WO2021248860A1 - 一种无钴单晶复合材料、其制备方法和用途 - Google Patents

一种无钴单晶复合材料、其制备方法和用途 Download PDF

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WO2021248860A1
WO2021248860A1 PCT/CN2020/135524 CN2020135524W WO2021248860A1 WO 2021248860 A1 WO2021248860 A1 WO 2021248860A1 CN 2020135524 W CN2020135524 W CN 2020135524W WO 2021248860 A1 WO2021248860 A1 WO 2021248860A1
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cobalt
single crystal
free single
composite material
lithium salt
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PCT/CN2020/135524
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English (en)
French (fr)
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王鹏飞
江卫军
乔齐齐
孙明珠
许鑫培
施泽涛
马加力
陈思贤
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蜂巢能源科技有限公司
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Priority to EP20940021.7A priority Critical patent/EP4024518A4/en
Priority to US17/785,847 priority patent/US20230036288A1/en
Priority to KR1020227018456A priority patent/KR20220093341A/ko
Publication of WO2021248860A1 publication Critical patent/WO2021248860A1/zh

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    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
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    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
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Definitions

  • the present disclosure relates to the field of battery technology, for example, to a cobalt-free single crystal composite material, a preparation method and application thereof.
  • ternary cathode materials have caused people's research and development boom due to their high energy density, high cycle, high safety and other advantages.
  • large-scale commercialized ternary materials such as NCM523 and NCM622 can meet the needs of power vehicles to a certain extent, and their cruising range and safety performance need to be improved.
  • Single crystal materials are directly composed of independent crystals of 2 to 5 microns, which have the characteristics of higher crystallinity and more stable layered structure.
  • the capacity and circulation of the simple matrix material are low, and the main material is lithium without cobalt single crystal materials.
  • Poor ionic conductivity results in that the ionic conductivity restricts the insertion and migration speed of lithium ions during the charging and discharging process of the battery, which is not conducive to the development of the material capacity, and the internal resistance of the battery increases as the cycle progresses, and the battery is easy to generate heat, which is very big The use of safety hazards.
  • CN109962223A discloses a lithium ion battery containing a cobalt-free Ni-Mn solid solution nickel-based positive electrode material.
  • the positive electrode active material is a modified BN-coated cobalt-free Ni-Mn solid solution nickel-based positive electrode material, and its structural formula is: LiNi x Mn 1-x O 2 ⁇ aBN, where 0.5 ⁇ x ⁇ 1, 0 ⁇ a ⁇ 0.06, and modified BN is the coating layer on the surface of LiNi x Mn 1-x O 2 material.
  • the lithium ion conductivity of the positive electrode material is poor and the cost is relatively high.
  • CN103943844B discloses a cobalt-free lithium-rich manganese-based positive electrode material and a preparation method and application thereof.
  • the chemical formula of the positive electrode material is Li 1+x Ni y Mn 0.8-y O 2 (0 ⁇ x ⁇ 1/3, 0 ⁇ y ⁇ 0.8).
  • the preparation process of the positive electrode material the precursor is prepared in ethanol or deionized water solvent by the sol-gel method, after low-temperature pre-sintering, ball milling, and then high-temperature solid-phase sintering to obtain the prepared positive electrode material.
  • the lithium ion conductivity of the cathode material obtained by the method is poor.
  • the present disclosure provides a cobalt-free single crystal composite material, a preparation method and application thereof.
  • An embodiment of the present disclosure provides a cobalt-free single crystal composite material.
  • the cobalt-free single crystal material has a core-shell structure, the core layer is a cobalt-free single crystal material, and the material composition of the shell layer includes TiNb 2 O 7 and conductive Lithium salt.
  • TiNb 2 O 7 and conductive lithium salt are selected as the material of the shell layer to coat the cobalt-free single crystal material, which facilitates the insertion and removal of lithium ions inside the material during the charge and discharge process, and improves
  • the lithium ion conductivity of the cobalt-free single crystal material increases the capacity and first effect of the material; the shell layer helps reduce the contact area between the material and the electrolyte, slows down the occurrence of side reactions between the material and the electrolyte, and improves the material’s performance. Cycle performance.
  • TiNb 2 O 7 and conductive lithium salt interact with each other to achieve the most excellent technical effect.
  • the reaction between the shell layer and the electrolyte will destroy the TiNb 2 O 7 as the cycle progresses.
  • Material structure; the conductive lithium salt in the shell can inhibit side reactions with the electrolyte and enhance the stability of the coating material.
  • the shell is only coated with conductive lithium salt, it cannot achieve co-coating and improve the lithium ion conductivity. Rate effect.
  • the chemical formula of the cobalt-free single crystal material is Li m Ni x Mn y MnO 2 , and the 0.4 ⁇ x ⁇ 0.95, such as 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85 or 0.9, etc.; 0.05 ⁇ y ⁇ 0.6, such as 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5 or 0.55, etc.; m is 1.05-1.5, such as 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4 or 1.45 etc.
  • the conductive lithium salt includes at least one of LiH 2 PO 4 , CaF 2 , TiN, TiC, LiAlO 2 and BiO-YO.
  • the conductive lithium salt is LiH 2 PO 4 .
  • the molar ratio of TiNb 2 O 7 to the conductive lithium salt in the shell layer is (0.1-10):1, for example, 0.5:1, 1:1, 1.5:1, 2:1, 2.5 :1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1 , 9:1 or 9.5:1, etc.
  • the molar ratio of the TiNb 2 O 7 to the conductive lithium salt is (0.1-10):1, the content of TiNb 2 O 7 is too much, and the content of the conductive lithium salt is too small, which increases The cost of the composite material is reduced, and the shell structure is easily damaged during the cycle; the content of conductive lithium salt is too much, the content of TiNb 2 O 7 is too little, and the lithium ion conductivity of the composite material is poor. Therefore, only within the ratio range provided by an embodiment of the present disclosure can a better synergy effect be exerted and the optimal technical effect can be achieved.
  • the shell layer accounts for 0.1-0.5wt%, for example, 0.15wt%, 0.2wt%, 0.25wt%, 0.3wt%, 0.35wt%, 0.4wt% % Or 0.45wt% etc.
  • the core layer accounts for 99.5 to 99.9% by weight, for example, 99.55% by weight, 99.6% by weight, 99.65% by weight, 99.7% by weight, 99.75% by weight, and 99.8% by weight. % Or 99.85% by weight, etc.
  • the particle size D50 of the cobalt-free single crystal composite material is 1-5 ⁇ m, for example, 1.5 ⁇ m, 2 ⁇ m, 2.5 ⁇ m, 3 ⁇ m, 3.5 ⁇ m, 4 ⁇ m, 4.5 ⁇ m, or the like.
  • the non-single crystalline cobalt composite material specific surface area of 0.3 ⁇ 1.5m 2 / g, e.g. 0.4m 2 /g,0.5m 2 /g,0.6m 2 /g,0.7m 2 / g , 0.8m 2 /g,0.9m 2 /g,1.0m 2 /g,1.1m 2 /g,1.2m 2 /g,1.3m 2 / g or 1.4m 2 / g and the like.
  • the surface pH of the cobalt-free single crystal composite material is less than or equal to 11.8, such as 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, or 11.5, etc.; total alkali is less than or equal to 3500 ppm, such as 1000 ppm, 1500 ppm, 2000ppm, 2500ppm or 3000ppm etc.
  • a method for preparing the cobalt-free single crystal composite material includes:
  • the cobalt-free single crystal material, TiNb 2 O 7 and conductive lithium salt are mixed and sintered to obtain a cobalt-free single crystal composite material.
  • the method for preparing the cobalt-free single crystal material includes: mixing a lithium salt with a cobalt-free single crystal material precursor, and calcining to obtain a cobalt-free single crystal material.
  • the chemical formula of the cobalt-free single crystal material precursor is Ni a Mn b (OH) 2 , and the 0.4 ⁇ a ⁇ 0.95, such as 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, or 0.9, etc.; 0.05 ⁇ b ⁇ 0.6, such as 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5 or 0.55, etc.
  • the lithium salt includes lithium hydroxide and/or lithium carbonate.
  • the ratio of the molar amount of lithium in the lithium salt to the molar amount of the total metal elements in the cobalt-free single crystal material precursor is 1.05-1.5, such as 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4 or 1.45 etc.
  • the mixing of the lithium salt and the precursor of the cobalt-free single crystal material is stirring mixing.
  • the rotational speed of the stirring and mixing is 1500-2500 rpm, such as 1600 rpm, 1700 rpm, 1800 rpm, 1900 rpm, 2000 rpm, 2100 rpm, 2200 rpm, 2300 rpm, or 2400 rpm.
  • the stirring and mixing time is 5-15 min, for example, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, or 14 min.
  • the calcination is performed in an oxygen atmosphere.
  • the concentration of oxygen in the oxygen atmosphere is ⁇ 99.99%.
  • the flow rate of oxygen in the oxygen atmosphere is 5-10L/min, such as 5.5L/min, 6L/min, 6.5L/min, 7L/min, 7.5L/min, 8L/min, 8.5L/min. min, 9L/min or 9.5L/min, etc.
  • the calcination temperature is 850-1000°C, such as 880°C, 900°C, 920°C, 940°C, 950°C, 960°C, or 980°C.
  • the heating rate of the calcination is 3 to 5°C/min, for example, 3.2°C/min, 3.5°C/min, 3.8°C/min, 4°C/min, 4.2°C/min, 4.5°C/min Or 4.8°C/min, etc.
  • the calcination time is 8-20h, such as 10h, 12h, 14h, 15h, 16h or 18h.
  • the process of cooling, crushing and sieving is further included.
  • the screen to be sieved is 300-400 mesh, such as 300 mesh, 310 mesh, 320 mesh, 330 mesh, 340 mesh, 350 mesh, 360 mesh, 370 mesh, 380 mesh, 390 mesh or 400 mesh. Wait.
  • the weight ratio of the total mass of the TiNb 2 O 7 and the conductive lithium salt to the cobalt-free single crystal material is 1000-3000pmm, such as 1200pmm, 1500pmm, 1600pmm, 1800pmm, 2000pmm, 2200pmm, 2500pmm or 2800pmm, etc. .
  • the weight ratio of the total mass of TiNb 2 O 7 and the conductive lithium salt to the cobalt-free single crystal material is 1000-3000 pmm, and the total mass of TiNb 2 O 7 and the conductive lithium salt is too much, This leads to an increase in the thickness of the coating layer, which is not conducive to the performance of the capacity; the total mass of TiNb 2 O 7 and the conductive lithium salt is too small, which has little effect on the stability of the material.
  • the molar ratio of the TiNb 2 O 7 to the conductive lithium salt is (0.1-10):1, for example 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3 :1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1 Or 9.5:1 etc.
  • the process of mixing the cobalt-free single crystal material, TiNb 2 O 7 and the conductive lithium salt includes: mixing TiNb 2 O 7 and the conductive lithium salt in deionized water, drying, and then mixing with the non-cobalt Cobalt single crystal materials are mixed.
  • TiNb 2 O 7 and conductive lithium salt are first mixed and dissolved in deionized water, and dried, so that the conductive lithium salt and TiNb 2 O 7 material can be uniformly dispersed, and then they are mixed in the cobalt-free single crystal.
  • the material mixing is beneficial to the uniform dispersion of the conductive lithium salt and TiNb 2 O 7 material on the surface of the cobalt-free single crystal material, which in turn is beneficial to improve the electrochemical performance of the product.
  • the mixing is performed in a hand blender.
  • the mixing time is 10-20 minutes, such as 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, or 19 min.
  • the sintering is performed in an oxygen atmosphere.
  • the concentration of oxygen in the oxygen atmosphere is ⁇ 99.99%.
  • the flow rate of oxygen in the oxygen atmosphere is 5-10L/min, such as 5.5L/min, 6L/min, 6.5L/min, 7L/min, 7.5L/min, 8L/min, 8.5L/min. min, 9L/min or 9.5L/min, etc.
  • the sintering temperature is 300-700°C, such as 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, or 650°C.
  • the sintering temperature is 300-700°C. If the temperature is too low, the coating is not strong, and it is easy to fall off in the later cycle; if the temperature is too high, the coating material decomposes and the coating cannot be lifted. Cover effect.
  • the heating rate of the sintering is 3 to 5°C/min, such as 3.2°C/min, 3.5°C/min, 3.8°C/min, 4°C/min, 4.2°C/min, 4.5°C/min Or 4.8°C/min, etc.
  • the sintering time is 6-12h, such as 8h, 10h, 12h, 14h, 15h, 16h or 18h.
  • the process of cooling, crushing and sieving is further included.
  • the method includes the following steps:
  • the lithium salt and the cobalt-free single crystal material precursor are stirred and mixed at a rotating speed of 1500-2500 rpm for 5-15 minutes, and the molar amount of lithium in the lithium salt is compared with the molar amount of the total metal elements in the cobalt-free single crystal material precursor.
  • the ratio is 1.05 ⁇ 1.5.
  • the calcination is carried out at a temperature of 850 ⁇ 1000°C for 8 ⁇ 20h in an oxygen atmosphere with a flow rate of 5 ⁇ 10L/min.
  • the heating rate of the calcination is 3 ⁇ 5°C/min, cooling and crushing, Go through a 300-400 mesh sieve to obtain a cobalt-free single crystal material;
  • a positive pole piece is provided.
  • the positive pole piece includes the cobalt-free single crystal composite material according to an embodiment of the present disclosure.
  • a lithium ion battery is provided, and the lithium ion battery includes the positive pole piece described in an embodiment of the present disclosure.
  • Figures 1 to 2 are SEM images of a cobalt-free single crystal composite prepared by an embodiment of the present disclosure
  • 3 to 4 are SEM images of the cobalt-free single crystal material prepared in Comparative Example 1 of the present disclosure.
  • a preparation method of cobalt-free single crystal composite material includes the following steps:
  • Figures 1 to 2 are SEM images of the cobalt-free single crystal composite material provided in this embodiment. It can be seen from the figure that the single crystal material synthesized in this embodiment has a better morphology, uniform particle distribution, and a particle size range of 1 ⁇ 5 ⁇ m.
  • Example 1 The difference from Example 1 is that the weight ratio of the total mass of TiNb 2 O 7 and LiH 2 PO 4 to the cobalt-free single crystal material in step (2) is 2000 pmm.
  • Example 1 The difference from Example 1 is that the weight ratio of the total mass of TiNb 2 O 7 and LiH 2 PO 4 to the cobalt-free single crystal material in step (2) is 3000 pmm.
  • Example 1 The difference from Example 1 is that the weight ratio of the total mass of TiNb 2 O 7 and LiH 2 PO 4 to the cobalt-free single crystal material in step (2) is 500 pmm.
  • Example 1 The difference from Example 1 is that the molar ratio of TiNb 2 O 7 and LiH 2 PO 4 in step (2) is 0.1:1.
  • Example 1 The difference from Example 1 is that the molar ratio of TiNb 2 O 7 and LiH 2 PO 4 in step (2) is 0.05:1.
  • Example 1 The difference from Example 1 is that the molar ratio of TiNb 2 O 7 and LiH 2 PO 4 in step (2) is 12:1.
  • a preparation method of cobalt-free single crystal composite material includes the following steps:
  • the cobalt-free single crystal composite material obtained in this example has electrochemical performance similar to that of Example 1.
  • the cobalt-free single crystal material obtained in step (1) in Example 1 was used.
  • Figures 3 to 4 are SEM images of the cobalt-free single crystal material provided in this comparative example. It can be seen from the figure that the particle size is not much different from that in Example 1, indicating that the coating in Example 1 does not affect the material Granularity has an impact.
  • cobalt-free single crystal composite material obtained in each example and comparative example was used as a positive electrode active material to assemble a battery:
  • Electrochemical performance test charge and discharge the obtained battery under 25 ⁇ 2°C environment, charge and discharge voltage is 3 ⁇ 4.4V, test 0.1C first week charge specific capacity and 0.1C first week discharge specific capacity respectively , 1C first week discharge specific capacity, first week efficiency (0.1C) and 50-week cycle capacity retention rate (1C), the test results are shown in Table 1;
  • the lithium ion diffusion coefficient of the uncoated material (Comparative Example 1) is -9 power, and after coating, it is increased by an order of magnitude to the -8 power, indicating that TiNb 2 O 7 and conductive lithium salt coating agent It is beneficial to improve the ionic conductivity of the material, thereby improving the electrochemical performance of the material.
  • Example 1 From the comparison between Example 1 and Example 4, it can be seen that too little coating amount will affect the performance of the material capacity.
  • Example 1 From the comparison between Example 1 and Examples 6-7, it can be seen that the molar ratio is too large or too small, and the obtained products have poor electrochemical performance. Only the molar ratio of TiNb 2 O 7 and conductive lithium salt is (0.1 ⁇ 10) :1 hour, can better exert the synergistic effect of TiNb 2 O 7 and conductive lithium salt, and improve the electrochemical performance of cobalt-free single crystal materials.
  • Example 8 of the present disclosure has electrochemical performance similar to that of Example 1.
  • Example 1 From the comparison between Example 1 and Comparative Example 1, it can be seen that the use of the coating structure of the present disclosure to coat the cobalt-free single crystal material can effectively improve the specific capacity, first week efficiency and cycle performance of the cobalt-free single crystal material.

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Abstract

一种无钴单晶复合材料、其制备方法和用途。所述无钴单晶材料为核壳结构，核层为无钴单晶材料，壳层的材料组成包括TiNb 2O 7和导电锂盐。选择TiNb 2O 7和导电锂盐作为壳层的材料包覆无钴单晶材料，提高了无钴单晶材料锂离子导电性，进而提高了材料的容量和首效。

Description

一种无钴单晶复合材料、其制备方法和用途 技术领域
本公开涉及电池技术领域，例如涉及一种无钴单晶复合材料、其制备方法和用途。
背景技术
随着新能源市场的发展，三元正极材料由于其高能量密度、高循环、高安全性等优点引起了人们的研发热潮。在当前动力市场上，大规模商业化的如NCM523、NCM622等三元材料，一定程度上满足动力汽车的需求，其续航里程、安全性能等还有待提高。
NCM中钴元素价格的波动制约了电池的成本控制，且钴金属价格昂贵，易对环境造成污染，而多晶NCM材料多是由200～300纳米的一次颗粒团聚而成的二次颗粒，增大了与电解液的接触面积，在循环过程中材料内部易产生微观裂纹且随着镍含量升高而增加，进而导致更多的电解液渗入颗粒内部，引发更多副反应，破坏材料结构。
单晶材料则直接由2～5微米的独立晶体组成，具有更高结晶度、更加稳定的层状结构等特征，但是单纯的基体材料容量和循环偏低，主要是无钴单晶材料的锂离子导电性差导致，离子导电性制约了电池在充放电过程中锂离子的嵌入迁出速度，不利于材料容量的发挥，且随着循环的进行增加电池内阻，电池易于产热，有很大的使用安全隐患。
CN109962223A公开了一种包含无钴Ni-Mn固溶镍基正极材料的锂离子电池，所述正极活性材料为改性BN包覆无钴Ni-Mn固溶镍基正极材料，其结构式为：LiNi xMn 1-xO 2·aBN，其中0.5≤x<1，0<a≤0.06，改性BN为LiNi xMn 1-xO 2材料表面的包覆层。但是，所述正极材料锂离子导电性较差，且成本较高。
CN103943844B公开了一种无钴富锂锰基正极材料及其制备方法和应用，所述正极材料化学式为Li 1+xNi yMn 0.8-yO 2(0<x<1/3，0<y<0.8)。正极材料的制备过程：采用溶胶-凝胶法在乙醇或去离子水溶剂中制备前驱体，经低温预烧、球磨后，再经高温固相烧结得到所制备的正极材料。但是，所述方法得到的正极材料锂离子导电性较差。
因此，本领域需要开发一种新型无钴单晶材料，所述无钴单晶材料具有优异的锂离子导电性，且成本较低，制备方法简单，可工业化生产。
公开内容
本公开提供一种无钴单晶复合材料、其制备方法和用途。
本公开在一实施例中提供一种无钴单晶复合材料，所述无钴单晶材料为核壳结构，核层为无钴单晶材料，壳层的材料组成包括TiNb 2O 7和导电锂盐。
在本公开提供的一实施例中，选择TiNb 2O 7和导电锂盐作为壳层的材料包覆无钴单晶材料，有利于充放电过程中锂离子在材料内部的嵌入迁出，提高了无钴单晶材料锂离子导电性，进而提高了材料的容量和首效；壳层有利于减小材料与电解液的接触面积，减缓了材料与电解液副反应的发生，从而提高了材料的循环性能。TiNb 2O 7和导电锂盐相互配合起作用，可以达到最优异的技术效果，若壳层的材料只存在TiNb 2O 7，随着循环的进行壳层与电解液反应会破坏TiNb 2O 7材料结构；导电锂盐在壳层中可以起到抑制与电解液副反应，增强包覆材料稳定性的作用，而壳层只采用导电锂盐包覆则达不到共包覆提高锂离子电导率的效果。
在一实施例中，所述无钴单晶材料的化学式为Li mNi xMn yMnO 2，所述0.4≤x≤0.95，例如0.45、0.5、0.55、0.6、0.65、0.7、0.75、0.8、0.85或0.9等；0.05≤y≤0.6，例如0.1、0.15、0.2、0.25、0.3、0.35、0.4、0.45、0.5或0.55等；m为1.05～1.5，例如1.1、1.15、1.2、1.25、1.3、1.35、1.4或1.45等。
在一实施例中，所述导电锂盐包括LiH 2PO 4、CaF 2、TiN、TiC、LiAlO 2和BiO-YO中的至少一种。
在一实施例中，所述导电锂盐为LiH 2PO 4。
在一实施例中，所述壳层中，TiNb 2O 7和导电锂盐的摩尔比为(0.1～10):1，例如0.5:1、1:1、1.5:1、2:1、2.5:1、3:1、3.5:1、4:1、4.5:1、5:1、5.5:1、6:1、6.5:1、7:1、7.5:1、8:1、8.5:1、9:1或9.5:1等。
在本公开提供的一实施例中，所述TiNb 2O 7和导电锂盐的摩尔比为(0.1～10):1，TiNb 2O 7的含量过多，导电锂盐的含量过少，提高了复合材料成本，且壳层结构在循环过程中易破坏；导电锂盐的含量过多，TiNb 2O 7的含量过少，复合材料锂离子电导率较差。因此，只有在本公开一实施例提供的比例范围内，才能够发挥更好的协同作用，达到最优的技术效果。
在一实施例中，所述无钴单晶复合材料中，壳层占比为0.1～0.5wt％，例如0.15wt％、0.2wt％、0.25wt％、0.3wt％、0.35wt％、0.4wt％或0.45wt％等。
在一实施例中，所述无钴单晶复合材料中，核层占比为99.5～99.9wt％，例如99.55wt％、99.6wt％、99.65wt％、99.7wt％、99.75wt％、99.8wt％或99.85wt％等。
在一实施例中，所述无钴单晶复合材料的粒度D50为1～5μm，例如1.5μm、2μm、2.5μm、3μm、3.5μm、4μm或4.5μm等。
在一实施例中，所述无钴单晶复合材料的比表面积为0.3～1.5m 2/g，例如0.4m 2/g、0.5m 2/g、0.6m 2/g、0.7m 2/g、0.8m 2/g、0.9m 2/g、1.0m 2/g、1.1m 2/g、1.2m 2/g、1.3m 2/g或1.4m 2/g等。
在一实施例中，所述无钴单晶复合材料的表面pH≤11.8，例如7.5、8、8.5、9、9.5、10、10.5、11或11.5等；全碱≤3500ppm，例如1000ppm、1500ppm、2000ppm、2500ppm或3000ppm等。
本公开在一实施例中提供一种所述无钴单晶复合材料的制备方法，所述方法包括：
将无钴单晶材料、TiNb 2O 7和导电锂盐混合，进行烧结，得到无钴单晶复合材料。
在一实施例中，所述无钴单晶材料的制备方法包括：将锂盐与无钴单晶材料前驱体混合，进行煅烧，得到无钴单晶材料。
在一实施例中，所述无钴单晶材料前驱体的化学式为Ni aMn b(OH) 2，所述0.4≤a≤0.95，例如0.45、0.5、0.55、0.6、0.65、0.7、0.75、0.8、0.85或0.9等；0.05≤b≤0.6，例如0.1、0.15、0.2、0.25、0.3、0.35、0.4、0.45、0.5或0.55等。
在一实施例中，所述锂盐包括氢氧化锂和/或碳酸锂。
在一实施例中，所述锂盐中锂的摩尔量与无钴单晶材料前驱体中总金属元素的摩尔量之比为1.05～1.5，例如1.1、1.15、1.2、1.25、1.3、1.35、1.4或1.45等。
在一实施例中，所述锂盐与无钴单晶材料前驱体的混合为搅拌混合。
在一实施例中，所述搅拌混合的转速为1500～2500rpm，例如1600rpm、1700rpm、1800rpm、1900rpm、2000rpm、2100rpm、2200rpm、2300rpm或2400rpm等。
在一实施例中，所述搅拌混合的时间为5～15min，例如6min、7min、8min、9min、10min、11min、12min、13min或14min等。
在一实施例中，所述煅烧在氧气氛围中进行。
在一实施例中，氧气氛围中氧气的浓度≥99.99％。
在一实施例中，氧气氛围中氧气的流量为5～10L/min，例如5.5L/min、6L/min、6.5L/min、7L/min、7.5L/min、8L/min、8.5L/min、9L/min或9.5L/min等。
在一实施例中，所述煅烧的温度为850～1000℃，例如880℃、900℃、920℃、940℃、950℃、960℃或980℃等。
在一实施例中，所述煅烧的升温速率为3～5℃/min，例如3.2℃/min、3.5℃/min、3.8℃/min、4℃/min、4.2℃/min、4.5℃/min或4.8℃/min等。
在一实施例中，所述煅烧的时间为8～20h，例如10h、12h、14h、15h、16h或18h等。
在一实施例中，所述煅烧之后，还包括冷却、粉碎和过筛的过程。
在一实施例中，过筛的筛网为300～400目，例如300目、310目、320目、330目、340目、350目、360目、370目、380目、390目或400目等。
在一实施例中，所述TiNb 2O 7和导电锂盐的总质量与无钴单晶材料的重量比为1000～3000pmm，例如1200pmm、1500pmm、1600pmm、1800pmm、2000pmm、2200pmm、2500pmm或2800pmm等。
在本公开提供的一实施例中，TiNb 2O 7和导电锂盐的总质量与无钴单晶材料的重量比为1000～3000pmm，TiNb 2O 7和导电锂盐的总质量过多，会导致包覆层厚度增加，不利于容量的发挥；TiNb 2O 7和导电锂盐的总质量过少，对材料的稳定性提升作用较小。
在一实施例中，所述TiNb 2O 7和导电锂盐的摩尔比为(0.1～10):1，例如0.5:1、1:1、1.5:1、2:1、2.5:1、3:1、3.5:1、4:1、4.5:1、5:1、5.5:1、6:1、6.5:1、7:1、7.5:1、8:1、8.5:1、9:1或9.5:1等。
在一实施例中，所述无钴单晶材料、TiNb 2O 7和导电锂盐混合的过程包括：将TiNb 2O 7和导电锂盐混合溶于去离子水，干燥，然后与所述无钴单晶材料混合。
在本公开提供的一实施例中，先将TiNb 2O 7和导电锂盐混合溶于去离子水，干燥，可以使得导电锂盐与TiNb 2O 7材料均匀分散，然后再于无钴单晶材料混合，有利于导电锂盐与TiNb 2O 7材料在无钴单晶材料表面的均匀分散，进而有利于提 升产品的电化学性能。
在一实施例中，所述混合在手持式搅拌机中进行。
在一实施例中，混合的时间为10～20min，例如11min、12min、13min、14min、15min、16min、17min、18min或19min等。
在一实施例中，所述烧结在氧气氛围中进行。
在一实施例中，氧气氛围中氧气的浓度≥99.99％。
在一实施例中，氧气氛围中氧气的流量为5～10L/min，例如5.5L/min、6L/min、6.5L/min、7L/min、7.5L/min、8L/min、8.5L/min、9L/min或9.5L/min等。
在一实施例中，所述烧结的温度为300～700℃，例如350℃、400℃、450℃、500℃、550℃、600℃或650℃等。
在本公开提供的一实施例中，烧结的温度为300～700℃，温度过低，导致包覆不牢固，在后期循环中容易脱落；温度过高，导致包覆材料分解反而起不到包覆效果。
在一实施例中，所述烧结的升温速率为3～5℃/min，例如3.2℃/min、3.5℃/min、3.8℃/min、4℃/min、4.2℃/min、4.5℃/min或4.8℃/min等。
在一实施例中，所述烧结的时间为6～12h，例如8h、10h、12h、14h、15h、16h或18h等。
在一实施例中，所述烧结之后，还包括冷却、粉碎和过筛的过程。
在一实施例中，所述方法包括如下步骤：
(1)将锂盐与无钴单晶材料前驱体进行转速为1500～2500rpm搅拌混合5～15min，所述锂盐中锂的摩尔量与无钴单晶材料前驱体中总金属元素的摩尔量之比为1.05～1.5，在流量为5～10L/min的氧气氛围中进行温度为850～1000℃的煅烧8～20h，所述煅烧的升温速率为3～5℃/min，冷却，粉碎，过300～400目筛，得到无钴单晶材料；
(2)将TiNb 2O 7和LiH 2PO 4以摩尔比为(0.1～10):1混合溶于去离子水，干燥，然后与所述无钴单晶材料在手持式搅拌机中混合10～20min，所述TiNb 2O 7和LiH 2PO 4的总质量与无钴单晶材料的重量比为1000～3000pmm，然后在流量为5～10L/min的氧气氛围中进行温度为300～700℃的烧结6～12h，所述烧结的升温速率为3～5℃/min，冷却，粉碎，过筛，得到无钴单晶复合材料。
本公开在一实施例中提供一种正极极片，所述正极极片包括本公开一实施 例所述的无钴单晶复合材料。
本公开在一实施例中提供一种锂离子电池，所述锂离子电池包括本公开一实施例所述的正极极片。
附图说明
附图用来提供对本公开技术方案的进一步理解，并且构成说明书的一部分，与本申请的实施例一起用于解释本公开的技术方案，并不构成对本公开技术方案的限制。
图1-图2是本公开一个实施例制备的无钴单晶复合材料的SEM图；
图3-图4是本公开对比例1制备的无钴单晶材料的SEM图。
具体实施例
下面结合附图并通过具体实施方式来进一步说明本公开的技术方案。
实施例1
一种无钴单晶复合材料的制备方法包括如下步骤：
(1)将LiOH粉末与无钴单晶材料前驱体Ni 0.75Mn 0.25(OH) 2进行转速为2000rpm搅拌混合10min，LiOH中锂的摩尔量与无钴单晶材料前驱体Ni 0.75Mn 0.25(OH) 2中总金属元素的摩尔量之比为1.1，在流量为8L/min的氧气氛围中进行温度为900℃的煅烧10h，煅烧的升温速率为4℃/min，冷却，粉碎，过300目筛，得到无钴单晶材料；
(2)将TiNb 2O 7和LiH 2PO 4以摩尔比为1:1混合溶于去离子水，干燥，然后与无钴单晶材料在手持式搅拌机中混合15min，TiNb 2O 7和LiH 2PO 4的总质量与无钴单晶材料的重量比为1000pmm，然后在流量为8L/min的氧气氛围中进行温度为500℃的烧结8h，烧结的升温速率为4℃/min，冷却，粉碎，过筛，得到无钴单晶复合材料。
图1-图2是本实施例提供的无钴单晶复合材料的SEM图，从图中可以看出，本实施例合成的单晶材料形貌较好，颗粒分布均匀，粒度范围在1～5μm。
实施例2
与实施例1的区别在于，步骤(2)TiNb 2O 7和LiH 2PO 4的总质量与无钴单晶材料的重量比为2000pmm。
实施例3
与实施例1的区别在于，步骤(2)TiNb 2O 7和LiH 2PO 4的总质量与无钴单晶材料的重量比为3000pmm。
实施例4
与实施例1的区别在于，步骤(2)TiNb 2O 7和LiH 2PO 4的总质量与无钴单晶材料的重量比为500pmm。
实施例5
与实施例1的区别在于，步骤(2)TiNb 2O 7和LiH 2PO 4摩尔比为0.1:1。
实施例6
与实施例1的区别在于，步骤(2)TiNb 2O 7和LiH 2PO 4摩尔比为0.05:1。
实施例7
与实施例1的区别在于，步骤(2)TiNb 2O 7和LiH 2PO 4摩尔比为12:1。
实施例8
一种无钴单晶复合材料的制备方法包括如下步骤：
(1)将LiOH粉末与无钴单晶材料前驱体Ni 0.75Mn 0.25(OH) 2进行转速为2500rpm搅拌混合5min，LiOH中锂的摩尔量与无钴单晶材料前驱体Ni 0.75Mn 0.25(OH) 2中总金属元素的摩尔量之比为1.3，在流量为10L/min的氧气氛围中进行温度为850℃的煅烧20h，煅烧的升温速率为3℃/min，冷却，粉碎，过400目筛，得到无钴单晶材料；
(2)将TiNb 2O 7和LiH 2PO 4以摩尔比为8:1混合溶于去离子水，干燥，然后与无钴单晶材料在手持式搅拌机中混合20min，TiNb 2O 7和LiH 2PO 4的总质量与无钴单晶材料的重量比为1500pmm，然后在流量为10L/min的氧气氛围中进行温度为700℃的烧结6h，烧结的升温速率为5℃/min，冷却，粉碎，过筛，得到无钴单晶复合材料。
本实施例得到的无钴单晶复合材料具有与实施例1相近的电化学性能。
对比例1
采用实施例1中步骤(1)得到的无钴单晶材料。
图3-图4是本对比例提供的无钴单晶材料的SEM图，从图中可以看出，粒度与实施例1中粒度相差不大，说明实施例1中包覆并未对材料的粒度产生影响。
性能测试：
将各实施例和对比例得到的无钴单晶复合材料(对比例1为无钴单晶材料)作为正极活性物质组装成电池：
按照正极活性物质：导电炭黑SP：聚偏氟乙烯PVDF胶液(固含量为6.05％)＝92:4:4制备正极浆料，并涂布于铝箔上，得到正极极片；
然后将负极极片(锂片)、正极极片、电解液(1mol/L的六氟磷酸锂LiPF 6，碳酸乙烯酯EC：碳酸甲乙酯EMC＝1:1)和隔膜组装成电池。
(1)电化学性能测试：将得到的电池在25±2℃环境下进行充放电测试，充放电电压为3～4.4V，分别测试0.1C首周充电比容量、0.1C首周放电比容量、1C首周放电比容量、首周效率(0.1C)和50周循环容量保持率(1C)，测试结果如表1所示；
(2)粉体电阻测试：将实施例1-3和对比例1得到的无钴单晶复合材料(对比例1为无钴单晶材料)每组取三个平行样，每组称取3.5g，然后将无钴单晶复合材料(对比例1为无钴单晶材料)装入模具(用漏斗引流，防止材料挂壁)，晃平；将模具装到设备上，开始测试，等压力分别压到4KN，8KN，12KN，16KN时，稳定压力后，测量电阻率值(取每组平均值)，测试结果如表2所示；
(3)恒电流间歇滴定技术GITT测试：将实施例1-3和对比例1得到的电池进行充放电(每组取三个电池，分别命名为1号、2号和3号)，测试完成后采用公式计算锂离子扩散系数：
Figure PCTCN2020135524-appb-000001
其中m B：活性物质质量(g)，M B：摩尔质量(g/mol)，V M：摩尔体积(cm3/mol)，S：极片面积(cm 2)，△E S＝E 0-E S，△t＝300s，测试结果如表3所示。
表1
Figure PCTCN2020135524-appb-000002
Figure PCTCN2020135524-appb-000003
表2
  4KN(Ω·cm) 8KN(Ω·cm) 12KN(Ω·cm) 16KN(Ω·cm)
实施例1 2.69×10 5 1.31×10 4 8.07×10 4 5.80×10 4
实施例2 3.08×10 5 9.39×10 4 4.04×10 4 2.57×10 3
实施例3 3.16×10 5 1.20×10 4 5.68×10 3 3.33×10 3
对比例1 3.15×10 5 9.01×10 4 4.24×10 4 2.59×10 4
将实施例1、实施例2、实施例3和对比例1中锂离子扩散系数D的数值在表3列出，在表4中列出锂离子扩散系数D计算过程中的参数(表4中P为活性物质的密度)：
表3
Figure PCTCN2020135524-appb-000004
表4
Figure PCTCN2020135524-appb-000005
Figure PCTCN2020135524-appb-000006
从表1可以看出包覆后对材料的容量和循环性能，相对于未包覆材料(对比例1)均有改进，其中2000ppm包覆最优。
从表2可以看出实施例和对比例得到的材料，在不同压力下的电阻率数量级皆发生变化，采用本公开的包覆结构对无钴单晶材料的电子电导有提升作用。
从表3可以看出未包覆材料(对比例1)锂离子扩散系数为-9次方，包覆后提高了一个数量级为-8次方，说明TiNb 2O 7和导电锂盐包覆剂有利于提高材料的离子电导率，从而提高材料的电化学性能。
通过实施例1与实施例4对比可知，包覆量太少会影响材料容量的发挥。
通过实施例1与实施例6-7对比可知，摩尔比过大或过小，得到的产品电化学性能皆较差，只有选取TiNb 2O 7和导电锂盐的摩尔比为(0.1～10):1时，能够更好发挥TiNb 2O 7和导电锂盐的协同作用，提高无钴单晶材料的电化学性能。
本公开实施例8得到的无钴单晶复合材料具有与实施例1相近的电化学性能。
通过实施例1与对比例1对比可知，采用本公开的包覆结构对无钴单晶材料进行包覆，可有效地提升无钴单晶材料的比容量、首周效率和循环性能。

Claims (41)

  1. 一种无钴单晶复合材料，所述无钴单晶材料为核壳结构，核层为无钴单晶材料，壳层的材料组成包括TiNb 2O 7和导电锂盐。
  2. 根据权利要求1所述的无钴单晶复合材料，其中，所述无钴单晶材料的化学式为Li mNi xMn yMnO 2，所述0.4≤x≤0.95，0.05≤y≤0.6，m为1.05～1.5。
  3. 根据权利要求1或2所述的无钴单晶复合材料，其中，所述导电锂盐包括LiH 2PO 4、CaF 2、TiN、TiC、LiAlO 2和BiO-YO中的至少一种。
  4. 根据权利要求3所述的无钴单晶复合材料，其中，所述导电锂盐为LiH 2PO 4。
  5. 根据权利要求1-4任一项所述的无钴单晶复合材料，其中，所述壳层中，TiNb 2O 7和导电锂盐的摩尔比为(0.1～10):1。
  6. 根据权利要求1-5任一项所述的无钴单晶复合材料，其中，所述无钴单晶复合材料中，壳层占比为0.1～0.5wt％。
  7. 根据权利要求1-6任一项所述的无钴单晶复合材料，其中，所述无钴单晶复合材料中，核层占比为99.5～99.9wt％。
  8. 根据权利要求1-7任一项所述的无钴单晶复合材料，其中，所述无钴单晶复合材料的粒度D50为1～5μm。
  9. 根据权利要求1-8任一项所述的无钴单晶复合材料，其中，所述无钴单晶复合材料的比表面积为0.3～1.5m 2/g。
  10. 根据权利要求1-9任一项所述的无钴单晶复合材料，其中，所述无钴单晶复合材料的表面pH≤11.8，全碱≤3500ppm。
  11. 一种根据权利要求1-10任一项所述无钴单晶复合材料的制备方法，所述方法包括：
    将无钴单晶材料、TiNb 2O 7和导电锂盐混合，进行烧结，得到无钴单晶复合材料。
  12. 根据权利要求11所述的方法，其中，所述无钴单晶材料的制备方法包括：将锂盐与无钴单晶材料前驱体混合，进行煅烧，得到无钴单晶材料。
  13. 根据权利要求12所述的方法，其中，所述无钴单晶材料前驱体的化学式为Ni aMn b(OH) 2，所述0.4≤a≤0.95，0.05≤b≤0.6。
  14. 根据权利要求12或13任一项所述的方法，其中，所述锂盐包括氢氧化锂和/或碳酸锂。
  15. 根据权利要求12-14任一项所述的方法，其中，所述锂盐中锂的摩尔量与无钴单晶材料前驱体中总金属元素的摩尔量之比为1.05～1.5。
  16. 根据权利要求12-15任一项所述的方法，其中，所述锂盐与无钴单晶材料前驱体的混合为搅拌混合。
  17. 根据权利要求16所述的方法，其中，所述搅拌混合的转速为1500～2500rpm。
  18. 根据权利要求16或17所述的方法，其中，所述搅拌混合的时间为5～15min。
  19. 根据权利要求12-18任一项所述的方法，其中，所述煅烧在氧气氛围中进行。
  20. 根据权利要求19所述的方法，其中，氧气氛围中氧气的浓度≥99.99％。
  21. 根据权利要求19或20所述的方法，其中，氧气氛围中氧气的流量为5～10L/min。
  22. 根据权利要求12-21任一项所述的方法，其中，所述煅烧的温度为850～1000℃。
  23. 根据权利要求12-22任一项所述的方法，其中，所述煅烧的升温速率为3～5℃/min。
  24. 根据权利要求12-23任一项所述的方法，其中，所述煅烧的时间为8～20h。
  25. 根据权利要求12-24任一项所述的方法，其中，所述煅烧之后，还包括冷却、粉碎和过筛的过程。
  26. 根据权利要求25所述的方法，其中，过筛的筛网为300～400目。
  27. 根据权利要求11-26任一项所述的方法，其中，所述TiNb 2O 7和导电锂盐的总质量与无钴单晶材料的重量比为1000～3000pmm。
  28. 根据权利要求11-27任一项所述的方法，其中，所述TiNb 2O 7和导电锂盐的摩尔比为(0.1～10):1。
  29. 根据权利要求11-28任一项所述的方法，其中，所述无钴单晶材料、TiNb 2O 7和导电锂盐混合的过程包括：将TiNb 2O 7和导电锂盐混合溶于去离子水，干燥，然后与所述无钴单晶材料混合。
  30. 根据权利要求11-29任一项所述的方法，其中，所述混合在手持式搅拌机中进行。
  31. 根据权利要求11-30任一项所述的方法，其中，混合的时间为10～20min。
  32. 根据权利要求11-31任一项所述的方法，其中，所述烧结在氧气氛围中进行。
  33. 根据权利要求32所述的方法，其中，氧气氛围中氧气的浓度≥99.99％。
  34. 根据权利要求32或33所述的方法，其中，氧气氛围中氧气的流量为5～10L/min。
  35. 根据权利要求11-34任一项所述的方法，其中，所述烧结的温度为300～700℃。
  36. 根据权利要求11-35任一项所述的方法，其中，所述烧结的升温速率为3～5℃/min。
  37. 根据权利要求11-36任一项所述的方法，其中，所述烧结的时间为6～12h。
  38. 根据权利要求11-37任一项所述的方法，其中，所述烧结之后，还包括冷却、粉碎和过筛的过程。
  39. 根据权利要求11-38任一项所述的方法，其中，所述方法包括如下步骤：
    (1)将锂盐与无钴单晶材料前驱体进行转速为1500～2500rpm搅拌混合5～15min，所述锂盐中锂的摩尔量与无钴单晶材料前驱体中总金属元素的摩尔量之比为1.05～1.5，在流量为5～10L/min的氧气氛围中进行温度为850～1000℃的煅烧8～20h，所述煅烧的升温速率为3～5℃/min，冷却，粉碎，过300～400目筛，得到无钴单晶材料；
    (2)将TiNb 2O 7和LiH 2PO 4以摩尔比为(0.1～10):1混合溶于去离子水，干燥，然后与所述无钴单晶材料在手持式搅拌机中混合10～20min，所述TiNb 2O 7和LiH 2PO 4的总质量与无钴单晶材料的重量比为1000～3000pmm，然后在流量为5～10L/min的氧气氛围中进行温度为300～700℃的烧结6～12h，所述烧结的升温速率为3～5℃/min，冷却，粉碎，过筛，得到无钴单晶复合材料。
  40. 一种正极极片，所述正极极片包括权利要求1-10任一项所述的无钴单晶复合材料。
  41. 一种锂离子电池，所述锂离子电池包括权利要求40所述的正极极片。
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CN113517424A (zh) * 2021-04-27 2021-10-19 湖南杉杉能源科技股份有限公司 一种高电压锂离子电池无钴正极材料及其制备方法
CN113611834B (zh) * 2021-07-30 2023-01-24 蜂巢能源科技有限公司 一种三层核壳结构的正极材料、制备方法及电池
CN114094070B (zh) * 2021-11-10 2024-03-29 云南中晟新材料有限责任公司 一种铌酸钛包覆硬碳复合材料及其制备方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011238523A (ja) * 2010-05-12 2011-11-24 Toyota Motor Corp 複合正極活物質の製造方法、全固体電池の製造方法および複合正極活物質
CN102496710A (zh) * 2011-12-31 2012-06-13 湖南杉杉户田新材料有限公司 一种镍基多元正极材料及其制备方法
CN103828096A (zh) * 2011-09-30 2014-05-28 旭硝子株式会社 锂离子二次电池用正极活性物质及其制造方法
CN103943844A (zh) 2014-04-04 2014-07-23 西安交通大学 一种无钴富锂锰基正极材料及其制备方法和应用
CN109860588A (zh) * 2019-02-28 2019-06-07 蜂巢能源科技有限公司 锂电池正极材料及其制备方法和应用
CN109962223A (zh) 2019-03-07 2019-07-02 浙江超威创元实业有限公司 一种包含无钴Ni-Mn固溶镍基正极材料的锂离子电池
CN110277554A (zh) * 2019-03-22 2019-09-24 北方奥钛纳米技术有限公司 正极材料和正极片及其制备方法、锂离子电池
CN111682175A (zh) * 2020-06-09 2020-09-18 蜂巢能源科技有限公司 一种无钴单晶复合材料、其制备方法和用途

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5694221B2 (ja) * 2012-03-23 2015-04-01 株式会社東芝 非水電解質電池及び電池パック
CN104037407B (zh) * 2014-05-22 2017-04-05 北大先行科技产业有限公司 一种锂超离子导体包覆的钴酸锂复合材料及其制备方法
US12027661B2 (en) * 2015-06-01 2024-07-02 Forge Nano Inc. Nano-engineered coatings for anode active materials, cathode active materials, and solid-state electrolytes and methods of making batteries containing nano-engineered coatings
CN105244488B (zh) * 2015-11-16 2018-05-08 湖南杉杉能源科技股份有限公司 一种锂离子电池复合包覆正极材料及其制备方法
CN106450273B (zh) * 2016-09-19 2019-03-29 中国电子科技集团公司第十八研究所 一种改善高低温性能的动力ncm523材料的制备方法
CN107546379B (zh) * 2017-08-18 2020-02-28 宁波致良新能源有限公司 磷酸锰铁锂-三元材料复合正极材料及其制备方法
CN108878859A (zh) * 2018-06-07 2018-11-23 中航锂电（洛阳）有限公司 一种镍钴锰酸锂正极材料及其制备方法，锂离子电池
CN111244397A (zh) * 2018-11-28 2020-06-05 天津国安盟固利新材料科技股份有限公司 一种高镍三元正极材料及其制备方法
CN109811412B (zh) * 2018-12-28 2021-06-11 广东邦普循环科技有限公司 一种单晶形貌的层状镍锰酸锂正极材料及其制备方法
CN110854372A (zh) * 2019-11-26 2020-02-28 宁夏百川新材料有限公司 一种锂离子电池正极材料及其制备方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011238523A (ja) * 2010-05-12 2011-11-24 Toyota Motor Corp 複合正極活物質の製造方法、全固体電池の製造方法および複合正極活物質
CN103828096A (zh) * 2011-09-30 2014-05-28 旭硝子株式会社 锂离子二次电池用正极活性物质及其制造方法
CN102496710A (zh) * 2011-12-31 2012-06-13 湖南杉杉户田新材料有限公司 一种镍基多元正极材料及其制备方法
CN103943844A (zh) 2014-04-04 2014-07-23 西安交通大学 一种无钴富锂锰基正极材料及其制备方法和应用
CN109860588A (zh) * 2019-02-28 2019-06-07 蜂巢能源科技有限公司 锂电池正极材料及其制备方法和应用
CN109962223A (zh) 2019-03-07 2019-07-02 浙江超威创元实业有限公司 一种包含无钴Ni-Mn固溶镍基正极材料的锂离子电池
CN110277554A (zh) * 2019-03-22 2019-09-24 北方奥钛纳米技术有限公司 正极材料和正极片及其制备方法、锂离子电池
CN111682175A (zh) * 2020-06-09 2020-09-18 蜂巢能源科技有限公司 一种无钴单晶复合材料、其制备方法和用途

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