A confined structure ternary precursor, ternary material, and their preparation methods and applications

Abstract

The present invention belongs to the technical field of batteries, and discloses a confined structure ternary precursor, a ternary material, and their preparation methods and applications. The preparation method of the confined structure ternary precursor includes: firstly, introducing a +6-valent element in the nucleation stage of the precursor to induce the formation of crystal nuclei, and then sequentially changing the reaction conditions to introduce +5-valent, +4-valent, +3-valent, and +2-valent elements in the crystal nucleus growth stage. The introduced +6-valent element can induce the formation of crystal nuclei, making the nucleation process controllable, and the ions confined in the crystal nucleus growth stage can regulate the internal density of the precursor, relieve the stress caused by the structural contraction during the lithium ion extraction and insertion in the charge and discharge process, and improve the structural stability of the material during the cycling process. The present invention also provides a confined structure ternary material and its preparation method; as well as the applications of the confined structure ternary precursor and ternary material in lithium ion batteries or supercapacitors.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and particularly relates to a confined structure ternary precursor, a ternary material, and a preparation method and application thereof. Background Art

[0002] Achieving sustainable development and a zero-carbon future critically depends on the use of carbon-free energy sources such as renewable energy and electric vehicles charged by renewable electricity. However, the widespread deployment of renewable energy and the entry of electric vehicles into the energy market require efficient and low-cost energy storage technologies to compensate for the intermittency of renewable energy generation. Among all types of energy storage technologies, fast-response, high-energy-density, and modular electrochemical batteries stand out as one of the best options for addressing major energy storage challenges. Lithium batteries are regarded as one of the most promising battery technologies and are currently used in electric vehicles and have been considered for large-scale renewable energy storage applications. Unfortunately, low energy density, limited lithium and cobalt resources, high cost, and safety issues have greatly restricted the application of lithium-ion batteries in the field of large-scale clean energy. In recent decades, improving energy density and using widely available materials have been considered the top priorities in lithium-ion battery research, and the cathode material is the key material determining the battery's energy density. Therefore, there is an urgent need to develop a cathode material with high energy density, low cost, and high safety.

[0003] In recent years, LiMO 2 (M = Co, Mn, and Ni) layered oxides have been the cathode choice for modern lithium-ion battery technology. Because the two-dimensional layered structure is suitable for the insertion / storage of lithium ions, and transition metal (TM) ions can change their oxidation states to maintain electrical neutrality. LiCoO 2 was the first cathode material used in commercial lithium-ion batteries. However, concerns about cobalt cost and limited resources have triggered a new direction in the search for alternative layered LiMO 2 cathodes in recent years. A promising class of high-nickel and low-cobalt LiNi x Co y Mn 1-x-y O 2 (x≥0.6, denoted as NCM) materials have become alternatives to LiCoO 2 , and NCM has a higher working voltage and energy density, as well as lower cost than LiCoO 2 . However, during charge and discharge, due to Li +Due to the mutual migration between lithium ions and transition metal (TM) ions, phase degradation from a layered structure to a rock-salt structure usually occurs on the surface of the NCM electrode. At the same time, due to the different crystallization orientations of primary particles and the continuous change of crystal volume caused by anisotropy in the crystal, intergranular cracks are likely to occur, exacerbating interfacial side reactions and conductivity hysteresis. Ion doping is an effective and simple optimization strategy that can effectively adjust the crystal structure of high-nickel layered oxides and improve structural stability. However, the secondary doping scheme has problems such as uneven element distribution and segregation caused by low solubility of some elements in the NCM material, resulting in insignificant modification effects and poor material consistency, thus causing instability in battery performance. Summary of the Invention

[0004] Embodiments of the present invention provide a confined-structure ternary precursor, a ternary material, and their preparation methods and applications, aiming to solve the problems in the prior art such as uneven distribution of dopants in the cathode material, resulting in poor material consistency, irreversible phase transformation on the surface caused by the migration of transition metal ions during cycling, and structural instability.

[0005] The preparation method of a confined-structure ternary precursor according to an embodiment of the present invention includes the following steps:

[0006] Synthesize the ternary precursor by the co-precipitation method. In the nucleation stage of the grooved reaction, introduce a +6-valent element under the first reaction conditions to obtain uniformly sized crystal nuclei.

[0007] After the formation of the crystal nuclei, change the reaction conditions to the second reaction conditions, and introduce a +5-valent element while maintaining the introduction of the +6-valent element.

[0008] Change the reaction conditions to the third reaction conditions, and introduce a +4-valent element while maintaining the introduction of the +6-valent and +5-valent elements.

[0009] Change the reaction conditions to the fourth reaction conditions, and introduce a +3-valent element while maintaining the introduction of the +6-valent, +5-valent, and +4-valent elements.

[0010] Change the reaction conditions to the fifth reaction conditions, and introduce a +2-valent element while maintaining the introduction of the +6-valent, +5-valent, +4-valent, and +3-valent elements to obtain a confined-structure ternary precursor.

[0011] Preferably, the reaction conditions of the confined-structure ternary precursor are changed from the core to the surface layer, introducing +6-valent, +5-valent, +4-valent, +3-valent, and +2-valent elements, and the ionic valence states of the elements also show a confined decrease, forming a confined increase of ions from one to five from the core to the surface layer.

[0012] Preferably, the first reaction conditions are a stirring speed of 200 - 500 r / min and a pH of 11 - 13.5; the second reaction conditions are a stirring speed of 200 - 460 r / min and a pH of 11 - 13.2; the third reaction conditions are a stirring speed of 220 - 430 r / min and a pH of 10.8 - 13.2; the fourth reaction conditions are a stirring speed of 220 - 400 r / min and a pH of 10.5 - 13; the fifth reaction conditions are a stirring speed of 240 - 380 r / min and a pH of 10 - 13.

[0013] Preferably, among the entropy - increasing elements, the proportions of the +6 - valent element, the +5 - valent element, the +4 - valent element, the +3 - valent element, and the +2 - valent element are each controlled within 10 - 30%.

[0014] Preferably, the +6 - valent element is at least one of W, Mo, or Cr; the +5 - valent element is at least one of V, Nb, or Ta; the +4 - valent element is at least one of Ti, Zr, or Ce; the +3 - valent element is at least one of La, Al, Sc, or Y; the +2 - valent element is at least one of Mg, Cu, or Ca.

[0015] Preferably, during the preparation process of the confined - structure ternary precursor, the particle size of the precursor increases by 0.5 - 5 μm under each reaction condition, that is, the thickness of each layer is 0.5 - 5 μm.

[0016] Preferably, the +6 - valent element, +5 - valent element, +4 - valent element, +3 - valent element, and +2 - valent element are introduced in the form of one or more of the corresponding element nitrates, sulfates, acetates, chlorides, phosphates, or carbonates.

[0017] Preferably, in the above - mentioned confined - structure ternary precursor, the chemical general formula of the ternary precursor is Ni x Co y Mn z (OH) 2 , where 0.88 ≤ x ≤ 0.98, 0.01 ≤ y ≤ 0.11, 0.01 ≤ z ≤ 0.11, and x + y+z = 1. The ternary precursor is a high - nickel precursor.

[0018] In the preparation method of the confined structure ternary precursor, a co-precipitation method is used to synthesize the precursor. A +6-valent element is introduced in the nucleation stage of the slotted reaction to form uniformly sized crystal nuclei; a +5-valent element is introduced after the formation of the crystal nuclei to promote the growth of the crystal nuclei; then a +4-valent element is introduced in the particle growth stage to form a dense sandwich structure; after the particle size grows to a certain extent, a +3-valent element is introduced to form a loose stress release layer; finally, a +2-valent element is introduced during the formation of the outer surface layer to form a dense electrolyte barrier layer until the reaction ends. The types of elements introduced in the confined structure ternary precursor increase from one confinement to five from the core to the surface layer, and the valence states of the introduced elements decrease from +6-valent confinement to +2-valent. The synergistic effect of different valence state elements can regulate the internal charge balance, stabilize the lattice oxygen, and reduce the dissolution of transition metals caused by the release of lattice oxygen.

[0019] An embodiment of the present invention also provides a confined structure ternary precursor, and the confined structure ternary precursor is obtained by the above preparation method.

[0020] Preferably, the particle size of the confined structure ternary precursor is 3 - 20 μm.

[0021] The confined structure ternary precursor obtained by the above preparation can be used to prepare a confined structure ternary material.

[0022] The present invention also provides a preparation method of a confined structure ternary material, including the following steps:

[0023] Mix the confined structure ternary precursor obtained by the above preparation with a lithium source in an amount 1 - 10% in excess, and perform high-temperature sintering to obtain a confined structure ternary material.

[0024] Preferably, the temperature and time of the high-temperature sintering are: sinter at 400 - 600 °C for 2 - 6 hours, and then sinter at 600 - 900 °C for 10 - 20 hours, where the heating rate is 1 - 5 °C / min.

[0025] Preferably, the lithium source is one or more of lithium hydroxide, lithium fluoride, lithium sulfide, lithium carbonate, lithium phosphate, or lithium dihydrogen phosphate.

[0026] In the preparation method of the ternary material, it is obtained by mixing and sintering the above-mentioned confined structure ternary precursor with a lithium source. During the sintering process, the elements introduced by confinement will diffuse short-range to adjacent layers, playing a confinement role, improving the lithium ion transmission speed at the junction of layers, and reducing the cracking phenomenon of spherical particles caused by uneven lithium concentration distribution, thereby improving the cycle stability of the confined structure ternary material.

[0027] An embodiment of the present invention also provides a confined structure ternary material, and the confined structure ternary material is obtained by the above preparation method.

[0028] The embodiments of the present invention also provide the applications of the above-confined structure ternary precursor and the above-confined structure ternary material, and the above-confined structure ternary precursor and the above-confined structure ternary material are applied to lithium-ion batteries or supercapacitors.

[0029] The beneficial effects achieved by the present invention are as follows: In the preparation process of the confined structure ternary precursor in the embodiments of the present invention, a +6-valent element is first introduced in the nucleation stage of the precursor to induce the formation of crystal nuclei, and then the reaction conditions are sequentially changed to introduce +5-valent, +4-valent, +3-valent, and +2-valent elements in the crystal nucleus growth stage. The introduced +6-valent element can induce the formation of crystal nuclei, making the nucleation process controllable, and the ions confined in the crystal nucleus growth stage can regulate the internal density of the precursor, relieve the stress caused by the structural contraction during the lithium-ion deintercalation and intercalation processes during charge and discharge, and improve the structural stability of the material during the cycling process. Moreover, the limited decrease in ion valence can regulate the charge and form a high-entropy material on the surface, which can inhibit the release of oxygen during the cycling process of the ultra-high nickel material and improve the stability of the material.

[0030] In the preparation process of the confined structure ternary material in the embodiments of the present invention, the above-confined structure ternary precursor is first mixed with a lithium source and subjected to high-temperature sintering in an oxygen atmosphere to prepare an ultra-high nickel cathode material with a radial distribution of entropy-increasing elements and high internal density. The density difference regulated by the entropy-increasing elements relieves the stress during the lithium-ion deintercalation process, so that the high-nickel cathode material has a long cycle life and improved safety. At the same time, the particle cracking caused by stress is reduced, the erosion of the spherical particle interior by the electrolyte is avoided, the interfacial side reactions are reduced, and the surface irreversible phase transformation is inhibited to a certain extent. Description of the Drawings

[0031] Figure 1 Schematic diagram of the confined structure ternary precursor.

[0032] Figure 2 Confined structure LiNi 0.98 Co 0.01 Mn 0.01 O 2 1C rate cycling diagram of the cathode material.

[0033] Figure 3 Confined structure LiNi 0.98 Co 0.01 Mn 0.01 O 2 dQ / dV diagram of the cathode material.

[0034] Figure 4 Confined structure LiNi 0.98 Co 0.01 Mn 0.01 O 2Rate performance chart of the cathode material.

[0035] Figure 5 Confined structure LiNi 0.96 Co 0.02 Mn 0.02 O 2 FIB cross-sectional morphology chart of the cathode material.

[0036] Figure 6 Multi-particle doped LiNi 0.96 Co 0.02 Mn 0.02 O 2 FIB cross-sectional morphology chart of the cathode material.

[0037] Figure 7 Confined structure and multi-particle modified LiNi 0.96 Co 0.02 Mn 0.02 O 2 1C cycle chart of the cathode material.

[0038] Figure 8 Confined structure and multi-particle modified LiNi 0.96 Co 0.02 Mn 0.02 O 2 EIS chart of the cathode material.

[0039] Figure 9 Confined structure LiNi 0.96 Co 0.02 Mn 0.02 O 2 XRD refined chart of the cathode material.

[0040] Figure 10 Confined structure and Mo modified LiNi 0.96 Co 0.02 Mn 0.02 O 2 1C cycle chart of the cathode material.

[0041] Figure 11 Confined structure and Nb modified LiNi 0.96 Co 0.02 Mn 0.02 O 2 1C cycle chart of the cathode material.

[0042] Figure 12 Confined structure and Zr modified LiNi 0.96 Co 0.02 Mn 0.02 O 2 1C cycle chart of the cathode material.

[0043] Figure 13 Confined structure and Al-modified LiNi 0.96 Co 0.02 Mn 0.02 O 2 1C cycling graph of the cathode material.

[0044] Figure 14 Confined structure and Mg-modified LiNi 0.96 Co 0.02 Mn 0.02 O 2 1C cycling graph of the cathode material.

[0045] Figure 15 Confined structure LiNi 0.90 Co 0.05 Mn 0.05 O 2 1C rate cycling graph of the cathode material.

[0046] Figure 16 Confined structure LiNi 0.90 Co 0.05 Mn 0.05 O 2 Rate graph of the cathode material.

[0047] Figure 17 Confined structure LiNi 0.90 Co 0.05 Mn 0.05 O 2 GITT graph of the cathode material.

[0048] Figure 18 Confined structure LiNi 0.88 Co 0.06 Mn 0.06 O 2 Cycling graph of the full cell assembled with the cathode material.

[0049] Figure 19 Confined structure LiNi 0.88 Co 0.06 Mn 0.06 O 2 Median voltage graph of the full cell assembled with the cathode material. Detailed implementation manners

[0050] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0051] An embodiment of the present invention provides a method for preparing a confined structure ternary (ultra-high nickel) precursor. The preparation method includes the following steps:

[0052] Synthesize a ternary (ultra-high nickel) precursor by coprecipitation. During the nucleation stage of the slotted reaction, introduce a +6-valent element to obtain uniformly sized crystal nuclei.

[0053] After the crystal nuclei are formed, change the reaction conditions and introduce a +5-valent element while maintaining the introduction of the +6-valent element.

[0054] Change the reaction conditions again and introduce a +4-valent element while maintaining the introduction of the +6-valent and +5-valent elements.

[0055] Change the reaction conditions again and introduce a +3-valent element while maintaining the introduction of the +6-valent, +5-valent, and +4-valent elements.

[0056] Change the reaction conditions again and introduce a +2-valent element while maintaining the introduction of the +6-valent, +5-valent, +4-valent, and +3-valent elements to obtain a confined structure ternary precursor.

[0057] Specifically, as Figure 1 shown, the method for preparing the confined structure ternary precursor is to introduce a +6-valent element during the nucleation stage of synthesizing the precursor by coprecipitation to induce the formation of crystal nuclei. At the end of the nucleation stage, when the crystal nuclei begin to grow, while continuously introducing the +6-valent element, change the reaction conditions in sequence to introduce the +5-valent, +4-valent, +3-valent, and +2-valent elements. The synergistic effect of multiple elements can regulate particle growth, control the particle size and morphology, and prepare a confined structure ternary precursor. The particle diameter of the precursor is 3 - 20 μm.

[0058] In an optional embodiment, the stirring speed of the reaction when introducing the +6-valent element is 200 - 500 r / min, the stirring speed of the reaction when introducing the +5-valent element is 200 - 460 r / min, the stirring speed of the reaction when introducing the +4-valent element is 220 - 430 r / min, the stirring speed of the reaction when introducing the +3-valent element is 220 - 400 r / min, and the stirring speed of the reaction when introducing the +2-valent element is 240 - 380 r / min.

[0059] Optionally, the stirring speed during the reaction when introducing the +6 valence element can be 200 r / min, 240 r / min, 290 r / min, 360 r / min, 420 r / min, 460 r / min, 500 r / min or any value between 200 and 500 r / min; the stirring speed during the reaction when introducing the +5 valence element can be 200 r / min, 260 r / min, 280 r / min, 320 r / min, 470 r / min, 420 r / min, 460 r / min or any value between 200 and 460 r / min; the stirring speed during the reaction when introducing the +4 valence element can be 220 r / min, 270 r / min, 300 r / min, 340 r / min, 370 r / min, 400 r / min, 430 r / min or any value between 220 and 430 r / min; the stirring speed during the reaction when introducing the +3 valence element can be 220 r / min, 270 r / min, 320 r / min, 365 r / min, 380 r / min, 400 r / min or any value between 220 and 400 r / min; the stirring speed during the reaction when introducing the +2 valence element can be 240 r / min, 270 r / min, 310 r / min, 330 r / min, 360 r / min, 380 r / min or any value between 240 and 380 r / min.

[0060] In an optional embodiment, the pH during the reaction when introducing the +6 valence element is 11 - 13.5; the pH during the reaction when introducing the +5 valence element is 11 - 13.2; the pH during the reaction when introducing the +4 valence element is 10.8 - 13.2; the pH during the reaction when introducing the +3 valence element is 10.5 - 13; the pH during the reaction when introducing the +2 valence element is 10 - 13.

[0061] Optionally, the pH value during the reaction when introducing the +6-valence element can be 11, 11.4, 11.7, 12, 12.4, 12.9, 13.2, 13.5, or any value between 11 and 13.5; the pH value during the reaction when introducing the +5-valence element can be 11, 11.3, 11.8, 12, 12.3, 12.8, 13, 13.2, or any value between 11 and 13.2; the pH value during the reaction when introducing the +4-valence element can be 10.8, 11.2, 11.5, 11.8, 12.2, 12.5, 12.8, 13, 13.2, or any value between 10.8 and 13.2; the pH value during the reaction when introducing the +3-valence element can be 10.5, 10.8, 11.2, 11.5, 11.8, 12.2, 12.5, 12.8, 13, or any value between 10.5 and 13; the pH value during the reaction when introducing the +2-valence element can be 10, 10.3, 10.5, 10.8, 11.2, 11.5, 11.8, 12.2, 12.5, 12.8, 13, or any value between 10 and 13.

[0062] In an alternative embodiment, the +6-valence element is at least one of W, Mo, or Cr; the +5-valence element is at least one of V, Nb, or Ta; the +4-valence element is at least one of Ti, Zr, or Ce; the +3-valence element is at least one of La, Al, Sc, or Y; and the +2-valence element is at least one of Mg, Cu, or Ca.

[0063] In an alternative embodiment, during the preparation process of the confined structure ternary (ultra-high nickel) precursor, the particle size of the precursor increases by 0.5 - 5 μm under each reaction condition.

[0064] Optionally, when introducing a +6-valent element, the precursor particle size can increase by 0.5 μm, 0.8 μm, 1 μm, 1.6 μm, 2.5 μm, 3.4 μm, 4.2 μm, 4.8 μm, 5 μm, or any value between 0.5 and 5 μm. When introducing a +5-valent element, the precursor particle size can increase by 0.5 μm, 0.7 μm, 1.2 μm, 1.8 μm, 2.4 μm, 3.5 μm, 4 μm, 4.6 μm, 5 μm, or any value between 0.5 and 5 μm. When introducing a +4-valent element, the precursor particle size can increase by 0.5 μm, 0.8 μm, 1.1 μm, 1.7 μm, 2.7 μm, 3.6 μm, 4.1 μm, 4.7 μm, 5 μm, or any value between 0.5 and 5 μm. When introducing a +3-valent element, the precursor particle size can increase by 0.5 μm, 0.7 μm, 1 μm, 1.6 μm, 2.5 μm, 3.0 μm, 4.0 μm, 4.5 μm, 5 μm, or any value between 0.5 and 5 μm. When introducing a +2-valent element, the precursor particle size can increase by 0.5 μm, 0.8 μm, 1.2 μm, 1.9 μm, 2.6 μm, 3.5 μm, 4.3 μm, 4.7 μm, 5 μm, or any value between 0.5 and 5 μm.

[0065] In an optional embodiment, the proportions of the +6-valent, +5-valent, +4-valent, +3-valent, and +2-valent elements in the total entropy-increasing elements are each controlled at about 10 - 30%.

[0066] Optionally, the proportion of the +6-valent element can be 10%, 13%, 18%, 20%, 25%, 30%, or any value between 10 and 30%. The proportion of the +5-valent element can be 10%, 12%, 15%, 22%, 28%, 30%, or any value between 10 and 30%. The proportion of the +4-valent element can be 10%, 13%, 15%, 18%, 24%, 30%, or any value between 10 and 30%. The proportion of the +3-valent element can be 10%, 15%, 18%, 22%, 27%, 30%, or any value between 10 and 30%. The proportion of the +2-valent element can be 10%, 12%, 16%, 21%, 26%, 30%, or any value between 10 and 30%.

[0067] In an optional embodiment, in the confined structure ternary precursor, the chemical general formula of the ternary precursor is Ni x Co y Mn z (OH) 2 , where 0.88 ≤ x ≤ 0.98, 0.01 ≤ x ≤ 0.11, 0.01 ≤ x ≤ 0.11, and x + y + z = 1.

[0068] In an optional embodiment, the particle size of the confined structure ternary precursor is 3-20 μm.

[0069] Optionally, the particle size of the precursor can be 3 μm, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm or any value between 3-20 μm.

[0070] The present invention also provides a method for preparing a confined structure ternary material, comprising the following steps:

[0071] Mix the above-prepared confined structure ternary precursor with a lithium source and perform high-temperature sintering to obtain a confined structure ternary material.

[0072] In an optional embodiment, the confined structure ternary precursor is mixed with a lithium source and obtained by high-temperature sintering in an oxygen atmosphere. The sintering temperature and time are 2-6 hours at 400-600 °C, and then 10-20 hours at 600-900 °C, where the heating rate is 1-5 °C / min.

[0073] Optionally, the first-stage sintering temperature can be 400 °C, 440 °C, 500 °C, 560 °C, 600 °C or any value between 400-600 °C, the first-stage sintering time can be 2 hours, 2.5 hours, 3.6 hours, 4 hours, 5.2 hours, 6 hours or any value between 2-6 hours, the second-stage sintering temperature can be 600 °C, 660 °C, 700 °C, 760 °C, 820 °C, 900 °C or any value between 600-900 °C, and the second-stage sintering time can be 10 hours, 12.5 hours, 15 hours, 16 hours, 18 hours, 20 hours or any value between 10-20 hours.

[0074] Optionally, the lithium source is one or more of lithium hydroxide, lithium fluoride, lithium sulfide, lithium carbonate, lithium phosphate or lithium dihydrogen phosphate.

[0075] During the battery cycling process, lithium ions are repeatedly inserted and extracted in the high-nickel cathode material. When lithium ions are extracted from and inserted into the high-nickel cathode material, the layer spacing of the high-nickel material changes, and certain stress and strain will be generated during this process. With the accumulation of time, the spherical particles of the material will undergo stress cracking, which will increase the contact area between the material and the electrolyte and intensify the side reactions on the surface, ultimately leading to battery cycling failure. Therefore, in this embodiment, a confined structure high-nickel cathode material is designed. The density of this material shows a confined distribution, which can release the stress generated during the lithium ion insertion and extraction process, avoid stress cracking of the material, and thus improve the cycling stability and safety of the material.

[0076] The following uses multiple specific examples to illustrate an embodiment of the present invention, a confined structure ternary precursor, a ternary material (ultra-high nickel cathode material), and its preparation method and application, etc.

[0077] Example 1

[0078] This embodiment provides a preparation method for a confined structure ternary precursor, which is prepared according to the following steps:

[0079] Apply the co-precipitation method to synthesize Ni 0.98 Co 0.01 Mn 0.01 (OH) 2 precursor. In the nucleation stage of the slotted reaction, adjust the rotation speed of the reaction kettle to 480 r / min, adjust the pH to 13.2, and introduce 0.5 wt% of tungsten nitrate at the same time to obtain uniformly sized crystal nuclei;

[0080] When the crystal nuclei are formed, adjust the rotation speed of the reaction kettle to 450 r / min, adjust the pH to 13.0, and introduce 0.8 wt% of niobium nitrate;

[0081] Then adjust the rotation speed of the reaction kettle to 430 r / min, adjust the pH to 13.0, and introduce 1 wt% of zirconium nitrate;

[0082] Then adjust the rotation speed of the reaction kettle to 400 r / min, adjust the pH to 12.8, and introduce 1.2 wt% of lanthanum nitrate;

[0083] Then adjust the rotation speed of the reaction kettle to 380 r / min, adjust the pH to 12.6, and introduce 1.2 wt% of magnesium nitrate until the reaction ends, and finally prepare a confined structure Ni 0.98 Co 0.01 Mn 0.01 (OH) 2 precursor.

[0084] Weigh 3 g of the confined structure Ni 0.98 Co 0.01 Mn 0.01 (OH) 2 precursor in Example 1 and mix it with 1.386 g of LiOH·H 2 O. Under an oxygen atmosphere, heat it to 400 °C at a heating rate of 3 °C / min and hold for 4 h, then heat it to 700 °C at a heating rate of 3 °C / min and hold for 15 h, and cool it to room temperature with the furnace to obtain a confined structure LiNi 0.98 Co 0.01 Mn 0.01 O 2 cathode material.

[0085] The prepared confined structure LiNi 0.98 Co 0.01 Mn 0.01 O 2 cathode material is assembled with electrolyte, lithium sheet and other necessary battery components into a CR2016 type button battery. The charge-discharge capacity of the battery prepared in this example is tested: the charge-discharge test is carried out in an environment of 25 °C, and the test voltage range of the CR2016 type button battery is 3.0 - 4.3V. The discharge specific capacity at 1C is as high as 22.3 mAh / g, and after 200 cycles, the capacity retention rate is as high as 85%, as Figure 2 shown, and through the analysis of the capacity differential curve, it is found that after 200 cycles, its redox peaks still remain very complete, as Figure 3 shown. Its rate performance is tested, as Figure 4 shown, at a rate of 10C, the discharge specific capacity of the confined structure LiNi 0.98 Co 0.01 Mn 0.01 O 2 cathode material is close to 180 mAh / g, which is much higher than the discharge capacity of the sample in Comparative Example 1.

[0086] Example 2

[0087] This example provides a preparation method of a confined structure ternary (high nickel) precursor, which is prepared according to the following steps:

[0088] Using the co-precipitation method to synthesize Ni 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor. In the nucleation stage of the grooved reaction, the rotation speed of the reaction kettle is adjusted to 460 r / min, the pH is adjusted to 13.0, and 1 wt% molybdenum nitrate is introduced at the same time to obtain uniformly sized crystal nuclei;

[0089] When the crystal nuclei are formed, the rotation speed of the reaction kettle is adjusted to 450 r / min, the pH is adjusted to 13.0, and 1 wt% niobium nitrate is introduced;

[0090] Then the rotation speed of the reaction kettle is adjusted to 430 r / min, the pH is adjusted to 12.8, and 1.2 wt% tetrabutyl titanate is introduced;

[0091] Then the rotation speed of the reaction kettle is adjusted to 400 r / min, the pH is adjusted to 12.5, and 1.5 wt% aluminum nitrate is introduced;

[0092] Adjust the rotation speed of the reactor to 380 r / min, adjust the pH to 12.5, and introduce 1.5 wt% magnesium sulfate until the reaction ends, finally preparing a confined structure Ni containing Mo, Nb, Ti, Al, and Mg elements 0.96 Co 0.02 Mn 0.02 (OH) 2 Precursor

[0093] Weigh 1 g of the Ni 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor prepared in Example 2 and mix it with 0.4851 g of LiOH·H 2 O. Heat it from room temperature to 400 °C at a heating rate of 3 °C / min under an oxygen atmosphere and hold for 5 h, then heat it to 730 °C at a heating rate of 3 °C / min and hold for 15 h, and then cool it to room temperature in the furnace to obtain the confined structure Li Ni 0.96 Co 0.02 Mn 0.02 O 2 cathode material, and its cross-sectional morphology is as shown in Figure 5 shown

[0094] Assemble the prepared confined structure LiNi 0.96 Co 0.02 Mn 0.02 O 2 cathode material with electrolyte, lithium sheet, and other necessary battery components into a CR2016 type button battery. Conduct charge-discharge capacity tests on the battery prepared in this example: conduct charge-discharge tests in a 25 °C environment, and the test voltage range of the CR2016 type button battery is 3.0 - 4.3 V. The discharge specific capacity at 0.1 C is as high as 238 mAh / g, the discharge specific capacity at 1 C is 215.6 mAh / g, and the reversible capacity after 300 cycles is 187 mAh / g, and the capacity retention rate is as high as 86.9%, as shown in Figure 7 shown. Conduct impedance tests on the assembled button battery and find that the impedance of the confined structure LiNi 0.96 Co 0.02 Mn 0.02 O 2 cathode material is significantly lower than that of the material in Comparative Example 2, as shown in Figure 8 shown. Conduct XRD diffraction analysis on the confined structure Li N i 0.93 Co 0.03 Mn 0.04 O 2 cathode material and find that the ratio of (003) to (104) is as high as 1.56, indicating that L i N i 0.96 Co 0.02 Mn0.02 O 2 The degree of lithium-nickel mixing in the cathode material is relatively low, as Figure 9 shown. Then, the confined structure LiNi 0.96 Co 0.02 Mn 0.02 O 2 cathode material is compared with the material doped with a single element in terms of electrical properties as Figures 10 - 14 shown. The cycle stability of the confined structure material is significantly better than that of the material modified by doping with a single element.

[0095] Example 3

[0096] This embodiment provides a preparation method of a confined structure ternary (high nickel) precursor, which is prepared according to the following steps:

[0097] Using the co-precipitation method to synthesize Ni 0.90 Co 0.05 Mn 0.05 (OH) 2 precursor. In the nucleation stage of the grooved reaction, the rotation speed of the reaction kettle is adjusted to 450 r / min, the pH is adjusted to 13.0, and 0.8 wt% molybdenum nitrate is introduced at the same time to obtain uniformly sized crystal nuclei;

[0098] When the crystal nuclei are formed, the rotation speed of the reaction kettle is adjusted to 450 r / min, the pH is adjusted to 12.8, and 1 wt% tantalum nitrate is introduced;

[0099] Then, the rotation speed of the reaction kettle is adjusted to 430 r / min, the pH is adjusted to 12.6, and 1.2 wt% cerium nitrate is introduced;

[0100] Then, the rotation speed of the reaction kettle is adjusted to 400 r / min, the pH is adjusted to 12.5, and 1.5 wt% aluminum sulfate is introduced;

[0101] Then, the rotation speed of the reaction kettle is adjusted to 380 r / min, the pH is adjusted to 12.5, and 1.5 wt% calcium nitrate is introduced until the reaction ends, and finally a confined structure Ni 0.90 Co 0.05 Mn 0.05 (OH) 2 precursor containing Mo, Ta, Ce, Al and Ca elements is prepared.

[0102] Weigh 5 g of the confined structure Ni 0.90 Co 0.05 Mn 0.05 (OH) 2 precursor in Example 3 and 2.29 g of LiOH·H 2Mix them, heat them up to 500 °C at a heating rate of 3 °C / min in an oxygen atmosphere and hold for 5 h, then heat them up to 760 °C at a heating rate of 3 °C / min and hold for 15 h, and cool them to room temperature in the furnace to obtain the confined structure LiNi 0.90 Co 0.05 Mn 0.05 O 2 cathode material.

[0103] Assemble the prepared confined structure LiNi 0.90 Co 0.05 Mn 0.05 O 2 cathode material with electrolyte, lithium sheet and other necessary battery components into a CR2016 type button battery. Conduct charge-discharge capacity test on the battery prepared in this example: conduct charge-discharge test in an environment of 25 °C, and the test voltage range of the CR2016 type button battery is 3.0 - 4.3 V. The discharge specific capacity at 1C rate is as high as 208 mAh / g, and the reversible capacity is 196.3 mAh / g after 100 cycles, and the capacity retention rate is as high as 94.3%, as Figure 15 shown. Conduct rate performance test on it, as Figure 16 shown, the reversible capacity of the confined structure LiNi 0.90 Co 0.05 Mn 0.05 O 2 cathode material is 170 mAh / g at 10C rate, which is much higher than the material of Comparative Example 3. And conduct constant current intermittent titration technique analysis on the two materials, as Figure 17 shown. It is found by comparison that the lithium ion diffusion rate of the confined structure LiNi 0.90 Co 0.05 Mn 0.05 O 2 cathode material is as high as 4.2×10 -9 , while that of the comparative example sample is only 1.7×10 -10 .

[0104] Example 4

[0105] This example provides a preparation method of a confined structure ternary (high nickel) precursor, which is prepared according to the following steps:

[0106] Synthesize Ni 0.88 Co 0.06 Mn 0.06 (OH) 2 precursor by coprecipitation method. In the nucleation stage of the grooved reaction, adjust the rotation speed of the reaction kettle to 420 r / min, adjust the pH to 12.8, and introduce 1 wt% of tungsten nitrate at the same time to obtain uniformly sized crystal nuclei;

[0107] When the crystal nucleus is formed, the rotation speed of the reaction kettle is adjusted to 400 r / min, the pH is adjusted to 12.6, and 1 wt% tantalum nitrate is introduced;

[0108] Then, the rotation speed of the reaction kettle is adjusted to 400 r / min, the pH is adjusted to 12.5, and 1.4 wt% cerium sulfate is introduced;

[0109] Then, the rotation speed of the reaction kettle is adjusted to 360 r / min, the pH is adjusted to 12.2, and 1.8 wt% aluminum sulfate is introduced;

[0110] Then, the rotation speed of the reaction kettle is adjusted to 350 r / min, the pH is adjusted to 12.2, and 2 wt% magnesium chloride is introduced until the reaction ends, and finally a confined structure Ni 0.88 Co 0.06 Mn 0.06 (OH) 2 precursor is prepared.

[0111] Weigh 30 kg of the confined structure Ni 0.88 Co 0.06 Mn 0.06 (OH) 2 precursor obtained in Example 4 and mix it with 13.86 kg of LiOH·H 2 O. Heat it from room temperature to 570 °C at a heating rate of 3 °C / min in an oxygen atmosphere and hold for 4 h, then heat it to 800 °C at a heating rate of 3 °C / min and hold for 15 h, and then cool it to room temperature with the furnace to obtain the confined structure LiNi 0.88 Co 0.06 Mn 0.06 O 2 cathode material.

[0112] Apply the prepared confined structure LiNi 0.88 Co 0.06 Mn 0.06 O 2 cathode material to match with a graphite anode to assemble a 18650-type full cell. The designed capacity of the full cell is 2500 mAh. It has an initial discharge capacity of 2352 mAh at a 2C rate. After 1000 cycles, there is still a discharge capacity of 2034 mAh, and the capacity retention rate is 86.1%, as Figure 18 shown. Moreover, it is found by comparison that after 1000 cycles, the median voltage of the confined structure LiNi 0.88 Co 0.06 Mn 0.06 O 2 cathode material hardly decays, as Figure 19 shown.

[0113] Comparative Example 1

[0114] Prepare Ni without introducing doping elements under the conditions of Example 1 0.98 Co 0.01 Mn 0.01 (OH) 2 precursor, and sinter and test it under the conditions of Example 1

[0115] Comparative Example 2

[0116] This comparative example provides a preparation method of a multi-element doped high-nickel precursor, which is prepared according to the following steps:

[0117] Synthesize Ni using the coprecipitation method 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor. During the nucleation stage of the grooved reaction, adjust the rotation speed of the reaction kettle to 460 r / min, adjust the pH to 13.0, and introduce 1 wt% molybdenum nitrate at the same time to obtain uniformly sized crystal nuclei;

[0118] When the crystal nuclei are formed, adjust the rotation speed of the reaction kettle to 450 r / min, adjust the pH to 13.0, stop feeding molybdenum nitrate, and introduce 1 wt% zirconium nitrate;

[0119] Then adjust the rotation speed of the reaction kettle to 430 r / min, adjust the pH to 12.8, stop feeding zirconium nitrate, and introduce 1.2 wt% tetrabutyl titanate;

[0120] Then adjust the rotation speed of the reaction kettle to 430 r / min, adjust the pH to 12.5, stop feeding tetrabutyl titanate, and introduce 1.5 wt% aluminum nitrate;

[0121] Then adjust the rotation speed of the reaction kettle to 420 r / min, adjust the pH to 12.5, stop feeding aluminum nitrate, and introduce 1.5 wt% lanthanum nitrate until the reaction ends, finally preparing a Ni 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor containing Mo, Zr, Ti, Al and La elements

[0122] Weigh 1 g of the Ni 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor in Comparative Example 2 and 0.4851 g of LiOH·H 2Mix with O, heat to 400 °C at a heating rate of 3 °C / min under an oxygen atmosphere and hold for 5 h, then heat to 730 °C at a heating rate of 3 °C / min and hold for 15 h, and cool to room temperature with the furnace to obtain Li Ni co-doped with Mo, Zr, Ti, Al and La 0.96 Co 0.02 Mn 0.02 O 2 cathode material, the cross-sectional morphology of which is as Figure 6 shown, and then the electrochemical performance test is carried out according to the conditions of Example 2.

[0123] Comparative Example 3

[0124] This comparative example provides a preparation method of a single-element doped high-nickel precursor and cathode material, which is prepared according to the following steps:

[0125] Apply the coprecipitation method to synthesize Ni 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor. In the nucleation stage of the slotted reaction, adjust the rotation speed of the reaction kettle to 430 r / min, adjust the pH to 13.0, and introduce 1 wt% molybdenum nitrate at the same time until the reaction ends, and finally prepare Ni containing Mo element 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor.

[0126] Weigh 1 g of the Ni containing Mo element in Comparative Example 3 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor and mix it with 0.4851 g of LiOH·H 2 O, heat to 400 °C at a heating rate of 3 °C / min under an oxygen atmosphere and hold for 5 h, then heat to 730 °C at a heating rate of 3 °C / min and hold for 15 h, and cool to room temperature with the furnace to obtain Mo-doped Li Ni 0.96 Co 0.02 Mn 0.02 O 2 cathode material, and then the electrochemical performance test is carried out according to the conditions of Example 2.

[0127] Comparative Example 4

[0128] This comparative example provides a preparation method of a single-element doped high-nickel precursor and cathode material, which is prepared according to the following steps:

[0129] Apply the coprecipitation method to synthesize Ni0.96 Co 0.02 Mn 0.02 (OH) 2 Precursor. During the nucleation stage of the slotting reaction, adjust the rotation speed of the reaction kettle to 430 r / min, adjust the pH to 13.0, and introduce 1 wt% niobium nitrate simultaneously until the reaction ends, and finally prepare Ni containing Nb element 0.96 Co 0.02 Mn 0.02 (OH) 2 Precursor

[0130] Weigh 1 g of the Ni containing Nb element in Comparative Example 4 0.96 Co 0.02 Mn 0.02 (OH) 2 Precursor and mix it with 0.4851 g of LiOH·H 2 O. Heat it to 400 °C at a heating rate of 3 °C / min in an oxygen atmosphere and hold for 5 h, then heat it to 730 °C at a heating rate of 3 °C / min and hold for 15 h, and cool it to room temperature with the furnace to obtain LiNi doped with Nb 0.96 Co 0.02 Mn 0.02 O 2 Positive electrode material, and then conduct electrochemical performance tests according to the conditions in Example 2

[0131] Comparative Example 5

[0132] This comparative example provides a preparation method of a single element doped high nickel precursor and positive electrode material, which is prepared according to the following steps

[0133] Synthesize Ni using the coprecipitation method 0.96 Co 0.02 Mn 0.02 (OH) 2 Precursor. During the nucleation stage of the slotting reaction, adjust the rotation speed of the reaction kettle to 430 r / min, adjust the pH to 13.0, and introduce 1 wt% zirconium nitrate simultaneously until the reaction ends, and finally prepare Ni containing Zr element 0.96 Co 0.02 Mn 0.02 (OH) 2 Precursor

[0134] Weigh 1 g of the Ni containing Zr element in Comparative Example 5 0.96 Co 0.02 Mn 0.02 (OH) 2 Precursor and mix it with 0.4851 g of LiOH·H 2Mix with O, heat to 400 °C at a heating rate of 3 °C / min in an oxygen atmosphere and hold for 5 h, then heat to 730 °C at a heating rate of 3 °C / min and hold for 15 h, and cool to room temperature in the furnace to obtain Zr-doped LiNi 0.96 Co 0.02 Mn 0.02 O 2 cathode material, and then perform electrochemical performance tests according to the conditions of Example 2.

[0135] Comparative Example 6

[0136] This comparative example provides a preparation method of a single-element doped high-nickel precursor and cathode material, which is prepared according to the following steps:

[0137] Synthesize Ni 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor. During the slotting reaction, adjust the rotation speed of the reaction kettle to 430 r / min, adjust the pH to 13.0, and introduce 1 wt% aluminum nitrate until the reaction ends, and finally prepare Ni containing Mo element 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor.

[0138] Weigh 1 g of the Ni 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor containing Mo element in Comparative Example 6 and mix it with 0.4851 g of LiOH·H 2 O. Heat to 400 °C at a heating rate of 3 °C / min in an oxygen atmosphere and hold for 5 h, then heat to 730 °C at a heating rate of 3 °C / min and hold for 15 h, and cool to room temperature in the furnace to obtain Mo-doped LiNi 0.96 Co 0.02 Mn 0.02 O 2 cathode material, and then perform electrochemical performance tests according to the conditions of Example 2.

[0139] Comparative Example 7

[0140] This comparative example provides a preparation method of a single-element doped high-nickel precursor and cathode material, which is prepared according to the following steps:

[0141] Synthesize Ni 0.96 Co 0.02 Mn 0.02 (OH)2 Precursor. During the grooving reaction, the rotation speed of the reaction kettle was adjusted to 430 r / min, the pH was adjusted to 13.0, and 1 wt% of magnesium sulfate was introduced until the reaction ended, and finally a Ni containing Mg element was prepared. 0.96 Co 0.02 Mn 0.02 (OH) 2 Precursor.

[0142] Weigh 1 g of the Ni containing Mg element in Comparative Example 7 0.96 Co 0.02 Mn 0.02 (OH) 2 precursor and mix it with 0.4851 g of LiOH·H 2 O. Heat it to 400 °C at a heating rate of 3 °C / min in an oxygen atmosphere and hold for 5 h, then heat it to 730 °C at a heating rate of 3 °C / min and hold for 15 h, and cool it to room temperature with the furnace to obtain Mg-doped LiNi 0.96 Co 0.02 Mn 0.02 O 2 cathode material, and then carry out electrochemical performance tests according to the conditions of Example 2.

[0143] Comparative Example 8

[0144] Prepare a confined structure Ni without introducing Mo, Ta, Ce, Al and Ca elements according to the conditions of Example 1 0.90 Co 0.05 Mn 0.05 (OH) 2 precursor, and carry out sintering and testing according to the conditions of Example 3.

[0145] Comparative Example 9

[0146] Prepare a confined structure Ni without introducing W, Ta, Ce, Al and Mg elements according to the conditions of Example 4 0.88 Co 0.06 Mn 0.06 (OH) 2 precursor, sinter it according to the conditions of Example 4, and assemble it into a full cell for testing.

[0147] In the preparation process of the confined structure ternary precursor according to the embodiments of the present invention, a +6-valent element is first introduced during the precursor nucleation stage to induce the formation of crystal nuclei, and then +5-valent, +4-valent, +3-valent, and +2-valent elements are sequentially introduced by changing the reaction conditions during the crystal nucleus growth stage. The introduced +6-valent element can induce the formation of crystal nuclei, making the nucleation process controllable. And the ions introduced in a confined manner during the crystal nucleus growth stage can regulate the internal packing degree of the precursor, relieve the stress caused by the structural contraction during the lithium ion deintercalation and intercalation processes during charge and discharge, and improve the structural stability of the material during the cycling process. Moreover, the decreasing valence confinement of ions can regulate the charge and form a high-entropy material on the surface, which can inhibit the release of oxygen during the cycling of the ultra-high nickel material and improve the stability of the material.

[0148] In the preparation process of the confined structure ternary material according to the embodiments of the present invention, first, the above-mentioned confined structure ternary precursor is mixed with a lithium source and subjected to high-temperature sintering in an oxygen atmosphere to prepare an ultra-high nickel cathode material with a radial distribution of entropy-increasing elements and high internal density. The density difference formed by the regulation of the entropy-increasing elements relieves the stress during the lithium ion deintercalation process, so that the high-nickel cathode material has a long cycle life and improved safety. At the same time, the particle cracking caused by stress is reduced, the erosion of the electrolyte on the inside of the spherical particles is avoided, the interfacial side reactions are reduced, and the surface irreversible phase transformation is inhibited to a certain extent.

[0149] It can be understood that those skilled in the art can, under the guidance of the above embodiments, combine various implementation manners in the above various embodiments to obtain technical solutions of various implementation manners.

[0150] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a confined structure ternary precursor, characterized in that: The following steps are involved: The ternary precursor was synthesized by coprecipitation method. In the nucleation stage of the slotting reaction, a +6 valence element was introduced under the first reaction condition to obtain a uniform crystal nucleus. After the crystal nucleus is formed, the reaction conditions are changed to the second reaction conditions, and the +5 valent element is introduced while the +6 valent element is introduced; Changing the reaction conditions to the third reaction conditions, while maintaining the introduction of +6-valent and +5-valent elements, the +4-valent element is introduced; Changing the reaction conditions to the fourth reaction conditions, while maintaining the introduction of +6-valent, +5-valent, and +4-valent elements, the +3-valent element is introduced; Changing the reaction conditions to the fifth reaction conditions, while maintaining the introduction of +6-valent, +5-valent, +4-valent, and +3-valent elements, the +2-valent element is introduced to obtain a confined structure ternary precursor; The +6 valent element is at least one of W, Mo or Cr; the +5 valent element is at least one of V, Nb or Ta; the +4 valent element is at least one of Ti, Zr or Ce; the +3 valent element is at least one of La, Al, Sc or Y; the +2 valent element is at least one of Mg, Cu or Ca; The +6-valent element, +5-valent element, +4-valent element, +3-valent element and +2-valent element are introduced by introducing one or more of nitrates, sulfates, acetates, chlorides, phosphates or carbonates of the corresponding elements; The chemical formula of the ternary precursor is Ni x Co y Mn z (OH)2, where 0.88≤x≤0.98, 0.01≤y≤0.11, 0.01≤z≤0.11, x+y+z=1.

2. The method for preparing a confined structure ternary precursor according to claim 1, characterized in that: The confined structure ternary precursor changes the reaction conditions from the core to the surface layer, introducing +6-valent, +5-valent, +4-valent, +3-valent and +2-valent elements, and the ion valence of the elements also decreases in a confined manner, forming an increase of confined ions from one to five from the core to the surface layer; The proportions of the +6-valent element, the +5-valent element, the +4-valent element, the +3-valent element and the +2-valent element are each controlled within a range of 10-30%.

3. The method for preparing a confined structure ternary precursor according to claim 1, characterized in that: The first reaction condition is a stirring speed of 200~500 r / min and a pH of 11~13.5; the second reaction condition is a stirring speed of 200~460 r / min and a pH of 11~13.2; the third reaction condition is a stirring speed of 220~430 r / min and a pH of 10.8~13.2; the fourth reaction condition is a stirring speed of 220~400 r / min and a pH of 10.5~13; the fifth reaction condition is a stirring speed of 240~380 r / min and a pH of 10~13.

4. The method for preparing a confined structure ternary precursor according to claim 1, characterized in that: During the preparation of the confined structure ternary precursor, the particle size of the precursor increases by 0.5-5 μm under each reaction condition.

5. A confined structure ternary precursor obtained by the preparation method according to any one of claims 1 to 4.

6. A method for preparing a confined structure ternary material, characterized in that: The following steps are involved: The confined structure ternary precursor obtained by the preparation method according to any one of claims 1 to 4 is mixed with an excess of 1 to 10% of a lithium source, and subjected to high temperature sintering to obtain a confined structure ternary material; The temperature and time of the high temperature sintering are: sintering at 400-600°C for 2-6 hours, and sintering at 600-900°C for 10-20 hours, wherein the heating rate is 1-5°C / min; The lithium source is one or more of lithium hydroxide, lithium fluoride, lithium sulfide, lithium carbonate, lithium phosphate or lithium dihydrogen phosphate.

7. A confined structure ternary material obtained by the preparation method described in claim 6.

8. Use of the confined structure ternary precursor according to claim 5 or the confined structure ternary material according to claim 7, characterized in that: The confined structure ternary precursor or the confined structure ternary material is applied in lithium ion batteries or supercapacitors.

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