ₂H ₃ ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₅ ⁺、C ₄H ₅ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、C ₆H ₅ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺或C ₈H ₁₁N ₂ ⁺。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带正电基团中的至少一种：C ₂H ₃ ⁺、Si ⁺、C ₃H ₅ ⁺、C ₃H ₇ ⁺、C ₄H ₅ ⁺、C ₄H ₉ ⁺、SiC ₃H ₉ ⁺、C ₆H ₅ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₂OC ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺或Si ₃O ₂C ₇H ₂₁ ⁺。图1展示了根据本申请的一负极活性材料的飞行时间二次离子质谱(TOF-SIMS)图，其中采用TOF-SIMS测试，所述负极活性材料的保护层可激发出带正电离子。 In some embodiments, time-of-flight secondary ion mass spectrometry is used, and the protective layer includes positively charged groups. In some embodiments, using time-of-flight secondary ion mass spectrometry, the protective layer includes at least one of the following positively charged groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₃ O ₂ C ₅ H ₁₅ ⁺ , Si ₃ O ₃ C ₅ H ₁₅ ⁺ or Si ₄ O ₄ C ₇ H ₂₁ ⁺ . In some embodiments, a time-of-flight secondary ion mass spectrometry test is used, and the protective layer includes at least one of the following positively charged groups: C ₂ H ₃ ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₅ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ or C ₈ H ₁₁ N ₂ ⁺ . In some embodiments, a time-of-flight secondary ion mass spectrometry test is used, and the protective layer includes at least one of the following positively charged groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₃ H ₅ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₉ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₂ OC ₅ H ₁₅ ⁺ , Si ₃ O ₃ C ₅ H ₁₅ ⁺ or Si ₃ O ₂ C ₇ H ₂₁ ⁺ . Fig. 1 shows a time-of-flight secondary ion mass spectrometry (TOF-SIMS) diagram of a negative active material according to the present application, wherein the TOF-SIMS test is used, and the protective layer of the negative active material can excite positively charged ions.

在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括带负电基团。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带负电基团中的至少一种：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、SiO ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、PO ₃ ^-、C ₅H ₇N ^-、C ₁₄H ₂₁O ^-或Si ₃O ₄C ₅H ₁₅ ^-。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带负电基团中的至少一种：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、PO ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、PO ₃ ^-、C ₅H ₇N ^-或C ₁₄H ₂₁O ^-。在一些实施例中，采用飞行时间二次离子质谱测试，所述保护层包括以下带负电基团中的至少一种：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₂H ₃O ₂ ^-、PO ₂ ^-、C ₄H ₇O ^-、SiO ₂CH ₃ ^-、C ₅H ₇N ^-、Si ₂O ₃C ₃H ₉ ^-、C ₁₄H ₂₁O ^-或Si ₃O ₄C ₅H ₁₅ ^-。图2展示了根据本申请的一负极活性材料的飞行时间二次离子质谱(TOF-SIMS)图，其中采用TOF-SIMS测试，所述负极活性材料的保护层可激发出带正电离子。 In some embodiments, time-of-flight secondary ion mass spectrometry is used, and the protective layer includes negatively charged groups. In some embodiments, using time of flight secondary ion mass spectrometry, the protective layer comprising a negatively charged group at least one ^{^{of: CH -, O -, CN}} -, C 3 H 2 -, C 4 H - _{_{_{^{, C 2 H 3 O 2 -}}}} , SiO 2 -, C 4 H 7 O -, C 3 H 9 N 2 -, PO 3 -, C 5 H 7 N -, C 14 H 21 O - or Si ₃ O ₄ C ₅ H ₁₅ ^-. In some embodiments, using time of flight secondary ion mass spectrometry, the protective layer comprising a negatively charged group at least one ^{^{of: CH -, O -, CN}} -, C 3 H 2 -, C 2 HO - _{^{_{, C 4 H -, C 2}}} H 3 O 2 -, PO 2 -, C 4 H 7 O -, C 3 H 9 N 2 -, PO 3 -, C 5 H 7 N - or C ₁₄ H ₂₁ O ^- . In some embodiments, using time of flight secondary ion mass spectrometry, the protective layer comprising a negatively charged group at least one ^{^{of: CH -, O -, CN}} -, C 3 H 2 -, C 2 HO - _{_{_{^{, C 2 H 3 O 2 -}}}} , PO 2 -, C 4 H 7 O -, SiO 2 CH 3 -, C 5 H 7 N -, Si 2 O 3 C 3 H 9 -, C 14 H 21 O - , or _{_{_{_{si 3 O 4 C 5 H 15}}}} -. Fig. 2 shows a time-of-flight secondary ion mass spectrometry (TOF-SIMS) diagram of a negative active material according to the present application, wherein the TOF-SIMS test is used, and the protective layer of the negative active material can excite positively charged ions.

采用飞行时间二次离子质谱测试，从负极活性材料的保护层激发的出二次离子带电基团的种类和数量会受负极制备过程中表面电化学处理方法和烧结处理的程度及温度等影响。这些基团会参与锂离子嵌入和脱出的过程。当所述带电基团中存在含氧基团时，锂易与端部原子生成电荷转移化合物，导致活性锂离子的量减少，其可能会导致电压滞后现象。此外，含氧基团极易吸附空间水，其易与锂反应生成氢氧化锂和碳酸锂，二者均为固体电解质薄膜的重要组成部分，有助于形成更为稳定的负极材料与电解液之间的界面，从而改善全电池的长循环性能和安全性能(例如，热冲击、过充、穿钉、撞击)。Using time-of-flight secondary ion mass spectrometry test, the type and number of secondary ion charged groups excited from the protective layer of the negative electrode active material will be affected by the surface electrochemical treatment method, the degree of sintering treatment and the temperature during the preparation of the negative electrode. These groups will participate in the process of lithium ion insertion and extraction. When there is an oxygen-containing group in the charged group, lithium is likely to form a charge transfer compound with the end atom, resulting in a decrease in the amount of active lithium ions, which may cause a voltage hysteresis phenomenon. In addition, oxygen-containing groups are very easy to adsorb space water, and they easily react with lithium to produce lithium hydroxide and lithium carbonate, both of which are important components of solid electrolyte membranes, which help to form more stable negative electrode materials and electrolytes. In order to improve the long-cycle performance and safety performance of the full battery (for example, thermal shock, overcharge, nail penetration, impact).

根据本申请的实施例，基于所述负极活性材料的总重量计，所述保护层的含量为不大于1wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述保护层的含量为不大于0.5wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述保护层的含量为不大于0.1wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述保护层的含量为0.01wt％、0.03wt％、0.05wt％、0.08wt％、0.1wt％、0.3wt％、0.5wt％、0.8wt％或1wt％。According to an embodiment of the present application, based on the total weight of the negative active material, the content of the protective layer is not more than 1 wt%. In some embodiments, based on the total weight of the negative active material, the content of the protective layer is not more than 0.5 wt%. In some embodiments, based on the total weight of the negative active material, the content of the protective layer is not more than 0.1 wt%. In some embodiments, based on the total weight of the negative active material, the content of the protective layer is 0.01 wt%, 0.03 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.3 wt%, 0.5 wt% %, 0.8wt% or 1wt%.

根据本申请的实施例，由拉曼光谱法测试得到的所述负极活性材料在1345cm ^-1至1355cm ^-1处出现的峰的半高峰宽Id与在1595cm ^-1至1605cm ^-1处出现的峰的半高峰宽Ig的比值Id/Ig为0.7至1.5，所述负极活性材料包括结晶碳材料、无定形碳材料或其组合。在一些实施例中，由拉曼光谱法测试得到的所述负极活性材料的Id/Ig为1.0至1.2。在一些实施例中，由拉曼光谱法测试得到的所述负极活性材料的Id/Ig为0.7、0.8、0.9、1.0、1.1、1.2、1.3、1.4或1.5。当负极活性材料的Id/Ig在上述范围内时，负极活性材料表面的晶体缺陷及无序化程度在适宜的范围内，有助于提高负极活性材料的克容量。 According to the embodiment of the present application, the half-height width Id of the peak appearing ^{at 1345 cm -1} to 1355 cm ^-1 of the negative electrode active material measured by Raman spectroscopy and ^{the peak appearing at 1595 cm -1} to 1605 cm ^-1 The ratio Id/Ig of the half-height peak width Ig is 0.7 to 1.5, and the negative electrode active material includes crystalline carbon material, amorphous carbon material, or a combination thereof. In some embodiments, the Id/Ig of the negative active material measured by Raman spectroscopy is 1.0 to 1.2. In some embodiments, the Id/Ig of the negative active material measured by Raman spectroscopy is 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, or 1.5. When the Id/Ig of the negative electrode active material is in the above range, the crystal defects and the degree of disorder on the surface of the negative electrode active material are in an appropriate range, which helps to increase the gram capacity of the negative electrode active material.

根据本申请的实施例，所述负极活性材料还包含金属元素，所述金属元素包含金、银、铂、锆、锌、镁、钙、钡、钒、铁或铝中的至少一种。According to an embodiment of the present application, the negative active material further includes a metal element, and the metal element includes at least one of gold, silver, platinum, zirconium, zinc, magnesium, calcium, barium, vanadium, iron, or aluminum.

根据本申请的实施例，基于所述负极活性材料的总重量，所述金属元素的含量小于0.1wt％。在一些实施例中，基于所述负极活性材料的总重量，所述金属元素的含量小于0.05wt％。基于所述负极活性材料的总重量，所述金属元素的含量为0.005wt％、0.01wt％、0.03wt％、0.05wt％、0.08wt％或0.1wt％。According to an embodiment of the present application, based on the total weight of the negative active material, the content of the metal element is less than 0.1 wt%. In some embodiments, based on the total weight of the negative active material, the content of the metal element is less than 0.05 wt%. Based on the total weight of the negative active material, the content of the metal element is 0.005wt%, 0.01wt%, 0.03wt%, 0.05wt%, 0.08wt% or 0.1wt%.

根据本申请的实施例，所述负极活性材料进一步包含非金属元素，所述非金属元素包括硼、砷或硒中的至少一种。According to an embodiment of the present application, the negative active material further includes a non-metal element, and the non-metal element includes at least one of boron, arsenic, or selenium.

根据本申请的实施例，基于所述负极活性材料的总重量，所述非金属元素的含量为50ppm至200ppm。在一些实施例中，基于所述负极活性材料的总重量，所述非金属元素的含量为100ppm至150ppm。在一些实施例中，基于所述负极活性材料的总重量，所述非金属元素的含量为50ppm、60ppm、70ppm、80ppm、90ppm、100ppm、110ppm、120ppm、130ppm、140ppm、150ppm、160ppm、170ppm、180ppm、190ppm或200ppm。According to an embodiment of the present application, based on the total weight of the negative active material, the content of the non-metal element is 50 ppm to 200 ppm. In some embodiments, the content of the non-metal element is 100 ppm to 150 ppm based on the total weight of the negative active material. In some embodiments, based on the total weight of the negative active material, the content of the non-metal elements is 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140 ppm, 150 ppm, 160 ppm, 170 ppm, 180ppm, 190ppm or 200ppm.

根据本申请的实施例，所述负极活性材料包含孔道，所述孔道的内壁包含金属元素，和/或非金属元素。具有孔道的负极活性材料的比表面积较大，孔道内壁可有效吸附锂，有助于提升负极活性材料的电化学容量。According to an embodiment of the present application, the negative active material includes pores, and the inner walls of the pores include metallic elements and/or non-metallic elements. The negative electrode active material with pores has a larger specific surface area, and the inner wall of the pores can effectively adsorb lithium, which helps to increase the electrochemical capacity of the negative electrode active material.

根据本申请的实施例，所述功能材料的厚度为30nm至250nm。所述功能材料的厚度为50nm至200nm。在一些实施例中，所述功能材料的厚度为100nm至150nm。在一些实施例中，所述功能材料的厚度为30nm、50nm、80nm、100nm、120nm、125nm、150nm、180nm、200nm、220nm或250nm。According to an embodiment of the present application, the thickness of the functional material is 30 nm to 250 nm. The thickness of the functional material is 50 nm to 200 nm. In some embodiments, the thickness of the functional material is 100 nm to 150 nm. In some embodiments, the thickness of the functional material is 30 nm, 50 nm, 80 nm, 100 nm, 120 nm, 125 nm, 150 nm, 180 nm, 200 nm, 220 nm, or 250 nm.

根据本申请的实施例，所述负极活性材料包含磷(P)元素，基于所述负极活性材料的总重量计，所述磷元素的含量不大于1wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述磷元素的含量不大于0.5wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述磷元素的含量不大于0.1wt％。在一些实施例中，基于所述负极活性材料的总重量计，所述P元素的含量为0.01wt％、0.03wt％、0.05wt％、0.08wt％、0.1wt％、0.3wt％、0.5wt％、0.8wt％或1wt％。负极活性材料层P元素的含量可通过元素分析仪测试得到。当磷元素在负极活性材料中的含量在上述范围内时，负极活性材料的脱锂电位可在0-0.7V范围内调控。脱锂电位越低，锂离子电池的能量密度越高。According to an embodiment of the present application, the negative electrode active material includes phosphorus (P) element, and based on the total weight of the negative electrode active material, the content of the phosphorus element is not more than 1 wt%. In some embodiments, based on the total weight of the negative active material, the content of the phosphorus element is not more than 0.5 wt%. In some embodiments, based on the total weight of the negative active material, the content of the phosphorus element is not more than 0.1 wt%. In some embodiments, based on the total weight of the negative active material, the content of the element P is 0.01 wt%, 0.03 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.3 wt%, 0.5 wt %, 0.8wt% or 1wt%. The content of P element in the negative electrode active material layer can be measured by an element analyzer. When the content of the phosphorus element in the negative electrode active material is within the above range, the delithiation potential of the negative electrode active material can be adjusted in the range of 0-0.7V. The lower the delithiation potential, the higher the energy density of the lithium ion battery.

根据本申请的实施例，所述磷元素存在于所述孔道的内壁。According to an embodiment of the present application, the phosphorus element is present on the inner wall of the pore.

根据本申请的实施例，所述磷元素在所述负极活性材料中由外至内逐渐减少。磷元素在负极活性材料中的分布可通过扫描电子显微镜能谱(EDS)得到。According to the embodiment of the present application, the phosphorus element gradually decreases from the outside to the inside in the negative active material. The distribution of phosphorus element in the negative electrode active material can be obtained by scanning electron microscopy energy spectroscopy (EDS).

根据本申请的实施例，所述负极活性材料的中值粒径为5μm至20μm。在一些实施例中，所述负极活性材料的中值粒径为10μm至15μm。在一些实施例中，所述负极活性材料的中值粒径为5μm、8μm、10μm、12μm、15μm、18μm或20μm。According to an embodiment of the present application, the median particle diameter of the negative active material is 5 μm to 20 μm. In some embodiments, the median particle diameter of the negative active material is 10 μm to 15 μm. In some embodiments, the median particle size of the negative active material is 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, or 20 μm.

根据本申请的实施例，所述负极活性材料的比表面积为0.7m ²/g至100m ²/g。在一些实施例中，所述负极活性材料的比表面积为1m ²/g至80m ²/g。在一些实施例中，所述负极活性材料的比表面积为10m ²/g至60m ²/g。在一些实施例中，所述负极活性材料的比表面积为30m ²/g至50m ²/g。在一些实施例中，所述负极活性材料的比表面积为0.7m ²/g、1m ²/g、5m ²/g、10m ²/g、20m ²/g、30m ²/g、40m ²/g、50m ²/g、60m ²/g、70m ²/g、80m ²/g、90m ²/g或100m ²/g。提升负极活性材料的比表面积可增加负极活性材料与电解液的接触位点。负极活性材料的比表面积可通过氮气吸附测试方法得到。 According to an embodiment of the present application, the specific surface area of the negative active material is 0.7 m ² /g to 100 m ² /g. In some embodiments, the specific surface area of the negative active material is 1 m ² /g to 80 m ² /g. In some embodiments, the specific surface area of the negative active material is 10 m ² /g to 60 m ² /g. In some embodiments, the specific surface area of the negative active material is 30 m ² /g to 50 m ² /g. In some embodiments, the specific surface area of the negative active material is 0.7m ² /g, 1m ² /g, 5m ² /g, 10m ² /g, 20m ² /g, 30m ² /g, 40m ² /g , 50m ² /g, 60m ² /g, 70m ² /g, 80m ² /g, 90m ² /g or 100m ² /g. Increasing the specific surface area of the negative active material can increase the contact point of the negative active material with the electrolyte. The specific surface area of the negative electrode active material can be obtained by the nitrogen adsorption test method.

在一些实施方案中，负极活性材料可包括，但不限于，天然石墨、人造石墨、中间相微碳球(简称为MCMB)、硬碳、软碳、硅、硅-碳复合物、Li-Sn合金、Li-Sn-O合金、Sn、SnO、SnO ₂、尖晶石结构的锂化TiO ₂-Li ₄Ti ₅O ₁₂或LI-l合金。碳材料的非限制性示例包括结晶碳、非晶碳和它们的混合物。结晶碳可以是无定形的或片形的、小片形的、球形的或纤维状的天然石墨或人造石墨。非晶碳可以是软碳、硬碳、中间相沥青碳化物、煅烧焦等。 In some embodiments, the negative active material may include, but is not limited to, natural graphite, artificial graphite, mesophase carbon microspheres (referred to as MCMB for short), hard carbon, soft carbon, silicon, silicon-carbon composite, Li-Sn Alloy, Li-Sn-O alloy, Sn, SnO, SnO ₂ , spinel structure lithiated TiO ₂ -Li ₄ Ti ₅ O ₁₂ or LI-l alloy. Non-limiting examples of carbon materials include crystalline carbon, amorphous carbon, and mixtures thereof. The crystalline carbon may be amorphous or flake-shaped, flake-shaped, spherical or fibrous natural graphite or artificial graphite. Amorphous carbon can be soft carbon, hard carbon, mesophase pitch carbide, calcined coke, and the like.

负极negative electrode

负极包括负极集流体和负极活性材料层，所述负极活性材料层设置在所述负极集流体上。所述负极活性材料层包括根据本申请所述的负极活性材料。The negative electrode includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is disposed on the negative electrode current collector. The negative active material layer includes the negative active material according to the present application.

用于本申请所述的负极集流体可以选自铜箔、镍箔、不锈钢箔、钛箔、泡沫镍、泡沫铜、覆有导电金属的聚合物基底和它们的组合。The negative electrode current collector used in the present application may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, foamed nickel, foamed copper, polymer substrates coated with conductive metals, and combinations thereof.

根据本申请的实施例，所述负极活性材料层的孔隙率为15％至45％。在一些实施例中，所述负极活性材料层的孔隙率为20％至40％。在一些实施例中，所述负极活性材料层的孔隙率为25％至30％。在一些实施例中，所述负极活性材料层的孔隙率为15％、20％、25％、30％、35％、40％或45％。负极活性材料层的孔隙率可通过控制负极制备过程中辊压压力来实现。通过控制辊压压力，可实现负极活性材料层厚度的连续变化，从而可控制负极活性材料层的孔隙率。具体地，可根据《铁矿石表观密度、真密度和孔隙率的测定GB/T 24586-2009》标准，采用测试仪器AccuPyc II 1340，通过质量体积法计算负极活性材料层的孔隙率。当负极活性材料层的孔隙率在上述范围内时，有助于改善电化学装置的能量密度。According to an embodiment of the present application, the porosity of the negative active material layer is 15% to 45%. In some embodiments, the porosity of the negative active material layer is 20% to 40%. In some embodiments, the porosity of the negative active material layer is 25% to 30%. In some embodiments, the porosity of the negative active material layer is 15%, 20%, 25%, 30%, 35%, 40%, or 45%. The porosity of the negative active material layer can be achieved by controlling the rolling pressure during the preparation of the negative electrode. By controlling the rolling pressure, a continuous change in the thickness of the negative active material layer can be achieved, so that the porosity of the negative active material layer can be controlled. Specifically, according to the "Determination of Apparent Density, True Density and Porosity of Iron Ore GB/T 24586-2009" standard, the test instrument AccuPyc II 1340 can be used to calculate the porosity of the negative electrode active material layer by the mass volume method. When the porosity of the anode active material layer is within the above range, it helps to improve the energy density of the electrochemical device.

根据本申请的实施例，所述负极活性材料层相对所述电解液的接触角为80°至96°。图3展示了负极相对电解液的接触角α的示意图。在一些实施例中，所述负极活性材料层相对所述电解液的接触角α为80°、81°、82°、83°、84°、85°、86°、87°、88°、89°、90°、91°、92°、93°、94°、95°或96°。负极活性材料层相对电解液的接触角可通过任何已知手段进行测试，例如使用上海中辰(型号为JC2000D1)测试仪进行测试。According to an embodiment of the present application, the contact angle of the negative active material layer with respect to the electrolyte is 80° to 96°. Figure 3 shows a schematic diagram of the contact angle α of the negative electrode with respect to the electrolyte. In some embodiments, the contact angle α of the negative active material layer with respect to the electrolyte is 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°. °, 90°, 91°, 92°, 93°, 94°, 95° or 96°. The contact angle of the negative electrode active material layer with respect to the electrolyte can be tested by any known means, for example, using a Shanghai Zhongchen (model JC2000D1) tester.

根据本申请的实施例，所述负极进一步包括导电层，所述导电层设置于所述负极活性材料层和所述负极集流体之间。在一些实施方案中，所述导电层的导电材料可以包括任何导电材料，只要它不引起化学变化。导电材料的非限制性示例包括基于碳的材料(例如，天然石墨、人造石墨、碳黑、乙炔黑、科琴黑、碳纤维、碳纳米管、石墨烯等)、基于金属的材料(例如，金属粉、金属纤维等，例如铜、镍、铝、银等)、导电聚合物(例如，聚亚苯基衍生物)和它们的混合物。According to an embodiment of the present application, the negative electrode further includes a conductive layer disposed between the negative active material layer and the negative current collector. In some embodiments, the conductive material of the conductive layer may include any conductive material as long as it does not cause a chemical change. Non-limiting examples of conductive materials include carbon-based materials (e.g., natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanotubes, graphene, etc.), metal-based materials (e.g., metal Powder, metal fibers, etc., such as copper, nickel, aluminum, silver, etc.), conductive polymers (e.g., polyphenylene derivatives), and mixtures thereof.

根据本申请的实施例，所述负极进一步包括粘结剂，所述粘结剂选自以下的至少一种：聚乙烯醇、羧甲基纤维素、羟丙基纤维素、二乙酰基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚偏1，1-二氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂或尼龙等。According to an embodiment of the present application, the negative electrode further includes a binder, and the binder is selected from at least one of the following: polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, and diacetyl cellulose , Polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, poly Propylene, styrene butadiene rubber, acrylic (ester) styrene butadiene rubber, epoxy resin or nylon, etc.

正极positive electrode

正极包括正极集流体和设置在所述正极集流体上的正极活性材料。正极活性材料的具体种类均不受到具体的限制，可根据需求进行选择。The positive electrode includes a positive electrode current collector and a positive electrode active material provided on the positive electrode current collector. The specific types of positive electrode active materials are not subject to specific restrictions, and can be selected according to requirements.

在一些实施方案中，正极活性材料包括够吸收和释放锂(Li)的正极材料。能够吸收/释放锂(Li)的正极材料的例子可以包括钴酸锂、镍钴锰酸锂、镍钴铝酸锂、锰酸锂、磷酸锰铁锂、磷酸钒锂、磷酸钒氧锂、磷酸铁锂、钛酸锂和富锂锰基材料。In some embodiments, the positive electrode active material includes a positive electrode material capable of absorbing and releasing lithium (Li). Examples of positive electrode materials capable of absorbing/releasing lithium (Li) may include lithium cobalt oxide, lithium nickel cobalt manganate, lithium nickel cobalt aluminate, lithium manganate, lithium iron manganese phosphate, lithium vanadium phosphate, lithium vanadyl phosphate, and phosphoric acid. Lithium iron, lithium titanate and lithium-rich manganese-based materials.

具体的，钴酸锂的化学式可以如化学式1：Specifically, the chemical formula of lithium cobalt oxide can be as chemical formula 1:

Li _xCo _aM1 _bO _2-c化学式1 Li _x Co _a M1 _b O _2-c Chemical formula 1

其中M1表示选自镍(Ni)、锰(Mn)、镁(Mg)、铝(Al)、硼(B)、钛(Ti)、钒(V)、铬(Cr)、铁(Fe)、铜(Cu)、锌(Zn)、钼(Mo)、锡(Sn)、钙(Ca)、锶(Sr)、钨(W)、钇(Y)、镧(La)、锆(Zr)和硅(Si)中的至少一种，x、a、b和c值分别在以下范围内：0.8≤x≤1.2、0.8≤a≤1、0≤b≤0.2、-0.1≤c≤0.2。Wherein M1 represents selected from nickel (Ni), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), Copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), tungsten (W), yttrium (Y), lanthanum (La), zirconium (Zr) and For at least one of silicon (Si), the values of x, a, b, and c are within the following ranges: 0.8≤x≤1.2, 0.8≤a≤1, 0≤b≤0.2, -0.1≤c≤0.2.

镍钴锰酸锂或镍钴铝酸锂的化学式可以如化学式2：The chemical formula of lithium nickel cobalt manganate or lithium nickel cobalt aluminate can be as chemical formula 2:

Li _yNi _dM2 _eO _2-f化学式2 Li _y Ni _d M2 _e O _2-f Chemical formula 2

其中M2表示选自钴(Co)、锰(Mn)、镁(Mg)、铝(Al)、硼(B)、钛(Ti)、钒(V)、铬(Cr)、铁(Fe)、铜(Cu)、锌(Zn)、钼(Mo)、锡(Sn)、钙(Ca)、锶(Sr)、钨(W)、锆(Zr)和硅(Si)中的至少一种，y、d、e和f值分别在以下范围内：0.8≤y≤1.2、0.3≤d≤0.98、0.02≤e≤0.7、-0.1≤f≤0.2。Wherein M2 represents selected from cobalt (Co), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), At least one of copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), tungsten (W), zirconium (Zr), and silicon (Si), The values of y, d, e, and f are in the following ranges: 0.8≤y≤1.2, 0.3≤d≤0.98, 0.02≤e≤0.7, -0.1≤f≤0.2.

锰酸锂的化学式可以如化学式3：The chemical formula of lithium manganate can be as chemical formula 3:

Li _zMn _2-gM3 _gO _4-h化学式3 Li _z Mn _2-g M3 _g O _4-h Chemical formula 3

其中M3表示选自钴(Co)、镍(Ni)、镁(Mg)、铝(Al)、硼(B)、钛(Ti)、钒(V)、铬(Cr)、铁(Fe)、铜(Cu)、锌(Zn)、钼(Mo)、锡(Sn)、钙(Ca)、锶(Sr)和钨(W)中的至少一种，z、g和h值分别在以下范围内：0.8≤z≤1.2、0≤g＜1.0和-0.2≤h≤0.2。Wherein M3 represents selected from cobalt (Co), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), At least one of copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W), with z, g and h values in the following ranges respectively Inner: 0.8≤z≤1.2, 0≤g≤1.0 and -0.2≤h≤0.2.

在一些实施例中，所述正极活性材料层的重量是所述负极活性材料层的重量的1.5至15倍。在一些实施例中，所述正极活性材料层的重量是所述负极活性材料层的重量的3至10倍。在一些实施例中，所述正极活性材料层的重量是所述负极活性材料层的重量的5至8倍。在一些实施例中，所述正极活性材料层的重量是所述负极活性材料层的重量的1.5倍、2倍、3倍、4倍、5倍、6倍、7倍、8倍、9倍、10倍、11倍、12倍、13倍、14倍或15倍。In some embodiments, the weight of the positive electrode active material layer is 1.5 to 15 times the weight of the negative electrode active material layer. In some embodiments, the weight of the positive active material layer is 3 to 10 times the weight of the negative active material layer. In some embodiments, the weight of the positive active material layer is 5 to 8 times the weight of the negative active material layer. In some embodiments, the weight of the positive active material layer is 1.5 times, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times the weight of the negative active material layer. , 10 times, 11 times, 12 times, 13 times, 14 times or 15 times.

在一些实施例中，正极活性材料层可以在表面上具有涂层，或者可以与具有涂层的另一化合物混合。所述涂层可以包括从涂覆元素的氧化物、涂覆元素的氢氧化物、涂覆元素的羟基氧化物、涂覆元素的碳酸氧盐(oxycarbonate)和涂覆元素的羟基碳酸盐(hydroxycarbonate)中选择的至少一种涂覆元素化合物。用于涂层的化合物可以是非晶的或结晶的。在涂层中含有的涂覆元素可以包括Mg、Al、Co、K、Na、Ca、Si、Ti、V、Sn、Ge、Ga、B、As、Zr、F或它们的混合物。可以通过任何方法来施加涂层，只要所述方法不对正极活性材料的性能产生不利影响即可。例如，所述方法可以包括对本领域普通技术人员来说众所周知的任何涂覆方法，例如喷涂、浸渍等。In some embodiments, the positive active material layer may have a coating on the surface, or may be mixed with another compound having a coating. The coating may include oxides of coating elements, hydroxides of coating elements, oxyhydroxides of coating elements, oxycarbonates of coating elements, and hydroxycarbonates of coating elements ( At least one coating element compound selected from hydroxycarbonate). The compound used for the coating may be amorphous or crystalline. The coating element contained in the coating may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, F, or a mixture thereof. The coating can be applied by any method as long as the method does not adversely affect the performance of the positive electrode active material. For example, the method may include any coating method well-known to those of ordinary skill in the art, such as spraying, dipping, and the like.

在一些实施方案中，正极活性材料层还包含粘合剂，并且可选地还包括正极导电材料。In some embodiments, the positive active material layer further includes a binder, and optionally further includes a positive conductive material.

粘合剂可提高正极活性材料颗粒彼此间的结合，并且还提高正极活性材料与集流体的结合。粘合剂的非限制性示例包括聚乙烯醇、羟丙基纤维素、二乙酰基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚偏1，1-二氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂、尼龙等。The binder can improve the binding of the positive electrode active material particles to each other, and also improve the binding of the positive electrode active material to the current collector. Non-limiting examples of binders include polyvinyl alcohol, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinyl chloride Vinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene butadiene rubber, acrylic (ester) styrene butadiene rubber, epoxy resin, nylon, etc.

正极活性材料层包括正极导电材料，从而赋予电极导电性。所述正极导电材料可以包括任何导电材料，只要它不引起化学变化。正极导电材料的非限制性示例包括基于碳的材料(例如，天然石墨、人造石墨、碳黑、乙炔黑、科琴黑、碳纤维等)、基于金属的材料(例如，金属粉、金属纤维等，包括例如铜、镍、铝、银等)、导电聚合物(例如，聚亚苯基衍生物)和它们的混合物。The positive electrode active material layer includes a positive electrode conductive material, thereby imparting conductivity to the electrode. The positive electrode conductive material may include any conductive material as long as it does not cause a chemical change. Non-limiting examples of positive electrode conductive materials include carbon-based materials (e.g., natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, etc.), metal-based materials (e.g., metal powder, metal fiber, etc., Including, for example, copper, nickel, aluminum, silver, etc.), conductive polymers (for example, polyphenylene derivatives), and mixtures thereof.

用于根据本申请的电化学装置的正极集流体可以是铝(Al)，但不限于此。The positive electrode current collector used in the electrochemical device according to the present application may be aluminum (Al), but is not limited thereto.

电解液Electrolyte

可用于本申请实施例的电解液可以为现有技术中已知的电解液。The electrolyte that can be used in the embodiments of the present application may be an electrolyte known in the prior art.

可用于本申请实施例的电解液中的电解质包括，但不限于：无机锂盐，例如LiClO ₄、LiAsF ₆、LiPF ₆、LiBF ₄、LiSbF ₆、LiSO ₃F、LiN(FSO ₂) ₂等；含氟有机锂盐，例如LiCF ₃SO ₃、LiN(FSO ₂)(CF ₃SO ₂)、LiN(CF ₃SO ₂) ₂、LiN(C ₂F ₅SO ₂) ₂、环状1，3-六氟丙烷二磺酰亚胺锂、环状1，2-四氟乙烷二磺酰亚胺锂、LiN(CF ₃SO ₂)(C ₄F ₉SO ₂)、LiC(CF ₃SO ₂) ₃、LiPF ₄(CF ₃) ₂、LiPF ₄(C ₂F ₅) ₂、LiPF ₄(CF ₃SO ₂) ₂、LiPF ₄(C ₂F ₅SO ₂) ₂、LiBF ₂(CF ₃) ₂、LiBF2(C2F5)2、LiBF ₂(CF ₃SO ₂) ₂、LiBF ₂(C ₂F ₅SO ₂) ₂；含二羧酸配合物锂盐，例如双(草酸根合)硼酸锂、二氟草酸根合硼酸锂、三(草酸根合)磷酸锂、二氟双(草酸根合)磷酸锂、四氟(草酸根合)磷酸锂等。另外，上述电解质可以单独使用一种，也可以同时使用两种或两种以上。在一些实施例中，电解质包括LiPF ₆和LiBF ₄的组合。在一些实施例中，电解质包括LiPF ₆或LiBF ₄等无机锂盐与LiCF ₃SO ₃、LiN(CF ₃SO ₂) ₂、LiN(C ₂F ₅SO ₂) ₂等含氟有机锂盐的组合。在一些实施例中，电解质包括LiPF ₆。 The electrolyte that can be used in the electrolyte in the embodiments of the present application includes, but is not limited to: inorganic lithium salts, such as LiClO ₄ , LiAsF ₆ , LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiSO ₃ F, LiN(FSO ₂ ) _2, etc.; Fluorine-containing organic lithium salts, such as LiCF ₃ SO ₃ , LiN(FSO ₂ )(CF ₃ SO ₂ ), LiN(CF ₃ SO ₂ ) ₂ , LiN(C ₂ F ₅ SO ₂ ) ₂ , cyclic 1,3- Lithium hexafluoropropane disulfonimide, lithium cyclic 1,2-tetrafluoroethane disulfonimide, LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ), LiC (CF ₃ SO ₂ ) _3. LiPF ₄ (CF ₃ ) ₂ , LiPF ₄ (C ₂ F ₅ ) ₂ , LiPF ₄ (CF ₃ SO ₂ ) ₂ , LiPF ₄ (C ₂ F ₅ SO ₂ ) ₂ , LiBF ₂ (CF ₃ ) ₂ , LiBF2(C2F5)2, LiBF ₂ (CF ₃ SO ₂ ) ₂ , LiBF ₂ (C ₂ F ₅ SO ₂ ) ₂ ; Lithium salt containing dicarboxylic acid complex, such as bis(oxalato) lithium borate, difluorooxalic acid Lithium borate, tris(oxalato) lithium phosphate, difluorobis(oxalato) lithium phosphate, tetrafluoro(oxalato) lithium phosphate, etc. In addition, the above-mentioned electrolytes may be used singly, or two or more of them may be used at the same time. In some embodiments, the electrolyte includes a combination of _{LiPF 6} and LiBF _4. In some embodiments, the electrolyte includes a combination of an inorganic lithium salt such as _{LiPF 6} or LiBF ₄ and a fluorine-containing organic lithium salt such as _{LiCF 3} SO ₃ , LiN(CF ₃ SO ₂ ) ₂ , and LiN(C ₂ F ₅ SO ₂ ) ₂ . In some embodiments, the electrolyte includes LiPF ₆ .

在一些实施例中，电解质的浓度在0.8-3mol/L的范围内，例如0.8-2.5mol/L的范围内、0.8-2mol/L的范围内、1-2mol/L的范围内、又例如为1mol/L、1.15mol/L、1.2mol/L、1.5mol/L、2mol/L或2.5mol/L。In some embodiments, the concentration of the electrolyte is in the range of 0.8-3 mol/L, for example, in the range of 0.8-2.5 mol/L, in the range of 0.8-2 mol/L, in the range of 1-2 mol/L, for example It is 1mol/L, 1.15mol/L, 1.2mol/L, 1.5mol/L, 2mol/L or 2.5mol/L.

可用于本申请实施例的电解液中的溶剂包括，但不限于：碳酸酯化合物、基于酯的化合物、基于醚的化合物、基于酮的化合物、基于醇的化合物、非质子溶剂或它们的组合。Solvents that can be used in the electrolyte of the embodiments of the present application include, but are not limited to: carbonate compounds, ester-based compounds, ether-based compounds, ketone-based compounds, alcohol-based compounds, aprotic solvents, or combinations thereof.

碳酸酯化合物的实例包括，但不限于，链状碳酸酯化合物、环状碳酸酯化合物、氟代碳酸酯化合物或它们的组合。Examples of carbonate compounds include, but are not limited to, linear carbonate compounds, cyclic carbonate compounds, fluorocarbonate compounds, or combinations thereof.

链状碳酸酯化合物的实例包括，但不限于，碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸甲乙酯(MEC)及它们的组合。所述环状碳酸酯化合物的实例为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)、碳酸乙烯基亚乙酯(VEC)及它们的组合。所述氟代碳酸酯化合物的实例为碳酸氟代亚乙酯(FEC)、碳酸1，2-二氟亚乙酯、碳酸1，1-二氟亚乙酯、碳酸1，1，2-三氟亚乙酯、碳酸1，1，2，2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1，2-二氟-1-甲基亚乙酯、碳酸1，1，2-三氟-2-甲基亚乙酯、碳酸三氟甲基亚乙酯及它们的组合。Examples of chain carbonate compounds include, but are not limited to, diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethylene propyl carbonate ( EPC), ethyl methyl carbonate (MEC) and their combinations. Examples of the cyclic carbonate compound are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinyl ethylene carbonate (VEC), and combinations thereof. Examples of the fluorocarbonate compound are fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate Fluoroethylene, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2 carbonate -Difluoro-1-methylethylene, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, and combinations thereof.

基于酯的化合物的实例包括，但不限于，乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸叔丁酯、丙酸甲酯、丙酸乙酯、γ-丁内酯、癸内酯、戊内酯、甲瓦龙酸内酯、己内酯、甲酸甲酯及它们的组合。Examples of ester-based compounds include, but are not limited to, methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, decanolide, Valerolactone, mevalonolactone, caprolactone, methyl formate, and combinations thereof.

基于醚的化合物的实例包括，但不限于，二丁醚、四甘醇二甲醚、二甘醇二甲醚、1，2-二甲氧基乙烷、1，2-二乙氧基乙烷、乙氧基甲氧基乙烷、2-甲基四氢呋喃、四氢呋喃及它们的组合。Examples of ether-based compounds include, but are not limited to, dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane Alkanes, ethoxymethoxyethane, 2-methyltetrahydrofuran, tetrahydrofuran, and combinations thereof.

基于酮的化合物的实例包括，但不限于，环己酮。Examples of ketone-based compounds include, but are not limited to, cyclohexanone.

基于醇的化合物的实例包括，但不限于，乙醇和异丙醇。Examples of alcohol-based compounds include, but are not limited to, ethanol and isopropanol.

非质子溶剂的实例包括，但不限于，二甲亚砜、1，2-二氧戊环、环丁砜、甲基环丁砜、1，3-二甲基-2-咪唑烷酮、N-甲基-2-吡咯烷酮、甲酰胺、二甲基甲酰胺、乙腈、硝基甲烷、磷酸三甲酯、磷酸三乙酯、磷酸三辛酯、和磷酸酯及它们的组合。Examples of aprotic solvents include, but are not limited to, dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl- 2-pyrrolidone, formamide, dimethylformamide, acetonitrile, nitromethane, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, and phosphate esters and combinations thereof.

隔离膜Isolation film

在一些实施方案中，正极与负极之间设有隔离膜以防止短路。可用于本申请的实施例中使用的隔离膜的材料和形状没有特别限制，其可为任何现有技术中公开的技术。在一些实施方案中，隔离膜包括由对本申请的电解液稳定的材料形成的聚合物或无机物等。In some embodiments, a separator is provided between the positive electrode and the negative electrode to prevent short circuits. The material and shape of the isolation film that can be used in the embodiments of the present application are not particularly limited, and they can be any technology disclosed in the prior art. In some embodiments, the isolation membrane includes a polymer or an inorganic substance formed of a material that is stable to the electrolyte of the present application, or the like.

例如，隔离膜可包括基材层和表面处理层。基材层为具有多孔结构的无纺布、膜或复合膜，基材层的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯和聚酰亚胺中的至少一种。具体的，可选用聚丙烯多孔膜、聚乙烯多孔膜、聚丙烯无纺布、聚乙烯无纺布或聚丙烯-聚乙烯-聚丙烯多孔复合膜。多孔结构可以提升隔离膜的耐热性能、抗氧化性能和电解质浸润性能，增强隔离膜与极片之间的粘接性。For example, the isolation film may include a substrate layer and a surface treatment layer. The substrate layer is a non-woven fabric, film or composite film with a porous structure, and the material of the substrate layer is selected from at least one of polyethylene, polypropylene, polyethylene terephthalate and polyimide. Specifically, a polypropylene porous film, a polyethylene porous film, a polypropylene non-woven fabric, a polyethylene non-woven fabric, or a polypropylene-polyethylene-polypropylene porous composite film can be selected. The porous structure can improve the heat resistance, oxidation resistance and electrolyte infiltration performance of the isolation membrane, and enhance the adhesion between the isolation membrane and the pole piece.

基材层的至少一个表面上设置有表面处理层，表面处理层可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。A surface treatment layer is provided on at least one surface of the substrate layer. The surface treatment layer may be a polymer layer or an inorganic substance layer, or a layer formed by a mixed polymer and an inorganic substance.

无机物层包括无机颗粒和粘结剂，无机颗粒选自氧化铝、氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙和硫酸钡中的一种或几种的组合。粘结剂选自聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯和聚六氟丙烯中的一种或几种的组合。The inorganic layer includes inorganic particles and a binder. The inorganic particles are selected from alumina, silica, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, One or a combination of yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and barium sulfate. The binder is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, One or a combination of polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene.

聚合物层中包含聚合物，聚合物的材料选自聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯醚、聚偏氟乙烯、聚(偏氟乙烯-六氟丙烯)中的至少一种。The polymer layer contains a polymer, and the material of the polymer is selected from polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polyvinylidene fluoride, poly At least one of (vinylidene fluoride-hexafluoropropylene).

电化学装置Electrochemical device

本申请还提供了一种电化学装置，其包括正极、电解液和负极，所述正极包括正极活性材料层和正极集流体，所述负极包括负极活性材料层和负极集流体，所述负极活性材料层包括根据本申请所述的负极活性材料。The present application also provides an electrochemical device, which includes a positive electrode, an electrolyte, and a negative electrode. The positive electrode includes a positive electrode active material layer and a positive electrode current collector. The negative electrode includes a negative electrode active material layer and a negative electrode current collector. The material layer includes the negative active material according to the present application.

本申请的电化学装置包括发生电化学反应的任何装置，它的具体实例包括所有种类的一次电池、二次电池、燃料电池、太阳能电池或电容器。特别地，该电化学装置是锂二次电池，包括锂金属二次电池、锂离子二次电池、锂聚合物二次电池或锂离子聚合物二次电池。The electrochemical device of the present application includes any device that undergoes an electrochemical reaction, and specific examples thereof include all kinds of primary batteries, secondary batteries, fuel cells, solar cells, or capacitors. In particular, the electrochemical device is a lithium secondary battery, including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery.

电子装置Electronic device

本申请另提供了一种电子装置，其包括根据本申请的电化学装置。The application also provides an electronic device, which includes the electrochemical device according to the application.

本申请的电化学装置的用途没有特别限定，其可用于现有技术中已知的任何电子装置。在一些实施方案中，本申请的电化学装置可用于，但不限于，笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。The use of the electrochemical device of the present application is not particularly limited, and it can be used in any electronic device known in the prior art. In some embodiments, the electrochemical device of the present application can be used in, but not limited to, notebook computers, pen-input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, and headsets. Stereo headsets, video recorders, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notebooks, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power assistance Bicycles, bicycles, lighting equipment, toys, game consoles, clocks, power tools, flashlights, cameras, large household storage batteries and lithium-ion capacitors, etc.

下面以锂离子电池为例并且结合具体的实施例说明锂离子电池的制备，本领域的技术人员将理解，本申请中描述的制备方法仅是实例，其他任何合适的制备方法均在本申请的范围内。The following takes a lithium ion battery as an example and describes the preparation of a lithium ion battery in conjunction with specific examples. Those skilled in the art will understand that the preparation methods described in this application are only examples, and any other suitable preparation methods are described in this application. Within range.

实施例Example

以下说明根据本申请的锂离子电池的实施例和对比例进行性能评估。The following describes the performance evaluation according to the examples and comparative examples of the lithium ion battery of the present application.

一、锂离子电池的制备1. Preparation of Lithium Ion Battery

1、负极活性材料的制备1. Preparation of negative electrode active material

空气气氛下，将酚醛树脂在330度下预氧化，所得固体再经粉碎制粉。置于氩气气氛的管式炉中升温至800度，升温速率为5度/分钟，保温3小时，在此过程中硬碳前驱体发生裂解反应，生成硬碳材料。在预氧化前，通过加入硅烷偶联剂(例如，v一氯丙基三乙氧基硅烷)可实现使得其表面形成带电基团。将2kg硬碳分散到乙醇中，得到第一溶液。将0.05mol柠檬酸溶于1mL异丙醇中，待完全溶解后，加入1.5mol钛酸丁酯，在1000rpm下搅拌至少30分钟，经水系滤膜过滤后，得到二氧化钛溶胶-凝胶溶液。将含金属的纳米粒子(金纳米粒子、银纳米粒子或金银合金纳米粒子)按快速注入到第二氧化钛溶胶-凝胶溶液中，得到第二溶液。将1000mL第二溶液加入第一溶液中，在50℃下持续搅拌90分钟，得到第三溶液。然后，将王水分散到第三溶液中，洗脱含金属的纳米粒子(金纳米粒子、银纳米粒子或金银合金纳米粒子)，释放其所占空间形成孔道。将所得溶液静置180分钟，在70℃下初步干燥10小时以去除溶剂，之后在氩气气氛下经1000℃热处理除杂质，得到负极活性材料。In an air atmosphere, the phenolic resin is pre-oxidized at 330 degrees, and the solid obtained is crushed and powdered. The temperature is raised to 800 degrees in a tube furnace in an argon atmosphere at a heating rate of 5 degrees per minute, and the temperature is kept for 3 hours. During this process, the hard carbon precursor undergoes a cracking reaction to produce hard carbon materials. Before pre-oxidation, a silane coupling agent (for example, v-chloropropyltriethoxysilane) can be added to form charged groups on the surface. Disperse 2 kg of hard carbon in ethanol to obtain the first solution. Dissolve 0.05 mol of citric acid in 1 mL of isopropanol. After it is completely dissolved, add 1.5 mol of butyl titanate, stir at 1000 rpm for at least 30 minutes, and filter through an aqueous membrane to obtain a titanium dioxide sol-gel solution. The metal-containing nanoparticles (gold nanoparticles, silver nanoparticles or gold-silver alloy nanoparticles) are quickly injected into the second titanium oxide sol-gel solution to obtain a second solution. 1000 mL of the second solution was added to the first solution, and stirring was continued at 50° C. for 90 minutes to obtain the third solution. Then, aqua regia is dispersed in the third solution to elute metal-containing nanoparticles (gold nanoparticles, silver nanoparticles or gold-silver alloy nanoparticles), and release the space occupied by them to form pores. The resulting solution was allowed to stand for 180 minutes, and was preliminarily dried at 70° C. for 10 hours to remove the solvent, and then heat-treated at 1000° C. in an argon atmosphere to remove impurities to obtain a negative electrode active material.

带电基团可通过树脂的选择、硅烷偶联剂的选择等方式控制，只要能够实现即可。The charged group can be controlled by the selection of the resin, the selection of the silane coupling agent, etc., as long as it can be realized.

2、负极的制备2. Preparation of negative electrode

将上述制备的负极活性材料、丁苯橡胶(SBR)和羧甲基纤维素钠(CMC)按照重量比97∶1∶2在适量的去离子水中充分搅拌混合，使其形成均匀的负极浆料，其中负极浆料的固含量为54wt％。将此浆料涂覆于负极集流体(铜箔)上，在85℃下烘干，然后经过冷压、裁片、分切后，在120℃的真空条件下干燥12小时，得到负极。The negative active material, styrene butadiene rubber (SBR) and sodium carboxymethyl cellulose (CMC) prepared above are thoroughly stirred and mixed in an appropriate amount of deionized water at a weight ratio of 97:1:2 to form a uniform negative electrode slurry , Wherein the solid content of the negative electrode slurry is 54wt%. This slurry was coated on a negative electrode current collector (copper foil), dried at 85°C, and then cold pressed, cut into pieces, and cut, and dried under vacuum conditions at 120°C for 12 hours to obtain a negative electrode.

3、正极的制备3. Preparation of positive electrode

将钴酸锂(LiCoO ₂)、导电剂Super P和聚偏二氟乙烯(PVDF)按重量比97∶1.4∶1.6在适量的N-甲基吡咯烷酮(NMP)溶剂中充分搅拌混合，使其形成均匀的正极浆料，其中正极浆料的固含量为72wt％。将此浆料涂覆于正极集流体铝箔上，在85℃下烘干，然后经过冷压、裁片、分切后，在85℃的真空条件下干燥4小时，得到正极。 Mix lithium cobaltate (LiCoO ₂ ), conductive agent Super P and polyvinylidene fluoride (PVDF) in an appropriate amount of N-methylpyrrolidone (NMP) solvent at a weight ratio of 97:1.4:1.6 to make it form Uniform positive electrode slurry, wherein the solid content of the positive electrode slurry is 72 wt%. The slurry was coated on the positive electrode current collector aluminum foil, dried at 85°C, and then cold-pressed, cut into pieces, and cut, and dried under vacuum at 85°C for 4 hours to obtain a positive electrode.

4、电解液的制备4. Preparation of electrolyte

在干燥的氩气气氛手套箱中，将碳酸乙烯酯(EC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)按照质量比为EC∶EMC∶DEC＝30∶50∶20进行混合，接着加入3％的氟代碳酸乙烯酯，1.5％的1，3丙烷磺内酯，溶解并充分搅拌后加入锂盐LiPF ₆，混合均匀后获得电解液，其中LiPF ₆的浓度为1mol/L。 In a dry argon atmosphere glove box, mix ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a mass ratio of EC:EMC:DEC=30:50:20 , Then add 3% fluoroethylene carbonate, 1.5% 1,3 propane sultone, dissolve and stir well, add lithium salt LiPF ₆ , and mix well to obtain electrolyte, in which _{the concentration of LiPF 6} is 1mol/L .

5、隔离膜的制备5. Preparation of isolation membrane

以7μm厚的聚乙烯(PE)多孔聚合物薄膜作为隔离膜。A polyethylene (PE) porous polymer film with a thickness of 7 μm was used as the separator.

6、锂离子电池的制备6. Preparation of Lithium Ion Battery

将正极、隔离膜、负极按顺序叠好，使隔离膜处于正极和负极之间起到隔离的作用，然后卷绕得到、焊接极耳、置于外包装箔铝塑膜中，注入上述制备好的电解液，经过真空封装、静置、化成、整形、容量测试等工序，获得软包锂离子电池。Lay the positive electrode, separator film, and negative electrode in order, so that the separator film is located between the positive electrode and the negative electrode for isolation, and then wind up, weld the tabs, place it in the outer packaging foil aluminum-plastic film, and inject the above-prepared The electrolyte is vacuum packaged, standing, forming, shaping, capacity testing and other processes to obtain a soft-packed lithium-ion battery.

二、测试方法2. Test method

1、锂离子电池的循环容量保持率的测试方法1. Test method for the cycle capacity retention rate of lithium-ion batteries

在25℃的环境中，将锂离子电池以0.7C恒流充电至电压4.4V，然后恒压充电；以1C恒流放电至电压3V，此记为一个循环，并记录首次循环的放电容量。进行200次的循环，记录第200次循环的放电容量。通过下式计算锂离子电池的循环容量保持率：In an environment of 25°C, charge the lithium-ion battery at a constant current of 0.7C to a voltage of 4.4V, and then charge at a constant voltage; discharge at a constant current of 1C to a voltage of 3V, this is recorded as a cycle, and the discharge capacity of the first cycle is recorded. Perform 200 cycles, and record the discharge capacity of the 200th cycle. Calculate the cycle capacity retention rate of lithium-ion batteries by the following formula:

循环容量保持率＝(第200次循环的放电容量/首次循环的放电容量)×100％。Cycle capacity retention ratio=(discharge capacity at the 200th cycle/discharge capacity at the first cycle)×100%.

每个实施例或对比例测试5个样品，取平均值。Five samples were tested for each example or comparative example, and the average value was taken.

2、锂离子电池的热冲击承受时间的测试方法2. Test method of thermal shock endurance time of lithium ion battery

使锂离子电池达到满充状态，并将其置于150℃的高温箱中，将锂离子电池开始出现火焰的时间记为热冲击承受时间。每个实施例或对比例测试5个样品，取平均值。The lithium-ion battery is fully charged and placed in a high temperature box at 150°C. The time when the lithium-ion battery starts to appear flame is recorded as the thermal shock endurance time. Five samples were tested for each example or comparative example, and the average value was taken.

3、锂离子电池的过充测试方法3. Overcharge test method of lithium ion battery

在10V下，使锂离子电池在1C倍率的电流密度下过充，测试锂离子电池的表面温度。每个实施例或对比例测试5个样品，取平均值。Under 10V, the lithium-ion battery was overcharged at a current density of 1C, and the surface temperature of the lithium-ion battery was tested. Five samples were tested for each example or comparative example, and the average value was taken.

4、锂离子电池的穿钉测试方法4. Nail penetration test method for lithium-ion batteries

将锂离子电池置于25℃恒温箱中，静置30分钟，使锂离子电池达到恒温。将达到恒温的锂离子电池以0.5C恒流充电至电压为4.4V，然后以4.4V恒压充电至电流为0.025C。将满充锂离子电池转移至穿钉测试机上，保持测试环境温度25℃±2℃，用直径为4mm的钢钉，以30mm/s的速度匀速穿过锂离子电池中心，保留300秒。测试锂离子电池的表面温度。每个实施例或对比例测试5个样品，取平均值。Place the lithium-ion battery in a thermostat at 25°C and let it stand for 30 minutes to bring the lithium-ion battery to a constant temperature. The lithium ion battery that has reached a constant temperature is charged at a constant current of 0.5C to a voltage of 4.4V, and then charged at a constant voltage of 4.4V to a current of 0.025C. Transfer the fully charged lithium ion battery to the nail piercing tester, keep the test environment at 25°C±2°C, use a steel nail with a diameter of 4mm to pass through the center of the lithium ion battery at a speed of 30mm/s at a constant speed, and keep it for 300 seconds. Test the surface temperature of the lithium ion battery. Five samples were tested for each example or comparative example, and the average value was taken.

5、锂离子电池的撞击测试方法5. Impact test method of lithium ion battery

在25℃下，将锂离子电池以0.5C恒流充电至电压为4.3V，之后以4.3V恒压充电至电流为0.05C，采用UL1642测试标准，其中，重锤质量为9.8kg、直径为15.8mm、下落高度为61±2.5cm，对锂离子电池进行撞击测试。测试锂离子电池的表面温度。每个实施例或对比例测试5个样品，取平均值。At 25℃, the lithium-ion battery is charged at a constant current of 0.5C to a voltage of 4.3V, and then charged at a constant voltage of 4.3V to a current of 0.05C. The UL1642 test standard is adopted. The weight of the weight is 9.8kg and the diameter is 15.8mm, drop height of 61±2.5cm, impact test on lithium ion battery. Test the surface temperature of the lithium ion battery. Five samples were tested for each example or comparative example, and the average value was taken.

6、负极活性材料的比表面积的测试方法6. Test method for specific surface area of negative electrode active material

采用GB/T 19587-2017标准，采用测试仪器Tristar II 3020M，用氦氮混合气(氦气∶氮气＝4∶1，氦气为载气，氮气为吸附气体)流过被测样品，并利用氮气在液氮温度下的吸附及脱液氮环境下的脱附，精确测量氮气前后的比例变化。利用固体标样参比法座位测试软件分析模型，计算出样品的比表面积。Adopt GB/T 19587-2017 standard, use test instrument Tristar II 3020M, use helium-nitrogen mixture (helium:nitrogen=4:1, helium as carrier gas, nitrogen as adsorption gas) flow through the tested sample, and use The adsorption of nitrogen at the temperature of liquid nitrogen and the desorption under the environment of desorption of liquid nitrogen can accurately measure the ratio change before and after nitrogen. Use the solid standard sample reference method seat test software to analyze the model and calculate the specific surface area of the sample.

7、负极活性材料中的金属元素的测试方法7. Test method of metal elements in negative electrode active material

根据EPA 6010D-2014标准，采用测试仪器PE7000DV，用硝酸/氢氟酸和盐酸分解样品，高氯酸冒烟驱尽硅和氟，盐酸溶解盐类，试液稀释至规定体积。用电感耦合等离子体发射光谱仪测量溶液中分析元素的发射光谱强度。According to the EPA 6010D-2014 standard, the test instrument PE7000DV is used to decompose the sample with nitric acid/hydrofluoric acid and hydrochloric acid. Perchloric acid emits smoke to drive out silicon and fluorine, hydrochloric acid dissolves salts, and the test solution is diluted to the specified volume. The inductively coupled plasma emission spectrometer was used to measure the intensity of the emission spectra of the analytical elements in the solution.

8、负极活性材料层的孔隙率的测试方法8. Test method for porosity of negative electrode active material layer

根据《铁矿石表观密度、真密度和孔隙率的测定GB/T 24586-2009》标准，采用测试仪器AccuPyc II 1340，通过质量体积法计算。每个样品至少测量至少3个不同位置的体积，取平均值。通过电子天平测量样品的质量，每个样品测量至少3次，取平均值。通过下式计算负极活性材料层的孔隙率：According to the "Determination of Apparent Density, True Density and Porosity of Iron Ore GB/T 24586-2009" standard, using the testing instrument AccuPyc II 1340, calculated by the mass volume method. Measure the volume of at least 3 different positions for each sample and take the average value. Measure the quality of the samples with an electronic balance, measure each sample at least 3 times, and take the average value. The porosity of the negative electrode active material layer is calculated by the following formula:

孔隙率＝m/V×Ps×100％，Porosity=m/V×Ps×100%,

其中：m为测试得到的平均质量(g)，V测试得到的平均体积(cm ³)，Ps为样品的真密度(g/cm ³)。 Where: m is the average mass (g) obtained by the test, the average volume (cm ³ ) obtained by the V test, and Ps is the true density of the sample (g/cm ³ ).

9、负极活性材料的飞行时间二次离子质谱测试方法9. Time-of-flight secondary ion mass spectrometry test method for negative electrode active materials

采用型号为PHI TRIFT II的离子质谱仪进行测试。The ion mass spectrometer model PHI TRIFT II is used for testing.

三、测试结果Three, test results

表1展示了锂离子电池中使用的负极活性材料的保护层对锂离子电池的循环性能和安全性的影响。Table 1 shows the influence of the protective layer of the negative electrode active material used in the lithium ion battery on the cycle performance and safety of the lithium ion battery.

表1Table 1

①表示以下带正电基团：C ₂H ₃ ⁺、Si ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₇ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、SiC ₃H ₉ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₃O ₂C ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺、Si ₄O ₄C ₇H ₂₁ ⁺。 ① represents the following positively charged groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₃ O ₂ C ₅ H ₁₅ ⁺ , Si ₃ O ₃ C ₅ H ₁₅ ⁺ , Si ₄ O ₄ C ₇ H ₂₁ ⁺ .

②表示以下带正电基团：C ₂H ₃ ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₅ ⁺、C ₄H ₅ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、C ₆H ₅ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺。 ② means the following positively charged groups: C ₂ H ₃ ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₅ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ .

③表示以下带正电基团：C ₂H ₃ ⁺、Si ⁺、C ₃H ₅ ⁺、C ₃H ₇ ⁺、C ₄H ₅ ⁺、C ₄H ₉ ⁺、SiC ₃H ₉ ⁺、C ₆H ₅ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₂OC ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺、Si ₃O ₂C ₇H ₂₁ ⁺。 ③ represents the following positively charged groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₃ H ₅ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₉ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₂ OC ₅ H ₁₅ ⁺ , Si ₃ O ₃ C ₅ H ₁₅ ⁺ , Si ₃ O ₂ C ₇ H ₂₁ ⁺ .

A表示以下带负电基团：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、SiO ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、C ₅H ₇N ^-、C ₁₄H ₂₁O ^-、Si ₃O ₄C ₅H ₁₅ ^-。 A denotes the negatively charged ^{^{group: CH -, O -, CN}} -, C 3 H 2 -, C 4 H -, C 2 H 3 O 2 -, SiO 2 -, C 4 H 7 O -, C 3 H _{_{^{_{9 N 2 -, C 5 H}}}} 7 N -, C 14 H 21 O -, Si 3 O 4 C 5 H 15 -.

B表示以下带负电基团：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、PO ₃ ^-、C ₅H ₇N ^-、、C ₁₄H ₂₁O ^-。 B denotes the negatively charged ^{^{group: CH -, O -, CN}} -, C 3 H 2 -, C 2 HO -, C 4 H -, C 2 H 3 O 2 -, C 4 H 7 O -, C 3 _{_{^{_{H 9 N 2 -, PO 3}}}} -, C 5 H 7 N - ,, C 14 H 21 O -.

C表示以下带负电基团：CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₂H ₃O ₂ ^-、PO ₂ ^-、C ₄H ₇O ^-、SiO ₂CH ₃ ^-、C ₅H ₇N ^-、Si ₂O ₃C ₃H ₉ ^-、C ₁₄H ₂₁O ^-、Si ₃O ₄C ₅H ₁₅ ^-。 C represents the negatively charged ^{^{groups: CH -, O -, CN}} -, C 3 H 2 -, C 2 HO -, C 2 H 3 O 2 -, PO 2 -, C 4 H 7 O -, SiO 2 CH _{^{_{_{3 -, C 5 H 7 N}}}} -, Si 2 O 3 C 3 H 9 -, C 14 H 21 O -, Si 3 O 4 C 5 H 15 -.

结果表明，相比于对比例1，当负极活性材料具有保护层，且采用飞行时间二次离子质谱测试，所述保护层具有①、②或③组带负电基团和/或具有A、B或C组带正电基团)，锂离子电池的循环容量保持率显著升高、热冲击承受时间显著延长并且在过充测试、穿钉测试和撞击测试中的表面温度显著降低和能量密度显著升高，即显著改善了锂离子电池的循环性能和安全性。当保护层的厚度在1nm至200nm的范围内时，可进一步改善锂离子电池的循环性能和安全性。The results show that, compared to Comparative Example 1, when the negative electrode active material has a protective layer and the time-of-flight secondary ion mass spectrometry test is used, the protective layer has negatively charged groups ①, ② or ③ and/or has A, B Or C group positively charged group), the cycle capacity retention rate of the lithium ion battery is significantly increased, the thermal shock withstand time is significantly extended, and the surface temperature and energy density are significantly reduced in the overcharge test, nail penetration test and impact test. Increased significantly improves the cycle performance and safety of lithium-ion batteries. When the thickness of the protective layer is in the range of 1 nm to 200 nm, the cycle performance and safety of the lithium ion battery can be further improved.

表2展示了负极活性材料的材料、结构和性质对锂离子电池的循环性能和安全性的影响。除表2中所列参数以外，实施例12-34与实施例2的其它条件一致。Table 2 shows the influence of the material, structure and properties of the negative active material on the cycle performance and safety of lithium-ion batteries. Except for the parameters listed in Table 2, the other conditions of Examples 12-34 are consistent with those of Example 2.

结果表明，当负极活性材料包含小于0.1wt％的一种或多种金属元素和/或50ppm至200ppm的一种或多种非金属元素时，可进一步提升锂离子电池的循环容量保持率、延长热冲击承受时间并且降低在过充测试、穿钉测试和撞击测试中的表面温度，即显著改善了锂离子电池的循环性能和安全性。当负极活性材料包含孔道且该孔道包含金属和/或非金属元素时，有助于进一步改善锂离子电池的循环性能和安全性。当负极活性材料包含不大于1wt％的磷元素时，可进一步改善锂离子电池的循环性能和安全性。当负极活性材料的比表面积在0.7m ²/g至100m ²/g的范围内、负极活性材料层的孔隙率在15％至45％的范围内和/或负极活性材料层相对电解液的接触角在80°至96°的范围内时，有助于进一步改善锂离子电池的循环性能和安全性。 The results show that when the negative electrode active material contains less than 0.1 wt% of one or more metal elements and/or 50 ppm to 200 ppm of one or more non-metal elements, the cycle capacity retention rate of the lithium ion battery can be further improved, and the Thermal shock withstand time and reduce the surface temperature in the overcharge test, nail penetration test and impact test, which significantly improves the cycle performance and safety of lithium-ion batteries. When the negative electrode active material contains pores and the pores contain metal and/or non-metal elements, it helps to further improve the cycle performance and safety of the lithium ion battery. When the negative electrode active material contains no more than 1 wt% of the phosphorus element, the cycle performance and safety of the lithium ion battery can be further improved. When the specific surface area of the negative electrode active material is in the range of 0.7 m ² /g to 100 m ² /g, the porosity of the negative electrode active material layer is in the range of 15% to 45%, and/or the negative electrode active material layer is in contact with the electrolyte When the angle is in the range of 80° to 96°, it helps to further improve the cycle performance and safety of the lithium-ion battery.

提升锂离子电池循环性能同时保证其安全性有助于拓展锂离子电池的应用领域，为其发展提供了广阔空间。Improving the cycle performance of lithium-ion batteries while ensuring their safety will help expand the application fields of lithium-ion batteries and provide a broad space for their development.

整个说明书中对“实施例”、“部分实施例”、“一个实施例”、“另一举例”、“举例”、“具体举例”或“部分举例”的引用，其所代表的意思是在本申请中的至少一个实施例或举例包含了该实施例或举例中所描述的特定特征、结构、材料或特性。因此，在整个说明书中的各处所出现的描述，例如：“在一些实施方案中”、“在实施例中”、“在一个实施例中”、“在另一个举例中”，“在一个举例中”、“在特定举例中”或“举例”，其不必然是引用本申请中的相同的实施例或示例。此外，本文中的特定特征、结构、材料或特性可以以任何合适的方式在一个或多个实施例或举例中结合。References to "embodiments", "partial examples", "one embodiment", "another example", "examples", "specific examples" or "partial examples" throughout the specification mean that At least one embodiment or example in this application includes the specific feature, structure, material, or characteristic described in the embodiment or example. Therefore, descriptions appearing in various places throughout the specification, such as: "in some embodiments", "in an embodiment", "in one example", "in another example", "in an example "In", "in a specific example" or "exemplary", which are not necessarily quoting the same embodiment or example in this application. In addition, the specific features, structures, materials or characteristics herein can be combined in one or more embodiments or examples in any suitable manner.

尽管已经演示和描述了说明性实施例，本领域技术人员应该理解上述实施例不能被解释为对本申请的限制，并且可以在不脱离本申请的精神、原理及范围的情况下对实施例进行改变，替代和修改。Although illustrative embodiments have been demonstrated and described, those skilled in the art should understand that the above-mentioned embodiments should not be construed as limiting the present application, and the embodiments can be changed without departing from the spirit, principle, and scope of the present application , Substitution and modification.

Claims

一种负极活性材料，其包括负极活性物质和在所述负极活性物质的表面的保护层，其中采用飞行时间二次离子质谱测试，所述保护层包括以下带电基团中的至少一种：C ₂H ₃ ⁺、Si ⁺、C ₂H ₅ ⁺、C ₃H ₃ ⁺、C ₃H ₅ ⁺、C ₃H ₇ ⁺、C ₄H ₅ ⁺、C ₄H ₇ ⁺、C ₄H ₉ ⁺、C ₅H ₇ ⁺、SiC ₃H ₉ ⁺、C ₆H ₅ ⁺、C ₆H ₇ ⁺、C ₆H ₉ ⁺、C ₆H ₁₁ ⁺、C ₆H ₁₃ ⁺、C ₇H ₇ ⁺、C ₇H ₁₁ ⁺、C ₇H ₁₃ ⁺、C ₈H ₁₃ ⁺、C ₈H ₁₁N ₂ ⁺、Si ₂OC ₅H ₁₅ ⁺、Si ₃O ₂C ₅H ₁₅ ⁺、Si ₃O ₃C ₅H ₁₅ ⁺、Si ₃O ₂C ₇H ₂₁ ⁺、Si ₄O ₄C ₇H ₂₁ ⁺、CH ^-、O ^-、CN ^-、C ₃H ₂ ^-、C ₂HO ^-、C ₄H ^-、C ₂H ₃O ₂ ^-、SiO ₂ ^-、PO ₂ ^-、C ₄H ₇O ^-、C ₃H ₉N ₂ ^-、SiO ₂CH ₃ ^-、PO ₃ ^-、C ₅H ₇N ^-、Si ₂O ₃C ₃H ₉ ^-、C ₁₄H ₂₁O ^-或Si ₃O ₄C ₅H ₁₅ ^-。 A negative electrode active material, comprising a negative electrode active material and a protective layer on the surface of the negative electrode active material, wherein a time-of-flight secondary ion mass spectrometry test is adopted, and the protective layer includes at least one of the following charged groups: C ₂ H ₃ ⁺ , Si ⁺ , C ₂ H ₅ ⁺ , C ₃ H ₃ ⁺ , C ₃ H ₅ ⁺ , C ₃ H ₇ ⁺ , C ₄ H ₅ ⁺ , C ₄ H ₇ ⁺ , C ₄ H ₉ ⁺ , C ₅ H ₇ ⁺ , SiC ₃ H ₉ ⁺ , C ₆ H ₅ ⁺ , C ₆ H ₇ ⁺ , C ₆ H ₉ ⁺ , C ₆ H ₁₁ ⁺ , C ₆ H ₁₃ ⁺ , C ₇ H ₇ ⁺ , C ₇ H ₁₁ ⁺ , C ₇ H ₁₃ ⁺ , C ₈ H ₁₃ ⁺ , C ₈ H ₁₁ N ₂ ⁺ , Si ₂ OC ₅ H ₁₅ ⁺ , Si ₃ O ₂ C ₅ H ₁₅ ⁺ , Si ₃ O ₃ C ₅ H ₁₅ ^{_{_{_{+, Si 3 O 2 C 7}}}} H 21 +, Si 4 O 4 C 7 H 21 +, CH -, O -, CN -, C 3 H 2 -, C 2 HO -, C 4 H -, C 2 H _{_{^{_{^{3 O 2 -, SiO 2 -}}}}} , PO 2 -, C 4 H 7 O -, C 3 H 9 N 2 -, SiO 2 CH 3 -, PO 3 -, C 5 H 7 N -, Si 2 O 3 C _{_{^{_{3 H 9 -, C 14 H}}}} 21 O - or _{_{_{_{Si 3 O 4 C 5 H 15}}}} -.
根据权利要求1所述的负极活性材料，其中所述保护层的厚度为1nm至200nm。The negative active material of claim 1, wherein the protective layer has a thickness of 1 nm to 200 nm.
根据权利要求1所述的负极活性材料，其中所述负极活性材料还包含金属元素，所述金属元素包含金、银、铂、锆、锌、镁、钙、钡、钒、铁或铝中的至少一种，基于所述负极活性材料的总重量，所述金属元素的含量小于0.1wt％。The anode active material according to claim 1, wherein the anode active material further comprises a metal element, and the metal element comprises gold, silver, platinum, zirconium, zinc, magnesium, calcium, barium, vanadium, iron, or aluminum. At least one, based on the total weight of the negative active material, the content of the metal element is less than 0.1 wt%.
根据权利要求3所述的负极活性材料，其中所述负极活性材料进一步包含非金属元素，所述非金属元素包括硼、砷或硒中的至少一种，基于所述负极活性材料的总重量，所述非金属元素的含量为50ppm至200ppm。4. The negative active material of claim 3, wherein the negative active material further comprises a non-metallic element including at least one of boron, arsenic, or selenium, based on the total weight of the negative active material, The content of the non-metal elements is 50 ppm to 200 ppm.
根据权利要求3所述的负极活性材料，其中所述负极活性材料包含孔道，所述孔道的内壁包含所述金属元素。The negative active material according to claim 3, wherein the negative active material includes pores, and inner walls of the pores include the metal element.
根据权利要求1所述的负极活性材料，其中所述负极活性材料包含磷元素，基于所述负极活性材料的总重量计，所述磷元素的含量不大于1wt％。The negative active material according to claim 1, wherein the negative active material contains phosphorus element, and the content of the phosphorus element is not more than 1 wt% based on the total weight of the negative active material.
根据权利要求1所述的负极活性材料，其中所述负极活性材料的中值粒径为5μm至20μm；所述负极活性材料的比表面积为0.7m ²/g至100m ²/g。 The negative active material of claim 1, wherein the median particle size of the negative active material is 5 μm to 20 μm; the specific surface area of the negative active material is 0.7 m ² /g to 100 m ² /g.
一种电化学装置，其包括正极、电解液和负极，所述正极包括正极活性材料层和正极集流体，所述负极包括负极活性材料层和负极集流体，所述负极活性材料层包括根据权利要求1-7中任一权利要求所述的负极活性材料。An electrochemical device comprising a positive electrode, an electrolyte and a negative electrode, the positive electrode comprising a positive electrode active material layer and a positive electrode current collector, the negative electrode comprising a negative electrode active material layer and a negative electrode current collector, the negative electrode active material layer comprising The negative electrode active material according to any one of claims 1-7.
根据权利要求8所述的电化学装置，其中所述负极活性材料层的孔隙率为15％至45％。The electrochemical device according to claim 8, wherein the porosity of the anode active material layer is 15% to 45%.
根据权利要求9所述的电化学装置，其中所述负极活性材料层相对所述电解液的接触角为80°至96°。The electrochemical device according to claim 9, wherein the contact angle of the anode active material layer with respect to the electrolyte is 80° to 96°.
一种电子装置，其包括根据权利要求8-10中任一项权利要求所述的电化学装置。An electronic device comprising the electrochemical device according to any one of claims 8-10.