WO2023056635A1

WO2023056635A1 - Positive electrode material for lithium-ion battery, preparation method therefor, and application thereof

Info

Publication number: WO2023056635A1
Application number: PCT/CN2021/122866
Authority: WO
Inventors: 潘锋; 赵庆贺; 易浩聪; 任恒宇; 林海
Original assignee: 北京大学深圳研究生院
Priority date: 2021-10-09
Filing date: 2021-10-09
Publication date: 2023-04-13
Also published as: CN115244735A

Abstract

The present application discloses a positive electrode material for a lithium-ion battery, a preparation method therefor, and an application thereof. According to the positive electrode material for a lithium-ion battery of the present application, a surface interface of a crystal structure thereof is provided with a high-electron-conductivity inorganic compound layer which is electrically conductive and lithium-conductive and does not participate in an electrochemical side reaction or chemical side reaction on an interface between an electrode and a solution. According to the positive electrode material for a lithium-ion battery of the present application, the inorganic compound layer thereof can block a transition metal from an electrolyte, thereby inhibiting the catalytic decomposition effect of transition metal ions on the electrolyte under high voltage, and reducing the side reaction on the surface of the electrode in a cyclic process; moreover, Li+ embedding kinetics is increased by reducing polarization of the electrode, such that the positive electrode material for a lithium-ion battery of the present application also has the advantages of being high in capacity, high in rate, good in cyclic stability and the like under high voltage. In addition, the preparation method for the positive electrode material for a lithium-ion battery of the present application is simple, and is easy to perform large-scale industrial production.

Description

一种锂离子电池正极材料及其制备方法和应用A kind of positive electrode material of lithium ion battery and its preparation method and application

技术领域technical field

本申请涉及电池正极材料领域，特别是涉及一种锂离子电池正极材料及其制备方法和应用。The present application relates to the field of battery positive electrode materials, in particular to a lithium ion battery positive electrode material and its preparation method and application.

背景技术Background technique

自锂离子电池产业化以来，其安全性、循环寿命、能量密度和功率密度等重要指标均与锂电池电极材料的性能密切相关。由于负极材料的容量远高于正极，正极材料性能的优劣成为进一步提升锂离子电池性能的主要限制因素，因此产业界和学界均将研发重点放在提升正极材料性能方面。无机类正极材料包括，以LiCoO ₂、LiNiO ₂、LiMnO ₂等为代表的层状过渡族金属氧化物，以LiMn ₂O ₄为代表的尖晶石结构材料和以LiFePO ₄为代表的橄榄石类氧化物，是目前产业应用比较成熟的材料体系。然而，随着科技进步和市场需求迭代，迫切需要对当前材料体系进行改性优化和探索新材料开发体系。 Since the industrialization of lithium-ion batteries, important indicators such as safety, cycle life, energy density, and power density are closely related to the performance of lithium-ion battery electrode materials. Since the capacity of the negative electrode material is much higher than that of the positive electrode, the performance of the positive electrode material has become the main limiting factor to further improve the performance of lithium-ion batteries. Therefore, both the industry and the academic circles focus on improving the performance of the positive electrode material. Inorganic positive electrode materials include layered transition metal oxides represented by LiCoO ₂ , LiNiO ₂ , LiMnO _{2 ,} etc., spinel structure materials represented by LiMn ₂ O ₄ and olivine represented by LiFePO ₄ Oxide is a relatively mature material system for industrial applications. However, with the advancement of science and technology and the iteration of market demand, it is urgent to modify and optimize the current material system and explore new material development systems.

目前，无机层状结构类型材料体系占据锂离子电池的绝大部分市场，但不同层状正极材料体系的应用特点并不相同。如，LiCoO ₂材料产品成熟度高，性能稳定等优势使其在3C电子产品领域被广泛应用；三元层状材料，包括NMC、NCA等，在电动汽车等动力电池领域被广泛应用。针对LiCoO ₂材料的研究，通过提高工作电压，获得材料晶格中更高的Li ⁺利用率，进一步逼近其极限容量和能量密度，是近年来研究的热点。以前，LiCoO ₂材料的充电电压没有超过4.2V vs.Li/Li ⁺，容量仅能发挥理论容量(274mAh g ^-1)的一半。通过提高工作电压，可获得更高能量密度，如在4.5V vs.Li/Li ⁺的充电截止电压下，LiCoO ₂材料在1C倍率下，初始放电容量可提升至190mAh g ^-1和700Wh Kg ^-1。但高工作电压下，LiCoO ₂材料出现容量衰减速率快和倍率性能降低的问题，这与高充电电压下电解液分解、电极材料结构坍塌和晶格中氧损失、电极材料/电解液界面处CEI膜层快速积累等密切相关。同时，针对三元层状材料，包括NMC、NCA等，在高电压下也是同样存在类似问题。 At present, the inorganic layered structure type material system occupies most of the lithium-ion battery market, but the application characteristics of different layered cathode material systems are not the same. For example, the advantages of LiCoO ₂ material product maturity and stable performance make it widely used in the field of 3C electronic products; ternary layered materials, including NMC, NCA, etc., are widely used in the field of power batteries such as electric vehicles. For the research of _LiCoO2 materials, by increasing the working voltage, obtaining higher Li ⁺ utilization rate in the material lattice, and further approaching its limit capacity and energy density, it is a research hotspot in recent years. Previously, the charging voltage of LiCoO ₂ material did not exceed 4.2V vs. Li/Li ⁺ , and the capacity could only play half of the theoretical capacity (274mAh g ^-1 ). By increasing the operating voltage, higher energy density can be obtained. For example, at the charge cut-off voltage of 4.5V vs. Li/Li ⁺ , the initial discharge capacity of LiCoO ₂ material can be increased to 190mAh g ^-1 and 700Wh Kg ^-1 at 1C rate ¹ . However, under high operating voltage, _LiCoO2 material has the problems of fast capacity decay rate and low rate performance, which is related to the decomposition of electrolyte, the collapse of electrode material structure and the loss of oxygen in the lattice, and the CEI at the electrode material/electrolyte interface. It is closely related to the rapid accumulation of film layers. At the same time, for ternary layered materials, including NMC, NCA, etc., similar problems also exist under high voltage.

作为一种有效的改性手段，通过表面包覆对材料进行优化处理，是学界和产业界比较认可的一种方法。包覆处理不仅能稳固材料结构，优化材料形貌和改善界面，助力界面离子传输过程，而且包覆后表界面物化性质改变，能有效缓解副反应，提高活性材料在高电压下的稳定性，降低电池热效应。表面包覆能有效拓宽活性材料的工作电压窗口，极大的改善和优化材料的能量密度。As an effective means of modification, optimizing materials through surface coating is a relatively recognized method in academia and industry. Coating treatment can not only stabilize the material structure, optimize the material morphology and improve the interface, and facilitate the interfacial ion transport process, but also change the physical and chemical properties of the surface and interface after coating, which can effectively alleviate side reactions and improve the stability of active materials under high voltage. Reduce battery thermal effect. Surface coating can effectively broaden the working voltage window of active materials, greatly improving and optimizing the energy density of materials.

目前来看对层状材料的表面包覆修饰，主要的研究热点集中在具有较大禁带宽度的氧化物，如Al ₂O ₃、ZrO ₂、TiO ₂和ZnO等，或者一些固态电解质如Li ₃PO ₃、LiPON、Li ₄Ti ₅O ₁₂等。这些表面包覆层普遍具有一定的离子电导和高的电化学稳定性，但电子电导率偏低，这对增强层状材料电极的界面动力学不利。 At present, the surface coating modification of layered materials mainly focuses on oxides with large band gaps, such as Al ₂ O ₃ , ZrO ₂ , TiO ₂ and ZnO, or some solid electrolytes such as Li ₃ PO ₃ , LiPON, Li ₄ Ti ₅ O ₁₂ etc. These surface coatings generally have certain ionic conductivity and high electrochemical stability, but low electronic conductivity, which is unfavorable for enhancing the interfacial dynamics of layered material electrodes.

虽然人们从提高离子电导和界面稳定性的角度，对表面包覆层进行了较多研究；但少有人通过提高表面包覆层的电子电导的角度来对层状正极材料进行优化。也就是说，如何提高或优化层状正极材料本身而非包覆层的电子电导是本领域的研究重点和难点。Although people have done a lot of research on the surface coating layer from the perspective of improving ionic conductance and interface stability; but few people have optimized the layered cathode material from the perspective of improving the electronic conductivity of the surface coating layer. That is to say, how to improve or optimize the electronic conductance of the layered cathode material itself rather than the coating layer is the focus and difficulty of research in this field.

发明内容Contents of the invention

本申请的目的是提供一种改进的锂离子电池正极材料及其制备方法和应用。The purpose of this application is to provide an improved lithium-ion battery positive electrode material and its preparation method and application.

本申请采用了以下技术方案：The application adopts the following technical solutions:

本申请的一方面公开了一种锂离子电池正极材料，该锂离子电池正极材料的晶体结构的表面界面具有一层导电、导锂，且不参与电极与溶液的界面电化学副反应或化学副反应的高电子电导的无机化合物层。本申请中的副反应是指除锂离子脱嵌反应以外的其它反应。One aspect of the present application discloses a lithium-ion battery positive electrode material. The surface interface of the crystal structure of the lithium-ion battery positive electrode material has a layer of conductivity and lithium conduction, and does not participate in the electrochemical side reaction or chemical side effect of the interface between the electrode and the solution. Reactive high electron conductivity inorganic compound layer. The side reactions in this application refer to other reactions except lithium ion deintercalation reactions.

需要说明的是，不同于传统的表面包覆修饰，本申请着重针对如何提高界面层氧化物的导电性做了创新和改进。本申请主要是通过元素替换/掺杂在晶体结构表面界面引入大量氧空位，形成本申请的无机化合物层，例如，通过掺杂和/或元素替换在氧化铝、氧化锌、氧化钛、氧化铟、氧化锡及氧化锆的晶体结构中人为制造大量氧空位，显著的提高界面处无机化合物层的电子导电性，这对降低电化学过程电极/溶液界面的极化作用显著。同时，这样的无机化合物层能够阻隔过渡金属层与电解液的直接接触，抑制高电压下过渡金属离子对电解液的催化分解作用，降低循环过程中电极表面副反应。因此，本申请的锂离子电池正极材料在高电压下具有高的容量、倍率和循环稳定性。可以理解，本申请是对锂离子电池正极材料的晶体结构的表面界面进行的优化和改进，从而提高了电子电导率，实现了电极性能的优化，并非简单的表面包覆修饰。It should be noted that, unlike the traditional surface coating modification, this application focuses on innovation and improvement on how to improve the conductivity of the interface layer oxide. This application mainly introduces a large number of oxygen vacancies at the surface interface of the crystal structure through element replacement/doping to form the inorganic compound layer of the application, for example, through doping and/or element replacement in aluminum oxide, zinc oxide, titanium oxide, indium oxide A large number of oxygen vacancies are artificially created in the crystal structure of tin oxide, tin oxide and zirconium oxide, which significantly improves the electronic conductivity of the inorganic compound layer at the interface, which has a significant effect on reducing the polarization of the electrode/solution interface in the electrochemical process. At the same time, such an inorganic compound layer can block the direct contact between the transition metal layer and the electrolyte, inhibit the catalytic decomposition of the transition metal ions on the electrolyte under high voltage, and reduce the side reactions on the electrode surface during the cycle. Therefore, the lithium ion battery positive electrode material of the present application has high capacity, rate and cycle stability under high voltage. It can be understood that this application is to optimize and improve the surface interface of the crystal structure of the positive electrode material of lithium-ion batteries, thereby improving the electronic conductivity and realizing the optimization of electrode performance, not a simple surface coating modification.

本申请的一种实现方式中，无机化合物层与体相层状材料存在化学键合。In one implementation of the present application, there is chemical bonding between the inorganic compound layer and the bulk layered material.

本申请的一种实现方式中，无机化合物层由体相层状材料相同晶格外延生长而成。In an implementation manner of the present application, the inorganic compound layer is epitaxially grown from the same crystal lattice of the bulk layered material.

本申请的一种实现方式中，无机化合物层厚度小于或等于5nm。In an implementation manner of the present application, the thickness of the inorganic compound layer is less than or equal to 5 nm.

本申请的一种实现方式中，无机化合物层中含有0.1％-5.0％的氧缺陷，具体包括以下氧化物中的至少一种；In one implementation of the present application, the inorganic compound layer contains 0.1%-5.0% of oxygen defects, specifically including at least one of the following oxides;

(1)部分F替代O的含锂氧氟化物；(1) Lithium oxyfluoride containing part of F substituted for O;

(2)Zn和/或Mg掺杂的氧化铝；(2) Zn and/or Mg doped alumina;

(3)Nb和/或In掺杂的氧化钛；(3) Nb and/or In-doped titanium oxide;

(4)Ca、Mg、B、Y中的至少一种掺杂的氧化锆；(4) Zirconia doped with at least one of Ca, Mg, B, and Y;

(5)Al、B和In中的至少一种掺杂的ZnO；(5) ZnO doped with at least one of Al, B and In;

(6)Zn和/或Al掺杂的SnO ₂； (6) Zn and/or Al doped SnO ₂ ;

(7)Zn和/或Sn掺杂的In ₂O ₃。 (7) Zn and/or Sn doped In ₂ O ₃ .

本申请的一种实现方式中，部分F替代O的含锂氧氟化物的元素成分还包括Al和/或Co。In an implementation manner of the present application, the elemental composition of the lithium oxyfluoride containing part of F substituted for O further includes Al and/or Co.

本申请的一种实现方式中，Zn掺杂的氧化铝为Al ₂O ₃·xZnO，其中，0.01<x<0.10。 In an implementation manner of the present application, the Zn-doped alumina is Al ₂ O ₃ ·xZnO, where 0.01<x<0.10.

本申请的一种实现方式中，Nb掺杂的氧化钛为Nb _xTi _1-xO，In掺杂的氧化钛为In _yTi _1-yO，其中，0.01<x<0.10，0.01<y<0.10。 In one implementation of the present application, the Nb-doped titanium oxide is Nb _x Ti _1-x O, and the In-doped titanium oxide is In _y Ti _1-y O, wherein, 0.01<x<0.10, 0.01<y <0.10.

本申请的一种实现方式中，Ca掺杂的氧化锆为ZrO ₂·xCaO，Mg掺杂的氧化锆为ZrO ₂·yMgO，B掺杂的氧化锆为ZrO ₂·zB ₂O ₃，Y掺杂的氧化锆为ZrO ₂·rY ₂O ₃，其中，0.01<x<0.10，0.01<y<0.10，0.005<z<0.05，0.005<r<0.05。 In one implementation of the present application, the Ca doped zirconia is ZrO ₂ ·xCaO, the Mg doped zirconia is ZrO ₂ ·yMgO, the B doped zirconia is ZrO ₂ ·zB ₂ O ₃ , and the Y doped zirconia is ZrO 2 ·zB 2 O 3 . The mixed zirconia is ZrO ₂ ·rY ₂ O ₃ , wherein, 0.01<x<0.10, 0.01<y<0.10, 0.005<z<0.05, 0.005<r<0.05.

本申请的一种实现方式中，Al掺杂的ZnO为ZnO·xAl ₂O ₃，B掺杂的ZnO为ZnO·yB ₂O ₃，In掺杂的ZnO为ZnO·yIn ₂O ₃，其中0.005<x<0.05，0.005<y<0.05，0.005<z<0.05。 In one implementation of the present application, Al-doped ZnO is ZnO·xAl ₂ O ₃ , B-doped ZnO is ZnO·yB ₂ O ₃ , and In-doped ZnO is ZnO·yIn ₂ O ₃ , where 0.005 <x<0.05, 0.005<y<0.05, 0.005<z<0.05.

本申请的一种实现方式中，Zn掺杂的SnO ₂为SnO ₂·xZnO，Al掺杂的SnO ₂为SnO ₂·yAl ₂O ₃，其中0.01<x<0.10，0.005<y<0.05。 In an implementation manner of the present application, the Zn-doped SnO ₂ is SnO ₂ ·xZnO, and the Al-doped SnO ₂ is SnO ₂ ·yAl ₂ O ₃ , wherein 0.01<x<0.10, 0.005<y<0.05.

本申请的一种实现方式中，Zn掺杂的In ₂O ₃为In ₂O ₃·xZnO，Sn掺杂的In ₂O ₃为In ₂O ₃·ySnO ₂，其中，0.01<x<0.10，0.01<y<0.10。 In one implementation of the present application, Zn-doped In ₂ O ₃ is In ₂ O ₃ ·xZnO, and Sn-doped In ₂ O ₃ is In ₂ O ₃ ·ySnO ₂ , wherein, 0.01<x<0.10, 0.01<y<0.10.

可以理解，本申请的正极材料表界面处无机化合物的具体选择，主要基于如何提高界面层无机化合物的电子电导。本申请中，为了获得高电子电导率的界面无机化合物层，通过元素掺杂/替换的方式，在氧化铝、氧化锌、氧化钛、氧化铟、氧化锡及氧化锆的晶体结构中制造了较多的氧空位缺陷。It can be understood that the specific selection of the inorganic compound at the surface and interface of the positive electrode material in the present application is mainly based on how to improve the electronic conductance of the inorganic compound at the interface layer. In this application, in order to obtain an interfacial inorganic compound layer with high electronic conductivity, a comparatively high-density compound was produced in the crystal structure of aluminum oxide, zinc oxide, titanium oxide, indium oxide, tin oxide, and zirconium oxide by means of element doping/replacement. many oxygen vacancies.

可以理解，本申请中所用的界面无机化合物层的元素组成调控的目的就是更好的服务于提高界面无机化合物的电子电导这个目标。以上具体选择只是本申请的一种实现方式中具体形成的无机化合物层，除了元素掺杂/替换优化的氧化铝、氧化锌、氧化钛、氧化铟、氧化锡及氧化锆，不排除还可以有其他成分组成的无机化合物层。It can be understood that the purpose of adjusting the elemental composition of the interface inorganic compound layer used in this application is to better serve the goal of improving the electron conductance of the interface inorganic compound. The above specific selection is only the inorganic compound layer specifically formed in one implementation mode of the present application. In addition to element doping/replacement optimized aluminum oxide, zinc oxide, titanium oxide, indium oxide, tin oxide and zirconium oxide, it is not excluded that there may also be Inorganic compound layer composed of other components.

本申请的一种实现方式中，锂离子电池正极材料为通式Li _1+xTMO _2+y的层状正极材料，其中，0≤x≤1，0≤y≤1，TM为过渡金属，TM选自Co、Ni、Mn和Al中至少一种。 In one implementation of the present application, the positive electrode material of the lithium ion battery is a layered positive electrode material of the general formula Li _1+x TMO _2+y , wherein, 0≤x≤1, 0≤y≤1, TM is a transition metal, TM is selected from at least one of Co, Ni, Mn and Al.

本申请的一种实现方式中，锂离子电池正极材料为钴酸锂、高镍二元材料、高镍多元材料、富锂锰正极材料中的至少一种；其中，高镍是指镍含量大于或等于50％。本申请中，二元材料和多元材料，是指含镍、钴、锰、铝等中的两种或多种的正极材料；即二元材料就是含其中两种的正极材料；多元材料即含其中两种以上的正极材料。In an implementation of the present application, the positive electrode material of the lithium ion battery is at least one of lithium cobalt oxide, high-nickel binary material, high-nickel multi-component material, and lithium-rich manganese positive electrode material; wherein, high nickel means that the nickel content is greater than Or equal to 50%. In this application, binary materials and multiple materials refer to positive electrode materials containing two or more of nickel, cobalt, manganese, aluminum, etc.; that is, binary materials are positive electrode materials containing two of them; Two or more positive electrode materials.

优选的，锂离子电池正极材料为LiNi _0.8Co _0.1Mn _0.1O ₂、LiNi _0.5Co _0.3Mn _0.2O ₂和LiCoO ₂中的至少一种。 Preferably, the positive electrode material of the lithium ion battery is at least one of LiNi _0.8 Co _0.1 Mn _0.1 O ₂ , LiNi _0.5 Co _0.3 Mn _0.2 O ₂ and LiCoO ₂ .

需要说明的是，过渡金属选自Co、Ni、Mn和Al中至少一种，这些只是比较常见的锂离子电池层状正极材料，不排除还可以是其他的过渡金属。可以理解，以上几种具体的电池层状正极材料只是本申请的一种实现方式中具体制备的几种锂离子电池层状正极材料，不排除还可以是其他的电池层状正极材料。It should be noted that the transition metal is selected from at least one of Co, Ni, Mn and Al, which are relatively common layered positive electrode materials for lithium-ion batteries, and other transition metals are not excluded. It can be understood that the above specific battery layered positive electrode materials are only several kinds of lithium ion battery layered positive electrode materials specifically prepared in an implementation mode of the present application, and other battery layered positive electrode materials are not excluded.

本申请的另一面公开了本申请的锂离子电池正极材料的制备方法，包括对常规锂离子电池正极材料进行以下处理，获得晶体结构的表面界面具有无机化合物层的锂离子电池正极材料：The other side of the present application discloses the preparation method of the positive electrode material of the lithium ion battery of the present application, including carrying out the following treatment on the positive electrode material of the conventional lithium ion battery to obtain the positive electrode material of the lithium ion battery with an inorganic compound layer on the surface interface of the crystal structure:

步骤一，采用以下方法中的至少一种对常规锂离子电池正极材料进行预处理，Step 1, using at least one of the following methods to pretreat conventional lithium-ion battery cathode materials,

(a)固相球磨法，包括将常规锂离子电池正极材料与含Zn、Al、Ca、Mg、Zr、Ti、Y、In、Sn、B和F的至少一种的纳米固体粉料一起进行球磨混料，获得预处理的电池层状正极材料；(a) solid-phase ball milling method, comprising conventional lithium-ion battery cathode material and nano solid powder containing at least one of Zn, Al, Ca, Mg, Zr, Ti, Y, In, Sn, B and F Ball milling and mixing to obtain pretreated battery layered positive electrode materials;

(b)液相溶液预处理，包括将常规锂离子电池正极材料浸泡于含Ti ²⁺、In ³⁺、Sn ⁴⁺、Zn ²⁺、Al ³⁺、Ca ²⁺、Mg ²⁺、Zr ⁴⁺、ZrO ₃ ^2-、F ^-、Y ³⁺和硼酸根中的至少一种的溶液中，液相处理条件为25-90℃处理1-36h，获得预处理的电池层状正极材料； ⁽ ^b ⁾ Liquid ^- phase solution ^pretreatment ^, including ^soaking conventional ^lithium -ion battery cathode materials in In a solution of at least one of ⁺ , ZrO ₃ ^2- , F ^- , Y ³⁺ and borate, the liquid phase treatment condition is 25-90°C for 1-36 hours to obtain a pretreated battery layered positive electrode material;

步骤二，将步骤一获得的预处理的电池层状正极材料，在惰性气氛或还原性气氛下，300-700℃烧结1-24h，自然降温，即获得晶体结构的表面界面具有无机化合物层的锂离子电池正极材料。Step 2: Sinter the pretreated battery layered cathode material obtained in Step 1 at 300-700°C for 1-24 hours in an inert atmosphere or a reducing atmosphere, and cool down naturally to obtain a crystal structure with an inorganic compound layer on the surface interface Lithium-ion battery cathode material.

需要说明的是，本申请中，常规锂离子电池正极材料是指晶体结构正常的表面为Li-O界面或者界面部分掺杂TM-O的锂离子电池正极材料。本申请直接对常规的锂离子电池正极材料进行预处理和后续的热处理，即可获得本申请的晶体结构的表面界面具有高电子电导的无机化合物层的锂离子电池正极材料。It should be noted that, in this application, conventional lithium-ion battery positive electrode materials refer to lithium-ion battery positive electrode materials whose surface is a Li-O interface with a normal crystal structure or the interface is partially doped with TM-O. The present application directly performs pretreatment and subsequent heat treatment on the conventional lithium-ion battery positive electrode material to obtain the lithium-ion battery positive electrode material with a crystal structure and an inorganic compound layer with high electronic conductivity on the surface interface of the present application.

本申请的一种实现方式中，经过步骤一和步骤二处理后的层状材料表面高电子电导的无机化合物与体相层状材料存在化学键合，结构上呈现同晶格外延生长特征，表面区域高电子电导的无机化合物厚度小于或等于5nm。In one implementation of the present application, the inorganic compound with high electronic conductivity on the surface of the layered material after step 1 and step 2 is chemically bonded to the bulk layered material, and the structure shows the same lattice epitaxial growth characteristics, and the surface area The thickness of the inorganic compound with high electronic conductivity is less than or equal to 5nm.

本申请的一种实现方式中，本申请制备方法采用的惰性气氛为N ₂和/或Ar；还原性气氛为N ₂加H ₂的气氛，或者Ar加H ₂的气氛。 In one implementation of the present application, the inert atmosphere used in the preparation method of the present application is _N2 and/or Ar; the reducing atmosphere is an atmosphere of _N2 plus _H2 , or an atmosphere of Ar plus _H2 .

需要说明的是，本申请中，层状正极材料表面高电子电导的无机化合物与体相层状材料的化学键合和同晶格外延生长的两个特征，是通过步骤二中的热处理过程实现的。可以理解，如果没有化学键合和同晶格外延生长的特征，层状正极材料的结构完整性和充放电过程中的锂离子嵌入/脱出动力学是无法得到保障的。同时，需要说明的是，本申请优化和调控了步骤二的热处理温度/时间及热处理的气氛条件，在实现化学键合和同晶格外延生长的同时，尽可能的减少表面无机化合物层与层状正极材料之间的互扩散，使表面无机化合物中的氧缺陷得以保持，从而获得高电子电导的界面无机化合物层。可以理解，如步骤二中热处理温度过高或热处理时间过长，或将材料置于含氧气的氧化性气氛中处理，表面无机化合物层中的氧缺陷消失，则不能获得高的电子电导。It should be noted that, in this application, the chemical bonding of the inorganic compound with high electronic conductivity on the surface of the layered positive electrode material and the bulk layered material and the two characteristics of homogeneous epitaxial growth are realized through the heat treatment process in step 2 . It is understandable that without the features of chemical bonding and iso-lattice epitaxial growth, the structural integrity of layered cathode materials and the Li-ion intercalation/extraction kinetics during charge and discharge cannot be guaranteed. At the same time, it should be noted that this application optimizes and regulates the heat treatment temperature/time and heat treatment atmosphere conditions in step 2, while achieving chemical bonding and homogeneous epitaxial growth, reducing the surface inorganic compound layer and layered structure as much as possible. The interdiffusion between positive electrode materials keeps the oxygen vacancies in the surface inorganic compound, thereby obtaining an interfacial inorganic compound layer with high electronic conductivity. It can be understood that if the heat treatment temperature is too high or the heat treatment time is too long in step 2, or the material is treated in an oxidative atmosphere containing oxygen, the oxygen vacancies in the surface inorganic compound layer will disappear, and high electronic conductivity cannot be obtained.

还需要说明的是，本申请中，表面区域高电子电导的无机化合物厚度需小于或等于5nm。可以理解，本申请中，厚度小于或等于5nm的导电无机化合物层，主要是为了降低锂离子嵌入/脱出的界面无机化合物层的扩散距离，降低扩散能垒，提高扩散动力学。可以理解，在该无机化合物层的厚度高于5nm的情况下，尽管界面处化合物层的电子电导较高，但锂离子在界面处的扩散受阻，也不利于容量和倍率性能的发挥。It should also be noted that in this application, the thickness of the inorganic compound with high electronic conductivity in the surface area must be less than or equal to 5 nm. It can be understood that in this application, the conductive inorganic compound layer with a thickness less than or equal to 5nm is mainly to reduce the diffusion distance of the intercalation/extraction interface inorganic compound layer of lithium ions, reduce the diffusion energy barrier, and improve the diffusion kinetics. It can be understood that when the thickness of the inorganic compound layer is higher than 5 nm, although the electronic conductivity of the compound layer at the interface is high, the diffusion of lithium ions at the interface is hindered, which is also not conducive to the performance of capacity and rate performance.

本申请的再一面公开了本申请的锂离子电池正极材料在制备动力电池、大规模储能电池，或者3C消费电子产品、无人机或电子烟的离子电池中的应用。Another aspect of the present application discloses the application of the lithium-ion battery cathode material of the present application in the preparation of power batteries, large-scale energy storage batteries, or ion batteries for 3C consumer electronics products, drones or electronic cigarettes.

可以理解，本申请的锂离子电池正极材料具有在高电压下的高容量、高倍率和循环稳定性好等优点，能够更好的用于动力电池和大规模储能电池，例如电动汽车或其他中大型电动设备或储能电站电源。同样的，本申请的锂离子电池正极材料也能够用于3C消费电子产品、无人机或电子烟的锂离子电池。It can be understood that the lithium-ion battery positive electrode material of the present application has the advantages of high capacity at high voltage, high rate and good cycle stability, and can be better used for power batteries and large-scale energy storage batteries, such as electric vehicles or other Power supply for medium and large electric equipment or energy storage power station. Similarly, the lithium-ion battery cathode material of the present application can also be used in lithium-ion batteries of 3C consumer electronics products, unmanned aerial vehicles or electronic cigarettes.

本申请的再一面公开了一种采用本申请的锂离子电池正极材料的锂离子电池。Another aspect of the present application discloses a lithium ion battery using the lithium ion battery cathode material of the present application.

可以理解，本申请的锂离子电池，由于采用本申请的锂离子电池正极材料，使得电池能够在更高的充放电电压下工作，并且具有更高的可逆充放电容量和倍率，且循环稳定性更好。It can be understood that the lithium ion battery of the present application, due to the use of the lithium ion battery cathode material of the present application, enables the battery to work at a higher charge and discharge voltage, and has a higher reversible charge and discharge capacity and rate, and cycle stability better.

本申请的有益效果在于：The beneficial effect of this application is:

本申请的锂离子电池正极材料，其无机化合物层能够阻隔过渡金属与电解液，抑制高电压下过渡金属离子对电解液的催化分解作用，降低循环过程中电极表面副反应，且通过降低电极极化增加Li ⁺嵌入动力学，从而使本申请的锂离子电池正极材料在高电压下也具有高容量、高倍率和循环稳定性好等优点。此外，本申请的锂离子电池正极材料制备方法简单，易于大规模工业化生产。 The anode material of the lithium ion battery of the present application, its inorganic compound layer can block the transition metal and the electrolyte, suppress the catalytic decomposition of the transition metal ion to the electrolyte under high voltage, reduce the side reaction of the electrode surface in the cycle process, and by reducing the ^Li increases the intercalation kinetics, so that the lithium-ion battery cathode material of the present application also has the advantages of high capacity, high rate and good cycle stability under high voltage. In addition, the preparation method of the positive electrode material for lithium ion batteries of the present application is simple and easy for large-scale industrial production.

附图说明Description of drawings

图1是本申请实施例中LiCoO ₂@O _d-Al ₂O _3-x材料的XRD精修结果； Fig. 1 is the XRD refinement result of the LiCoO ₂ @O _d -Al ₂ O _3-x material in the example of the present application;

图2是本申请实施例中LiCoO ₂@O _d-Al ₂O _3-x材料的TEM-mapping结果； Fig. 2 is the TEM-mapping result of the LiCoO ₂ @O _d -Al ₂ O _3-x material in the example of the present application;

图3是本申请实施例中LiCoO ₂@O _d-Al ₂O _3-x材料与商业化LiCoO ₂的电化学倍率性能结果；其中，(a)图为LiCoO ₂@O _d-Al ₂O _3-x材料的电化学倍率性能结果，(b)图为商业化LiCoO ₂的电化学倍率性能结果； Figure 3 is the electrochemical rate performance results of LiCoO ₂ @O _d -Al ₂ O _3-x materials and commercial LiCoO ₂ in the examples of this application; among them, (a) is LiCoO ₂ @O _d -Al ₂ O ₃ The electrochemical rate performance results of _-x materials, (b) shows the electrochemical rate performance results of commercial LiCoO ₂ ;

图4是本申请实施例中LiCoO ₂@O _d-Al ₂O _3-x材料与商业化LiCoO ₂的循环稳定性测试结果； Figure 4 is the cycle stability test results of LiCoO ₂ @O _d -Al ₂ O _3-x material and commercial LiCoO ₂ in the examples of the present application;

图5是本申请实施例中LiCoO ₂@Li-Al-Co-O-F材料的XRD精修结果； Fig. 5 is the XRD refinement result of LiCoO ₂ @Li-Al-Co-OF material in the example of the present application;

图6是本申请实施例中LiCoO ₂@Li-Al-Co-O-F材料在3-4.6V vs.Li/Li ⁺电位区间的0.2-8C的倍率性能； Figure 6 shows the rate performance of the LiCoO ₂ @Li-Al-Co-OF material in the embodiment of the present application at 0.2-8C in the 3-4.6V vs. Li/Li ⁺ potential range;

图7是本申请实施例中LiCoO ₂@Li-Al-Co-O-F材料在3-4.6V vs.Li/Li ⁺电位区间的1C循环性能。 Fig. 7 shows the 1C cycle performance of the LiCoO ₂ @Li-Al-Co-OF material in the example of the present application in the potential range of 3-4.6V vs. Li/Li ⁺ .

具体实施方式Detailed ways

本申请研究显示，无机的层状正极材料，包括LiCoO ₂、NMC和NCA材料，在高电压下，会面临诸多问题，包括电解液分解导致内阻增加、电极材料晶格坍塌和氧损失等，这些问题制约了层状正极材料电化学性能的进一步提升。通过包覆优化正极材料界面，抑制高电压下材料晶体结构衰退和延缓界面副反应，是目前比较通用的一种策略。 The research of this application shows that inorganic layered cathode materials, including LiCoO ₂ , NMC and NCA materials, will face many problems under high voltage, including electrolyte decomposition leading to increased internal resistance, electrode material lattice collapse and oxygen loss, etc. These problems restrict the further improvement of the electrochemical performance of layered cathode materials. Optimizing the interface of the positive electrode material by coating, suppressing the degradation of the crystal structure of the material under high voltage and delaying the side reaction at the interface is a relatively common strategy at present.

在以往研究中，人们针对包覆层物化性质的研究关注点在提升离子电导和不参与氧化还原反应，但从提升电子电导角度优化界面的方向研究较少。本申请研究显示，通过提升层状正极材料晶体结构表面界面的电子电导，能有效的降低界面极化，进而获得较低的电池内阻，有效助力提升电池功率。In previous studies, the focus of research on the physical and chemical properties of the coating layer was to improve ionic conductance and not participate in redox reactions, but there were few studies on optimizing the interface from the perspective of improving electronic conductance. The research of this application shows that by improving the electronic conductance of the surface interface of the crystal structure of the layered positive electrode material, the interface polarization can be effectively reduced, thereby obtaining a lower internal resistance of the battery, and effectively helping to increase the power of the battery.

此外，高电压下层状正极材料的过渡族金属层对电解液的催化作用，是导致热效应和内阻增加的关键。本申请研究发现，通过物理隔离电解液和电极材料的直接接触可有效抑制该催化作用，极大抑制副反应发生，使正极材料的界面优化得到保持，进而获得高的循环稳定性。In addition, the catalytic effect of the transition metal layer of the layered cathode material on the electrolyte at high voltage is the key to the thermal effect and the increase in internal resistance. The research of this application found that by physically isolating the direct contact between the electrolyte and the electrode material, the catalytic effect can be effectively suppressed, the occurrence of side reactions can be greatly suppressed, the interface optimization of the positive electrode material can be maintained, and high cycle stability can be obtained.

基于以上研究及认识，本申请从提高界面无机化合物层的电子电导，形成一层导电、导锂、不参与电化学反应的界面无机化合物层、且抑制高电压下过渡族金属层界面催化入手，提高界面稳定性的同时，提升了Li ⁺在界面处的嵌入动力学，因而获得高的容量和倍率性能。 Based on the above research and understanding, the present application starts from improving the electronic conductance of the interface inorganic compound layer, forming a layer of interface inorganic compound layer that is conductive, lithium-conducting, and does not participate in electrochemical reactions, and inhibits the interfacial catalysis of the transition metal layer under high voltage. While improving the interfacial stability, the intercalation kinetics of Li ⁺ at the interface is improved, resulting in high capacity and rate performance.

因此，本申请提供了一种锂离子电池正极材料，该锂离子电池正极材料的晶体结构的表面界面具有一层导电、导锂，且不参与电极与溶液的界面电化学副反应或化学副反应的无机化合物层。本申请的一种实现方式中，该无机化合物层是通过对晶体结构的表面界面进行元素替换/掺杂形成；例如，采用B、Al、Mg、Ca、Zn、Zr、Ti、In、Sn和Y中的至少一种替换表面界面的部分锂和/或过渡金属，和/或采用氟替换表面界面的部分或全部氧。Therefore, the present application provides a lithium-ion battery positive electrode material, the surface interface of the crystal structure of the lithium-ion battery positive electrode material has a layer of conduction and lithium conduction, and does not participate in the electrochemical side reaction or chemical side reaction of the interface between the electrode and the solution. layer of inorganic compounds. In one implementation of the present application, the inorganic compound layer is formed by replacing/doping elements on the surface interface of the crystal structure; for example, using B, Al, Mg, Ca, Zn, Zr, Ti, In, Sn and At least one of Y replaces part of the lithium and/or transition metal at the surface interface, and/or replaces part or all of the oxygen at the surface interface with fluorine.

本申请通过表面界面元素替换形成的无机化合物层，引入导电性降低极化电阻，同时通过物理隔绝层状材料过渡族金属层与电解液的直接接触，提高高电压稳定性；因此具有诸多优点，不仅导电、导锂、不参与电化学反应，而且抑制了副反应，在高电压下表现出高的容量、倍率和循环稳定性。This application replaces the inorganic compound layer formed by surface interface elements, introduces conductivity to reduce polarization resistance, and at the same time improves high voltage stability by physically isolating the direct contact between the transition metal layer of the layered material and the electrolyte; therefore, it has many advantages. It not only conducts electricity, guides lithium, does not participate in electrochemical reactions, but also suppresses side reactions, and exhibits high capacity, rate and cycle stability at high voltages.

本申请的一种实现方式中，主要是通过对常规的锂离子电池正极材料进行预处理和热处理，形成表面界面元素替换的无机化合物层。其中，预处理类似于现有技术的表面包覆修饰；所不同的是，按照本申请的条件进行预处理后进行后续的热处理，能够更有效的实现层状正极材料晶体结构表面界面的元素替换。因此，本申请的高电压锂离子电池复合层状电极材料，制备方法简单，容易实现工业化。In one implementation of the present application, the inorganic compound layer replaced by surface interface elements is mainly formed by performing pretreatment and heat treatment on conventional lithium-ion battery cathode materials. Among them, the pretreatment is similar to the surface coating modification of the prior art; the difference is that the subsequent heat treatment after the pretreatment according to the conditions of the present application can more effectively realize the element replacement of the crystal structure surface interface of the layered positive electrode material . Therefore, the composite layered electrode material for a high-voltage lithium ion battery of the present application has a simple preparation method and is easy to realize industrialization.

下面通过具体实施例对本申请作进一步详细说明。以下实施例仅对本申请进行进一步说明，不应理解为对本申请的限制。The present application will be described in further detail below through specific examples. The following examples only further illustrate the present application, and should not be construed as limiting the present application.

实施例一Embodiment one

本例首先采用碳酸锂和四氧化三钴为原材料制备钴酸锂，然后对钴酸锂进行预处理和热处理，获得本例的晶体结构的表面界面通过元素替换形成无机化合物层的钴酸锂。具体制备方法如下：In this example, lithium cobalt oxide and lithium cobalt oxide were firstly prepared as raw materials, and then lithium cobalt oxide was pretreated and heat-treated to obtain lithium cobalt oxide in which the surface interface of the crystal structure of this example was replaced by elements to form an inorganic compound layer. The specific preparation method is as follows:

钴酸锂材料烧结制备：将碳酸锂和四氧化三钴(D ₅₀在4-8微米之间)按照Li/Co比1.03混料均匀后，将混合均匀的混合粉末采用100目筛分机过筛，备用。将混合均匀并过筛后的混合样品在空气气氛下，1000℃烧结12h。将所获得的LCO材料碾碎，并通过100目筛分机过筛后，再次在空气气氛下烧结，900℃烧结6h。将所获得的粉末样品再次碾碎并通过100目筛粉机过筛，获得合格的钴酸锂(LiCoO ₂)粉末，备用。 Lithium cobaltate material sintering preparation: Lithium carbonate and cobalt tetroxide (D ₅₀ between 4-8 microns) are evenly mixed according to the Li/Co ratio of 1.03, and the evenly mixed mixed powder is sieved by a 100-mesh sieving machine, and set aside. The mixed samples that were mixed evenly and sieved were sintered at 1000°C for 12h in an air atmosphere. The obtained LCO material was crushed and sieved through a 100-mesh sieving machine, and then sintered again in an air atmosphere at 900° C. for 6 h. The obtained powder sample was crushed again and sieved through a 100-mesh sieve powder machine to obtain qualified lithium cobaltate (LiCoO ₂ ) powder for future use.

步骤一，预处理，按照聚乙烯醇:水＝1:20比例配制聚乙烯醇溶液30mL，在搅拌过程中，向溶液加入4g的LiCoO ₂，获得悬浊液A；将0.15g硫酸铝和0.05g的硫酸锂加入到10mL水中，搅拌溶解，获得溶液B；将溶液B在持续搅拌过程中逐滴加入到溶液A中，并在60℃水浴环境中保温3h。将所获得的悬浊溶液采用负压蒸馏方法，将水溶液蒸干，获得成功预处理的LiCoO ₂粉末。 Step 1, pretreatment, prepare 30 mL of polyvinyl alcohol solution according to the ratio of polyvinyl alcohol: water = 1:20, and add 4 g of LiCoO ₂ to the solution during stirring to obtain suspension A; mix 0.15 g of aluminum sulfate and 0.05 g of lithium sulfate was added to 10 mL of water, stirred and dissolved to obtain solution B; solution B was added dropwise to solution A during continuous stirring, and kept at 60°C for 3 hours in a water bath environment. The obtained suspension solution was evaporated to dryness by negative pressure distillation method to obtain successfully pretreated _LiCoO2 powder.

步骤二，后续热处理，将上述预处理的LiCoO ₂粉末，在空气气氛下，600℃热处理6h后，自然降温，将所获得的粉末100目过筛，获得无机化合物层为具有β-Al ₂O ₃结构的高迁移率单价阳离子氧化物的钴酸锂，即无机化合物层中具有带空位氧化铝，标记为LiCoO ₂@O _d-Al ₂O _3-x。其中，x＝0.01-0.50。 Step 2, subsequent heat treatment, heat-treat the above-mentioned pretreated LiCoO ₂ powder in an air atmosphere at 600°C for 6 hours, then lower the temperature naturally, and pass the obtained powder through a 100-mesh sieve to obtain an inorganic compound layer with β-Al ₂ O _3- structure lithium cobaltate of high-mobility monovalent cation oxides, that is, alumina with vacancies in the inorganic compound layer, marked as LiCoO ₂ @O _d -Al ₂ O _3-x . Wherein, x=0.01-0.50.

电化学测试：采用NMP作为溶剂，将LiCoO ₂@O _d-Al ₂O _3-x、炭黑和PVDF以质量比8:1:1的比例均匀混合，制备成正极极片，活性物质载量约为4.5mg cm ^-2。使用2032纽扣电池制备以锂片作为负极的半电池，使用Celgard 2035隔膜和高电压电解液(质量比LiPF6:EMC:FEC＝15:55:30)，将该半电池在3-4.6V(vs.Li/Li ⁺)之间循环，全电池的N/P比约为1.15，商用石墨碳微球负极由深圳BTR新能源材料公司提供。 Electrochemical test: Using NMP as a solvent, LiCoO ₂ @O _d -Al ₂ O _3-x , carbon black and PVDF were uniformly mixed in a mass ratio of 8:1:1 to prepare a positive electrode sheet. The active material loading About 4.5mg cm ^-2 . Use a 2032 button cell to prepare a half-cell with a lithium sheet as the negative electrode, use a Celgard 2035 diaphragm and a high-voltage electrolyte (mass ratio LiPF6:EMC:FEC=15:55:30), and set the half-cell at 3-4.6V (vs .Li/Li ⁺ ), the N/P ratio of the full battery is about 1.15, and the commercial graphite carbon microsphere negative electrode is provided by Shenzhen BTR New Energy Materials Company.

本例针对制备的LiCoO ₂@O _d-Al ₂O _3-x材料的物性及电化学性能进行表征XRD精修，结果如图1所示。图1的结果表明，所得LiCoO ₂@O _d-Al ₂O _3-x与标准的常规钴酸锂的层状结构完全一致。TEM EDS-mapping结果如图2所示，图2的结果显示，Al元素在LiCoO ₂@O _d-Al ₂O _3-x表面界面富集。电池倍率性能的测试结果如图3所示，图3的结果表明，LiCoO ₂@O _d-Al ₂O _3-x材料在0.2C电流密度下，放电容量为231mAh g ^-1，中值电压为4.035V，正极活性材料的能量密度932Wh/kg；LiCoO ₂@O _d-Al ₂O _3-x材料在8C电流密度下，放电容量为179mAh g ^-1，中值电压为3.948V，正极活性材料的能量密度超过708Wh/kg。同时，电池1C循环200圈后的测试结果如图4所示，图4的结果表明，循环100圈后，容量保持率为81％。作为对比，商业化LiCoO ₂(翔鹰公司，XY006)容量基本无差别，但循环100圈后容量保持率仅7％。本例的LiCoO ₂@O _d-Al ₂O _3-x材料在高电压下的倍率和循环稳定性均大幅提升。 In this example, the physical properties and electrochemical properties of the prepared LiCoO ₂ @O _d -Al ₂ O _3-x material were characterized by XRD refinement, and the results are shown in Figure 1. The results in Fig. 1 show that the obtained LiCoO ₂ @O _d -Al ₂ O _3-x is completely consistent with the layered structure of standard conventional lithium cobalt oxide. The TEM EDS-mapping results are shown in Figure 2. The results in Figure 2 show that Al elements are enriched at the surface interface of LiCoO ₂ @O _d -Al ₂ O _3-x . The test results of the rate performance of the battery are shown in Figure 3. The results in Figure 3 show that the LiCoO ₂ @O _d -Al ₂ O _3-x material has a discharge capacity of 231mAh g ^-1 at a current density of 0.2C, and a median voltage of 4.035V, the energy density of the positive electrode active material is 932Wh/kg; LiCoO ₂ @O _d -Al ₂ O _3-x material has a discharge capacity of 179mAh g ^-1 at a current density of 8C, and the median voltage is 3.948V, the positive electrode active material The energy density exceeds 708Wh/kg. At the same time, the test results of the battery 1C after 200 cycles are shown in Figure 4. The results in Figure 4 show that after 100 cycles, the capacity retention rate is 81%. As a comparison, commercialized LiCoO ₂ (Xiangying Company, XY006) has basically no difference in capacity, but the capacity retention rate is only 7% after 100 cycles. The rate and cycle stability of the LiCoO ₂ @O _d -Al ₂ O _3-x material in this example are greatly improved under high voltage.

实施例二Embodiment two

本例采用实施例一相同的钴酸锂粉末进行预处理和热处理，获得本例的晶体结构的表面界面通过元素替换形成无机化合物层的钴酸锂。所不同的是，本例的预处理和热处理的具体材料和条件有所不同。具体如下：In this example, the same lithium cobaltate powder as in Example 1 was used for pretreatment and heat treatment, and the surface interface of the crystal structure of this example was replaced with lithium cobaltate to form an inorganic compound layer. The difference is that the specific materials and conditions of the pretreatment and heat treatment in this example are different. details as follows:

步骤一，预处理，在80mL去离子水中，加入4g实施例一制备的LiCoO ₂，持续搅拌均匀，获得悬浊液A；将0.15g硫酸铝加入到40mL去离子水中，搅拌溶解，获得溶液B；将0.10g的氟化铵加入到40mL去离子水中，搅拌溶解，获得溶液C。在25℃条件下，首先在搅拌过程中，将溶液B逐滴加入到悬浊液A中，形成溶液D；将溶液D继续搅拌10min后，将溶液C逐滴加入到溶液D中，形成悬浊液E。将悬浊液E继续搅拌1h后，将悬浊液进行抽滤，采用去离子水和酒精清洗，真空烘箱80℃烘干，并经过100目筛网过筛，备用； Step 1, pretreatment, add 4g of LiCoO ₂ prepared in Example 1 to 80mL of deionized water, and keep stirring evenly to obtain suspension A; add 0.15g of aluminum sulfate to 40mL of deionized water, stir and dissolve to obtain solution B ; Add 0.10 g of ammonium fluoride to 40 mL of deionized water, stir and dissolve to obtain solution C. Under the condition of 25°C, firstly, during the stirring process, solution B was added dropwise to suspension A to form solution D; after solution D was stirred for 10 minutes, solution C was added dropwise to solution D to form suspension Turbid liquid E. Continue to stir the suspension E for 1 hour, filter the suspension with deionized water and alcohol, dry in a vacuum oven at 80°C, and pass through a 100-mesh sieve for later use;

步骤二，热处理烧结，将上述预处理的LiCoO ₂粉末，在空气气氛下，500℃热处理6h后，自然降温，将所获得的粉末100目过筛，获得无机化合物层为带有氧缺陷的富锂氟氧化物的钴酸锂，标记为LiCoO ₂@Li-Al-Co-O-F。 Step 2, heat treatment and sintering, the above-mentioned pretreated LiCoO ₂ powder is heat-treated at 500°C for 6 hours in an air atmosphere, and then the temperature is naturally lowered, and the obtained powder is sieved with 100 meshes to obtain an inorganic compound layer with oxygen defects. Lithium cobaltate of lithium oxyfluoride, labeled as _LiCoO2 @Li-Al-Co-OF.

电化学测试：采用NMP作为溶剂，将LiCoO ₂@Li-Al-Co-O-F、炭黑和PVDF以质量比8:1:1的比例均匀混合，制备成正极极片，活性物质载量约为4.5mg cm ^-2。使用2032纽扣电池制备以锂片作为负极的半电池，使用Celgard 2035隔膜和高电压电解液(质量比LiPF6:EMC:FEC＝15:55:30)，将该半电池在3-4.6V(vs.Li/Li ⁺)之间循环，全电池的N/P比约为1.15，商用石墨碳微球负极由深圳BTR新能源材料公司提供。 Electrochemical test: Using NMP as a solvent, LiCoO ₂ @Li-Al-Co-OF, carbon black and PVDF were uniformly mixed at a mass ratio of 8:1:1 to prepare a positive electrode sheet with an active material loading of about 4.5 mg cm ^-2 . Use a 2032 button cell to prepare a half-cell with a lithium sheet as the negative electrode, use a Celgard 2035 diaphragm and a high-voltage electrolyte (mass ratio LiPF6:EMC:FEC=15:55:30), and set the half-cell at 3-4.6V (vs .Li/Li ⁺ ), the N/P ratio of the full battery is about 1.15, and the commercial graphite carbon microsphere negative electrode is provided by Shenzhen BTR New Energy Materials Company.

本例针对制备的LiCoO ₂@Li-Al-Co-O-F材料的物性及电化学性能进行表征XRD精修，结果如图5所示。图5的结果表明，所得LiCoO ₂@Li-Al-Co-O-F与标准的常规钴酸锂层状结构的钴酸锂完全一致。电池倍率性能的测试结果如图6所示，图6的结果表明，LiCoO ₂@Li-Al-Co-O-F材料在0.2C电流密度下，放电容量为228mAh g ^-1，中值电压为4.042V，正极活性材料的能量密度924Wh/kg；LiCoO ₂@Li-Al-Co-O-F材料在8C电流密度下，放电容量为193mAh g ^-1，中值电压为3.956V，正极活性材料的能量密度超过764Wh/kg。同时，电池1C循环200圈后的测试结果如图7所示，图7的结果表明，循环200圈后，容量保持率为超过85％。因此，本例制备的LiCoO ₂@Li-Al-Co-O-F材料在高电压下表现出优异的倍率和循环稳定性。 In this example, the physical properties and electrochemical properties of the prepared LiCoO ₂ @Li-Al-Co-OF material were characterized by XRD refinement, and the results are shown in Figure 5. The results in Fig. 5 show that the obtained LiCoO ₂ @Li-Al-Co-OF is completely consistent with the standard conventional lithium cobalt oxide layered lithium cobalt oxide. The test results of the battery rate performance are shown in Figure 6. The results in Figure 6 show that the LiCoO ₂ @Li-Al-Co-OF material has a discharge capacity of 228mAh g ^-1 and a median voltage of 4.042V at a current density of 0.2C. , the energy density of the positive electrode active material is 924Wh/kg; LiCoO ₂ @Li-Al-Co-OF material has a discharge capacity of 193mAh g ^-1 and a median voltage of 3.956V at a current density of 8C, and the energy density of the positive electrode active material exceeds 764Wh/kg. At the same time, the test results of the battery 1C after 200 cycles are shown in Figure 7. The results in Figure 7 show that after 200 cycles, the capacity retention rate exceeds 85%. Therefore, the LiCoO ₂ @Li-Al-Co-OF material prepared in this example exhibits excellent rate and cycle stability at high voltage.

实施例三Embodiment three

步骤一，合成纳米辅料及预处理，按照摩尔比0.05:1称量CaO和 ZrOCl ₂·8H ₂O，并用5:1的硝酸稀溶液溶解，形成溶液A；将溶液A缓慢的滴入到溶有聚乙二醇的氨水溶液中，在磁力搅拌条件下反应2h，陈化、抽滤、采用去离子水和无水乙醇清洗，80℃真空干燥24h，获得纳米粉末，备用；将上述粉末与钴酸锂粉末以质量比0.025:0.975的比例混合均匀，采用球磨混料研磨30min至完全均匀，将获得的混合粉末采用100目筛网过筛，备用； Step 1, synthesis of nano-excipients and pretreatment, weigh CaO and ZrOCl ₂ 8H ₂ O according to the molar ratio of 0.05:1, and dissolve them with a 5:1 dilute nitric acid solution to form solution A; slowly drop solution A into the solution In an ammonia solution containing polyethylene glycol, react under magnetic stirring conditions for 2 hours, age, filter with suction, wash with deionized water and absolute ethanol, and dry in vacuum at 80°C for 24 hours to obtain a nano-powder for use; mix the above powder with Lithium cobaltate powder is mixed evenly at a mass ratio of 0.025:0.975, and ground for 30 minutes until completely uniform by ball milling, and the obtained mixed powder is sieved through a 100-mesh sieve, and set aside;

步骤二：热处理烧结，将上述预处理的混合粉末，在空气气氛下，500℃热处理6h后，自然降温，将所获得的粉末100目过筛，获得表面被ZrO ₂·0.05CaO包覆的钴酸锂粉末，标记为LiCoO ₂@ZrO ₂·0.05CaO。 Step 2: heat treatment and sintering, the above pretreated mixed powder is heat-treated at 500°C for 6 hours in an air atmosphere, and then the temperature is naturally lowered, and the obtained powder is sieved with 100 mesh to obtain cobalt coated with ZrO ₂ ·0.05CaO on the surface Lithium oxide powder, marked as LiCoO ₂ @ZrO ₂ ·0.05CaO.

电化学测试：采用NMP作为溶剂，将LiCoO ₂@ZrO ₂·0.05CaO、炭黑和PVDF以质量比8:1:1的比例均匀混合，制备成正极极片，活性物质载量约为4.5mg cm ^-2。使用2032纽扣电池制备以锂片作为负极的半电池，使用Celgard 2035隔膜和高电压电解液(质量比LiPF ₆:EMC:FEC＝15:55:30)，将该半电池在3-4.6V(vs.Li/Li ⁺)之间循环，全电池的N/P比约为1.15，商用石墨碳微球负极由深圳BTR新能源材料公司提供。 Electrochemical test: Using NMP as a solvent, LiCoO ₂ @ZrO ₂ ·0.05CaO, carbon black and PVDF were uniformly mixed at a mass ratio of 8:1:1 to prepare a positive electrode sheet with an active material loading of about 4.5mg cm ^-2 . Use 2032 button cells to prepare half batteries with lithium sheet as negative electrode, use Celgard 2035 diaphragm and high voltage electrolyte (mass ratio LiPF ₆ : EMC: FEC=15:55:30), this half battery is in 3-4.6V ( vs. Li/Li ⁺ ), the N/P ratio of the full battery is about 1.15, and the commercial graphite carbon microsphere anode is provided by Shenzhen BTR New Energy Materials Company.

本例针对制备的LiCoO ₂@ZrO ₂·0.05CaO材料的XRD精修结果表明，所得LiCoO ₂@ZrO ₂·0.05CaO与标准的常规钴酸锂层状结构的钴酸锂完全一致。电池倍率性能的测试结果表明，LiCoO ₂@ZrO ₂·0.05CaO材料在0.2C电流密度下，放电容量为236mAh g ^-1，中值电压为4.042V，正极活性材料的能量密度954Wh/kg；LiCoO ₂@ZrO ₂·0.05CaO材料在8C电流密度下，放电容量为203mAh g ^-1，中值电压为3.965V，正极活性材料的能量密度超过805Wh/kg。同时，电池1C循环200圈后的测试结果表明，循环200圈后，容量保持率为超过86％。因此，本例制备的LiCoO ₂@ZrO ₂·0.05CaO材料在高电压下表现出优异的倍率和循环稳定性。 The refined XRD results of the prepared LiCoO ₂ @ZrO ₂ ·0.05CaO material in this example show that the obtained LiCoO ₂ @ZrO ₂ ·0.05CaO is completely consistent with the standard conventional lithium cobalt oxide layered lithium cobalt oxide. The test results of battery rate performance show that LiCoO ₂ @ZrO ₂ ·0.05CaO material has a discharge capacity of 236mAh g ^-1 at a current density of 0.2C, a median voltage of 4.042V, and an energy density of 954Wh/kg as a positive electrode active material; LiCoO ₂ @ZrO ₂ ·0.05CaO material has a discharge capacity of 203mAh g ^-1 and a median voltage of 3.965V at a current density of 8C, and the energy density of the positive active material exceeds 805Wh/kg. At the same time, the test results of the battery 1C after 200 cycles show that the capacity retention rate exceeds 86% after 200 cycles. Therefore, the LiCoO ₂ @ZrO ₂ ·0.05CaO material prepared in this example exhibits excellent rate and cycle stability at high voltage.

同时，本实施例还采用同样的方法制备了LiCoO ₂@ZrO ₂·0.025Y ₂O ₃，通过电化学测试发现其在在0.2C电流密度下，放电容量为232mAh g ^-1，中值电压为4.036V，正极活性材料的能量密度936Wh/kg；在8C电流密度下，放电容量为196mAh g ^-1，中值电压为3.969V，正极活性材料的能量密度超过778Wh/kg。因此，本实施例制备的LiCoO ₂@ZrO ₂·0.05CaO材料在高电压下同样表现出优异的倍率和循环稳定性。 At the same time, LiCoO ₂ @ZrO ₂ ·0.025Y ₂ O ₃ was also prepared by the same method in this example. It was found through electrochemical tests that the discharge capacity was 232mAh g ^-1 and the median voltage was 4.036V, the energy density of the positive electrode active material is 936Wh/kg; at a current density of 8C, the discharge capacity is 196mAh g ^-1 , the median voltage is 3.969V, and the energy density of the positive electrode active material exceeds 778Wh/kg. Therefore, the LiCoO ₂ @ZrO ₂ ·0.05CaO material prepared in this example also exhibits excellent rate and cycle stability under high voltage.

实施例四Embodiment four

本例采用实施例三相同的方法对层状正极材料的粉末进行预处理和热处理，获得本例的晶体结构的表面界面通过元素替换形成无机化合物层的层状正极材料。所不同的是，本例的预处理和热处理的具体材料为LiNi _0.8Co _0.1Mn _0.1O ₂(NCM811)和LiNi _0.5Co _0.3Mn _0.2O ₂(NCM532)。经过步骤一到三处理后的材料分别命名为NCM811@ZrO ₂·0.05CaO和NCM532@ZrO ₂·0.05CaO。 In this example, the powder of the layered positive electrode material is pretreated and heat-treated by the same method as in Example 3 to obtain the layered positive electrode material in which the surface interface of the crystal structure of this example forms an inorganic compound layer through element replacement. The difference is that the specific materials for the pretreatment and heat treatment in this example are LiNi _0.8 Co _0.1 Mn _0.1 O ₂ (NCM811) and LiNi _0.5 Co _0.3 Mn _0.2 O ₂ (NCM532). The materials after steps 1 to 3 were named NCM811@ZrO ₂ ·0.05CaO and NCM532@ZrO ₂ ·0.05CaO respectively.

采用与实施例三相同的方法对所得的NCM811@ZrO ₂·0.05CaO进行电化学测试，发现其在0.2C电流密度和3-4.3V区间下，放电容量为216mAh g ^-1；在8C电流密度下，放电容量为126mAh g ^-1。相比之下，采用同样方法制备的NCM811@ZrO ₂，在0.2C和8C电流密度下的放电容量分别为188mAh g ^-1和92mAh g ^-1。 The obtained NCM811@ZrO ₂ ·0.05CaO was electrochemically tested by the same method as in Example 3, and it was found that the discharge capacity was 216mAh g ^-1 at a current density of 0.2C and in the range of 3-4.3V; at a current density of 8C , the discharge capacity was 126mAh g ^-1 . In contrast, NCM811@ZrO ₂ prepared by the same method has a discharge capacity of 188mAh g ^-1 and 92mAh g ^-1 at 0.2C and 8C, respectively.

采用与实施例三相同的方法对所得的NCM532@ZrO ₂·0.05CaO进行电化学测试，发现其在0.2C电流密度和3-4.3V区间下，放电容量为236mAh g ^-1；在8C电流密度下，放电容量为116mAh g ^-1。相比之下，采用同样方法制备的NCM532@ZrO ₂，在0.2C和8C电流密度下的放电容量分别为157mAh g ^-1和63mAh g ^-1。 The obtained NCM532@ZrO ₂ ·0.05CaO was electrochemically tested by the same method as in Example 3, and it was found that the discharge capacity was 236mAh g ^-1 at a current density of 0.2C and in the range of 3-4.3V; at a current density of 8C , the discharge capacity was 116mAh g ^-1 . In contrast, NCM532@ZrO ₂ prepared by the same method has a discharge capacity of 157mAh g ^-1 and 63mAh g ^-1 at 0.2C and 8C, respectively.

可以理解，本实施例中，通过元素掺杂/替换获得的NCM811@ZrO ₂·0.05CaO和NCM532@ZrO ₂·0.05CaO均比NCM811@ZrO ₂和NCM532@ZrO ₂具有更高的容量和倍率性能。 It can be understood that in this example, NCM811@ZrO ₂ ·0.05CaO and NCM532@ZrO ₂ ·0.05CaO obtained by element doping/replacement have higher capacity and rate performance than NCM811@ZrO ₂ and NCM532@ZrO ₂ .

实施例五Embodiment five

本例采用实施例三相同的方法对钴酸锂粉末进行预处理和热处理，获得本例的晶体结构的表面界面通过元素替换形成无机化合物层的钴酸锂。所不同的是，本实施例中，将步骤一中加入的CaO和ZrOCl ₂·8H ₂O进行替换，获得钴酸锂表面区域不同成分的无机化合物层。 In this example, the lithium cobaltate powder is pretreated and heat-treated by the same method as in Example 3, and the surface interface of the crystal structure of this example is replaced by elements to form the lithium cobaltate layer of the inorganic compound. The difference is that in this embodiment, the CaO and ZrOCl ₂ ·8H ₂ O added in step 1 are replaced to obtain inorganic compound layers with different compositions in the surface region of lithium cobaltate.

表1 不同化合物层的钴酸锂及其电化学性能测试结果Table 1 LiCoO3 in different compound layers and its electrochemical performance test results

编号serial number	0.2C容量0.2C capacity	8C容量8C capacity
LiCoO ₂@ZrO ₂ LiCoO ₂ @ZrO ₂	198mAh g ^-1 198mAh g ^-1	114mAh g ^-1 114mAh g ^-1
LiCoO ₂@ZrO ₂·0.05CaO LiCoO ₂ @ZrO ₂ ·0.05CaO	238mAh g ^-1 238mAh g ^-1	192mAh g ^-1 192mAh g ^-1
LiCoO ₂@ZrO ₂·0.05MgO LiCoO ₂ @ZrO ₂ ·0.05MgO	235mAh g ^-1 235mAh g ^-1	189mAh g ^-1 189mAh g ^-1

LiCoO ₂@ZrO ₂·0.025B ₂O ₃ LiCoO ₂ @ZrO ₂ ·0.025B ₂ O ₃	234mAh g ^-1 234mAh g ^-1	187mAh g ^-1 187mAh g ^-1
LiCoO ₂@ZrO ₂·0.025Y ₂O ₃ LiCoO ₂ @ZrO ₂ ·0.025Y ₂ O ₃	234mAh g ^-1 234mAh g ^-1	190mAh g ^-1 190mAh g ^-1
LiCoO ₂@TiO LiCoO ₂ @TiO	204mAh g ^-1 204mAh g ^-1	108mAh g ^-1 108mAh g ^-1
LiCoO ₂@Nb _0.05Ti _0.95O LiCoO ₂ @Nb _0.05 Ti _0.95 O	238mAh g ^-1 238mAh g ^-1	198mAh g ^-1 198mAh g ^-1
LiCoO ₂@In _0.05Ti _0.95O LiCoO ₂ @In _0.05 Ti _0.95 O	235mAh g ^-1 235mAh g ^-1	192mAh g ^-1 192mAh g ^-1
LiCoO ₂@Al ₂O ₃ LiCoO ₂ @Al ₂ O ₃	210mAh g ^-1 210mAh g ^-1	123mAh g ^-1 123mAh g ^-1
LiCoO ₂@Al ₂O ₃·0.05ZnO LiCoO ₂ @Al ₂ O ₃ ·0.05ZnO	238mAh g ^-1 238mAh g ^-1	186mAh g ^-1 186mAh g ^-1
LiCoO ₂@ZnO LiCoO ₂ @ZnO	198mAh g ^-1 198mAh g ^-1	124mAh g ^-1 124mAh g ^-1
LiCoO ₂@ZnO·0.025Al ₂O ₃ LiCoO ₂ @ZnO·0.025Al ₂ O ₃	238mAh g ^-1 238mAh g ^-1	192mAh g ^-1 192mAh g ^-1
LiCoO ₂@ZnO·0.025B ₂O ₃ LiCoO ₂ @ZnO 0.025B ₂ O ₃	234mAh g ^-1 234mAh g ^-1	198mAh g ^-1 198mAh g ^-1
LiCoO ₂@ZnO·0.025In ₂O ₃ LiCoO ₂ @ZnO·0.025In ₂ O ₃	235mAh g ^-1 235mAh g ^-1	194mAh g ^-1 194mAh g ^-1
LiCoO ₂@SnO ₂ LiCoO ₂ @SnO ₂	201mAh g ^-1 201mAh g ^-1	131mAh g ^-1 131mAh g ^-1
LiCoO ₂@SnO ₂·0.05ZnO LiCoO ₂ @SnO ₂ ·0.05ZnO	238mAh g ^-1 238mAh g ^-1	192mAh g ^-1 192mAh g ^-1
LiCoO ₂@SnO ₂·0.025Al ₂O ₃ LiCoO ₂ @SnO ₂ ·0.025Al ₂ O ₃	229mAh g ^-1 229mAh g ^-1	189mAh g ^-1 189mAh g ^-1
LiCoO ₂@In ₂O ₃ LiCoO ₂ @In ₂ O ₃	196mAh g ^-1 196mAh g ^-1	113mAh g ^-1 113mAh g ^-1
LiCoO ₂@In ₂O ₃·0.05ZnO LiCoO ₂ @In ₂ O ₃ ·0.05ZnO	235mAh g ^-1 235mAh g ^-1	189mAh g ^-1 189mAh g ^-1
LiCoO ₂@In ₂O ₃·0.05SnO ₂ LiCoO ₂ @In ₂ O ₃ ·0.05SnO ₂	232mAh g ^-1 232mAh g ^-1	193mAh g ^-1 193mAh g ^-1

表1中“@”符号后面的氧化物即无机化合物层。表1的结果显示，相比纯的氧化铝、氧化锌、氧化钛、氧化锡、氧化铟作为界面无机化合物层的钴酸锂正极材料，对相应氧化物进行元素掺杂后，由于氧空位存在导致表面无机化合物层的电子电导增加，正极材料的容量和倍率性能均显著提高。The oxides behind the "@" symbol in Table 1 are inorganic compound layers. The results in Table 1 show that compared with pure aluminum oxide, zinc oxide, titanium oxide, tin oxide, and indium oxide as the lithium cobaltate cathode material of the interface inorganic compound layer, after element doping of the corresponding oxide, due to the existence of oxygen vacancies As a result, the electronic conductance of the surface inorganic compound layer increases, and the capacity and rate performance of the cathode material are significantly improved.

以上内容是结合具体的实施方式对本申请所作的进一步详细说明，不能认定本申请的具体实施只局限于这些说明。对于本申请所属技术领域的普通技术人员来说，在不脱离本申请构思的前提下，还可以做出若干简单推演或替换。The above content is a further detailed description of the present application in conjunction with specific implementation modes, and it cannot be considered that the specific implementation of the present application is limited to these descriptions. For those of ordinary skill in the technical field to which the present application belongs, some simple deduction or replacement can also be made without departing from the concept of the present application.

Claims

一种锂离子电池正极材料，其特征在于：所述锂离子电池正极材料的晶体结构的表面界面具有一层导电、导锂，且不参与电极与溶液的界面电化学副反应或化学副反应的无机化合物层。A lithium-ion battery positive electrode material, characterized in that: the surface interface of the crystal structure of the lithium-ion battery positive electrode material has a layer of conduction and lithium conduction, and does not participate in the electrochemical side reaction or chemical side reaction of the interface between the electrode and the solution Inorganic compound layer.
根据权利要求1所述的锂离子电池正极材料，其特征在于：所述无机化合物层与体相层状材料存在化学键合；The lithium-ion battery positive electrode material according to claim 1, characterized in that: the inorganic compound layer is chemically bonded to the bulk layered material;

优选的，所述无机化合物层由体相层状材料相同晶格外延生长而成；Preferably, the inorganic compound layer is epitaxially grown from the same lattice of the bulk layered material;

优选的，所述无机化合物层厚度小于或等于5nm。Preferably, the thickness of the inorganic compound layer is less than or equal to 5 nm.
根据权利要求1或2所述的锂离子电池正极材料，其特征在于：所述无机化合物晶体结构中含有0.1-5.0％的氧缺陷，具体包括以下氧化物中的至少一种；The lithium-ion battery positive electrode material according to claim 1 or 2, characterized in that: the crystal structure of the inorganic compound contains 0.1-5.0% of oxygen defects, specifically including at least one of the following oxides;

(1)部分F替代O的含锂氧氟化物；(1) Lithium oxyfluoride containing part of F replacing O;

(2)Zn和/或Mg掺杂的氧化铝；(2) Zn and/or Mg doped alumina;

(3)Nb和/或In掺杂的氧化钛；(3) Nb and/or In-doped titanium oxide;

(4)Ca、Mg、B、Y中的至少一种掺杂的氧化锆；(4) Zirconia doped with at least one of Ca, Mg, B, and Y;

(5)Al、B和In中的至少一种掺杂的ZnO；(5) ZnO doped with at least one of Al, B and In;

(6)Zn和/或Al掺杂的SnO ₂； (6) Zn and/or Al doped SnO ₂ ;

(7)Zn和/或Sn掺杂的In ₂O ₃。 (7) Zn and/or Sn doped In ₂ O ₃ .
根据权利要求3所述的锂离子电池正极材料，其特征在于：所述部分F替代O的含锂氧氟化物的元素成分还包括Al和/或Co；The lithium-ion battery positive electrode material according to claim 3, characterized in that: the elemental composition of the lithium-containing oxyfluoride in which part of F is substituted for O also includes Al and/or Co;

优选的，Zn掺杂的氧化铝为Al ₂O ₃·xZnO，其中，0.01<x<0.10； Preferably, the Zn-doped alumina is Al ₂ O ₃ ·xZnO, where 0.01<x<0.10;

优选的，Nb掺杂的氧化钛为Nb _xTi _1-xO，In掺杂的氧化钛为In _yTi _1-yO，其中，0.01<x<0.10，0.01<y<0.10； Preferably, the Nb-doped titanium oxide is Nb _x Ti _1-x O, and the In-doped titanium oxide is In _y Ti _1-y O, wherein, 0.01<x<0.10, 0.01<y<0.10;

优选的，Ca掺杂的氧化锆为ZrO ₂·xCaO，Mg掺杂的氧化锆为ZrO ₂·yMgO，B掺杂的氧化锆为ZrO ₂·zB ₂O ₃，Y掺杂的氧化锆为ZrO ₂·rY ₂O ₃，其中，0.01<x<0.10，0.01<y<0.10，0.005<z<0.05，0.005<r<0.05； Preferably, the Ca-doped zirconia is ZrO ₂ ·xCaO, the Mg-doped zirconia is ZrO ₂ ·yMgO, the B-doped zirconia is ZrO ₂ ·zB ₂ O ₃ , and the Y-doped zirconia is ZrO ₂ rY ₂ O ₃ , wherein, 0.01<x<0.10, 0.01<y<0.10, 0.005<z<0.05, 0.005<r<0.05;

优选的，Al掺杂的ZnO为ZnO·xAl ₂O ₃，B掺杂的ZnO为ZnO·yB ₂O ₃，In掺杂的ZnO为ZnO·yIn ₂O ₃，其中0.005<x<0.05，0.005<y<0.05，0.005<z<0.05； Preferably, Al-doped ZnO is ZnO·xAl ₂ O ₃ , B-doped ZnO is ZnO·yB ₂ O ₃ , and In-doped ZnO is ZnO·yIn ₂ O ₃ , wherein 0.005<x<0.05, 0.005 <y<0.05, 0.005<z<0.05;

优选的，Zn掺杂的SnO ₂为SnO ₂·xZnO，Al掺杂的SnO ₂为SnO ₂·yAl ₂O ₃，其中0.01<x<0.10，0.005<y<0.05； Preferably, the Zn-doped SnO ₂ is SnO ₂ ·xZnO, and the Al-doped SnO ₂ is SnO ₂ ·yAl ₂ O ₃ , wherein 0.01<x<0.10, 0.005<y<0.05;

优选的，Zn掺杂的In ₂O ₃为In ₂O ₃·xZnO，Sn掺杂的In ₂O ₃为In ₂O ₃·ySnO ₂，其中，0.01<x<0.10，0.01<y<0.10。 Preferably, Zn-doped In ₂ O ₃ is In ₂ O ₃ ·xZnO, and Sn-doped In ₂ O ₃ is In ₂ O ₃ ·ySnO ₂ , wherein 0.01<x<0.10, 0.01<y<0.10.
根据权利要求1所述的锂离子电池正极材料，其特征在于：所述锂离子电池正极材料为通式Li _1+xTMO _2+y的层状正极材料，其中，0≤x≤1，0≤y≤1，TM为过渡金属，TM选自Co、Ni、Mn和Al中的至少一种。 The lithium-ion battery positive electrode material according to claim 1, characterized in that: the lithium-ion battery positive electrode material is a layered positive electrode material of the general formula Li _1+x TMO _2+y , wherein 0≤x≤1,0 ≤y≤1, TM is a transition metal, and TM is selected from at least one of Co, Ni, Mn and Al.
根据权利要求5所述的锂离子电池正极材料，其特征在于：所述锂离子电池正极材料为钴酸锂、高镍二元材料、高镍多元材料、富锂锰正极材料中的至少一种；The lithium-ion battery cathode material according to claim 5, wherein the lithium-ion battery cathode material is at least one of lithium cobalt oxide, high-nickel binary material, high-nickel multi-element material, and lithium-rich manganese cathode material ;

所述高镍是指镍含量大于或等于50％；The high nickel refers to that the nickel content is greater than or equal to 50%;

优选的，所述锂离子电池正极材料为LiNi _0.8Co _0.1Mn _0.1O ₂、LiNi _0.5Co _0.3Mn _0.2O ₂和LiCoO ₂中的至少一种。 Preferably, the positive electrode material of the lithium ion battery is at least one of LiNi _0.8 Co _0.1 Mn _0.1 O ₂ , LiNi _0.5 Co _0.3 Mn _0.2 O ₂ and LiCoO ₂ .
根据权利要求1-6任一项所述的锂离子电池正极材料的制备方法，其特征在于：包括对常规锂离子电池正极材料进行以下处理，获得晶体结构的表面界面具有无机化合物层的锂离子电池正极材料；According to the preparation method of lithium ion battery cathode material according to any one of claims 1-6, it is characterized in that: comprising carrying out following treatment to conventional lithium ion battery cathode material, the surface interface of obtaining crystal structure has the lithium ion of inorganic compound layer battery cathode material;

步骤一，采用以下方法中的至少一种对常规锂离子电池正极材料进行预处理，Step 1, using at least one of the following methods to pretreat conventional lithium-ion battery cathode materials,

(a)固相球磨法，包括将常规锂离子电池正极材料与含Zn、Al、Ca、Mg、Zr、Ti、Y、In、Sn、B和F的至少一种的纳米固体粉料一起进行球磨混料，获得预处理的电池层状正极材料；(a) solid-phase ball milling method, comprising conventional lithium-ion battery cathode material and nano solid powder containing at least one of Zn, Al, Ca, Mg, Zr, Ti, Y, In, Sn, B and F Ball milling and mixing to obtain pretreated battery layered positive electrode materials;

(b)液相溶液预处理，包括将常规锂离子电池正极材料浸泡于含Ti ²⁺、In ³⁺、Sn ⁴⁺、Zn ²⁺、Al ³⁺、Ca ²⁺、Mg ²⁺、Zr ⁴⁺、ZrO ₃ ^2-、F ^-、Y ³⁺和硼酸根中的至少一种的溶液中，液相处理条件为25-90℃处理1-36h，获得预处理的电池层状正极材料； ⁽ ^b ⁾ Liquid ^- phase solution ^pretreatment ^, including ^soaking conventional ^lithium -ion battery cathode materials in In a solution of at least one of ⁺ , ZrO ₃ ^2- , F ^- , Y ³⁺ and borate, the liquid phase treatment condition is 25-90°C for 1-36 hours to obtain a pretreated battery layered positive electrode material;

步骤二，将步骤一获得的预处理的电池层状正极材料，在惰性气氛或还原性气氛下，300-700℃烧结1-24h，自然降温，即获得晶体结构的表面界面具有无机化合物层的锂离子电池正极材料。Step 2: Sinter the pretreated battery layered cathode material obtained in Step 1 at 300-700°C for 1-24 hours in an inert atmosphere or a reducing atmosphere, and cool down naturally to obtain a crystal structure with an inorganic compound layer on the surface interface Lithium-ion battery cathode material.
根据权利要求7所述的制备方法，其特征在于：所述惰性气氛为N ₂和/或Ar；所述还原性气氛为N ₂加H ₂的气氛，或者Ar加H ₂的气氛。 The preparation method according to claim 7, characterized in that: the inert atmosphere is _N2 and/or Ar; the reducing atmosphere is an atmosphere of _N2 plus _H2 , or an atmosphere of Ar plus _H2 .
根据权利要求1-6任一项所述的锂离子电池正极材料在制备动力电池、大规模储能电池，或3C消费电子产品、无人机或电子烟的锂离子电池中的应用。The application of the lithium ion battery positive electrode material according to any one of claims 1-6 in the preparation of power batteries, large-scale energy storage batteries, or lithium ion batteries for 3C consumer electronics products, unmanned aerial vehicles or electronic cigarettes.
一种采用权利要求1-6任一项所述的锂离子电池正极材料的锂离子电池。A lithium ion battery adopting the lithium ion battery cathode material described in any one of claims 1-6.