Positive electrode material, battery, electric device and preparation method of positive electrode material
The high-valent transition metal doped Li1.2 (Mn0.6Ni0.2Co0.2)1-xTMxO2 positive electrode material was prepared by co-precipitation method, which solved the problems of low capacity and poor circulation performance of the O2-type structure lithium-rich manganese-based positive electrode material, achieved high energy density and excellent discharge capacity, and improved cycle stability and first-time Coulomb efficiency.
Patent Information
- Application Number
- CN202510684060.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-26
- Publication Date
- 2025-08-26
AI Technical Summary
The existing O2-type structure lithium-manganese-based positive electrode materials have problems such as low capacity and poor circulation performance, and are of poor practicality.
The transition metal carbonate precursor was prepared by co-precipitation method, and the sodium-rich transition metal carbonate precursor was obtained through hydrothermal treatment and pre-sintering treatment. Then, it was sintered with the lithium salt to form Li1.2 (Mn0.6Ni0.2Co0.2) 1-xTMxO2 positive electrode material. TM is a high-valent transition metal element, ensuring the high energy density and cycle stability of the battery.
The discharge capacity and cycle life of the positive electrode material are improved, irreversible losses during lithium ion deintercalation are suppressed, the stability of the Li-O-Li structure is enhanced, the transformation of the layered structure into a spinel structure is prevented, and the first Coulomb efficiency and cycle stability are improved.
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Figure CN120545352A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of batteries, and in particular to a positive electrode material, a battery, an electrical device and a method for preparing the positive electrode material. Background Art
[0002] As the use of fossil fuels continues to decline, the use of alternative clean energy sources is increasing. As the most common energy storage method in the 21st century, lithium-ion batteries have become an indispensable part of human society. Consequently, the need to increase the energy density and cycle life of lithium-ion batteries while reducing battery costs is becoming increasingly urgent.
[0003] Lithium-rich manganese-based cathode materials (LMROs) xLi2MnO3(1-x)·LiMO2 (M=Ni, Co or Mn) are considered to be the most promising candidate materials for the next generation of lithium-ion batteries due to their high specific capacity and cost-effectiveness. However, the material still faces major challenges in large-scale commercialization, such as low initial Coulombic efficiency and poor cycling performance. The main reason for these problems is the coupling effect between irreversible oxygen reduction and layered-spinel transformation. In order to solve these problems, researchers proposed the design of O2-type structure, which has greater interlayer electrostatic repulsion than the traditional O3-type structure, inhibits the movement of transition metals in the Li layer, and promotes the reduction of high-potential anions, thereby inhibiting the release of oxygen in traditional lithium-rich electrodes. However, the O2-type structure lithium-rich manganese-based cathode materials in related technologies often have the disadvantages of low capacity utilization and poor cycling performance, and are less practical. Summary of the Invention
[0004] The embodiments of the present invention provide a positive electrode material, a battery, an electrical device, and a method for preparing the positive electrode material, so as to at least solve the problem in the related art that O2-type lithium-rich manganese-based positive electrode materials often have the disadvantages of low capacity utilization and poor cycle performance, and poor practicality.
[0005] The embodiment of the present invention discloses a positive electrode material, the chemical formula of the positive electrode material is Li 1.2 (Mn 0.6 Ni 0.2 Co 0.2 ) 1-x TM x O2, wherein 0≤x<1, the TM is a transition metal element, and the valence state of the transition metal element is greater than positive trivalence.
[0006] Optionally, the transition metal element includes at least one of lanthanum, aluminum, and zirconium.
[0007] A method for preparing the positive electrode material as described above, the method comprising:
[0008] A transition metal carbonate precursor is prepared by coprecipitation using manganese salt, nickel salt, cobalt salt and doped transition metal salt as raw materials;
[0009] hydrothermally treating the transition metal carbonate precursor and the sodium salt to obtain a sodium-rich transition metal carbonate precursor;
[0010] Pre-calcining the sodium-rich transition metal carbonate precursor to obtain a sodium-rich manganese-based material;
[0011] The sodium-rich manganese-based material and lithium salt are sintered to obtain the positive electrode material.
[0012] Optionally, the transition metal carbonate precursor is prepared by a coprecipitation method using manganese salt, nickel salt, cobalt salt and doped transition metal salt as raw materials, comprising:
[0013] dissolving the manganese salt, nickel salt, and cobalt salt in deionized water to obtain a mixed metal salt solution, and dissolving the doped transition metal salt in deionized water to obtain a transition metal salt solution;
[0014] The mixed metal salt solution, the transition metal salt solution and the alkali solution are pumped into a reaction kettle for stirring and aging to obtain the transition metal carbonate precursor.
[0015] Optionally, the step of pumping the mixed metal salt solution, the transition metal salt solution, and the alkali solution into a reactor for stirring and aging to obtain the transition metal carbonate precursor comprises:
[0016] Under the condition that the pH value in the reactor is maintained at 8, the mixed metal salt solution, the transition metal salt solution and the alkali solution are pumped into the reactor for stirring and aging to obtain the transition metal carbonate precursor.
[0017] Optionally, the hydrothermal treatment of the transition metal carbonate precursor and the sodium salt to obtain a sodium-rich transition metal carbonate precursor comprises:
[0018] adding the transition metal carbonate precursor and the sodium salt into a hydrothermal kettle and performing hydrothermal treatment to obtain a hydrothermal treatment product;
[0019] The hydrothermal treatment product is washed and dried in sequence to obtain the sodium-rich transition metal carbonate precursor.
[0020] Optionally, the pre-calcining treatment of the sodium-rich transition metal carbonate precursor to obtain the sodium-rich manganese-based material comprises:
[0021] Pre-calcining the sodium-rich transition metal carbonate precursor in an oxygen atmosphere to obtain a pre-calcined product;
[0022] The pre-calcined product is cooled, ground and sieved in sequence to obtain the sodium-rich manganese-based material.
[0023] Optionally, the sintering of the sodium-rich manganese-based material and the lithium salt to obtain the positive electrode material comprises:
[0024] Mixing the sodium-rich manganese-based material with a lithium salt and performing a sintering treatment to obtain a sintered product;
[0025] The sintered product is ground and sieved to obtain the positive electrode material.
[0026] A battery comprises the positive electrode material as described above.
[0027] An electrical device comprising the positive electrode material as described above, or the battery as described above.
[0028] The embodiments of the present invention include the following advantages:
[0029] In an embodiment of the present invention, a positive electrode material is provided. The chemical formula of the positive electrode material is Li 1.2 (Mn 0.6 Ni 0.2 Co 0.2 ) 1-x TM x O2, where 0≤x<1, TM is a transition metal element, and the valence state of the transition metal element is greater than trivalent. Setting the doping element ratio ensures the battery's high energy density and excellent discharge capacity, improves the doping uniformity of the transition metal elements, and reduces irreversible losses during lithium ion insertion and extraction, thereby increasing the cycle life. In addition, the doping of high-valence (greater than trivalent) transition metal elements helps enhance the stability of the Li-O-Li structure, inhibits crystal structure slip, and prevents the transformation of the layered structure to the spinel structure, thereby improving the cycle stability and first coulombic efficiency of the positive electrode material. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 is a flow chart of the steps of a method for preparing a positive electrode material provided in an embodiment of the present invention;
[0031] Figure 2 is a SEM image of the positive electrode material prepared in Example 1 of the present invention provided in the embodiments of the present invention;
[0032] Figure 3 1 is a graph showing the first charge and discharge curves of button cells assembled based on the positive electrode material of Example 1 and button cells assembled based on the positive electrode materials of Comparative Examples 1 and 2 at a discharge rate of 0.1C provided in the embodiments of the present invention;
[0033] Figure 4 This is a cycle curve diagram of the button battery assembled based on the positive electrode material of Example 1 and the button battery assembled based on the positive electrode materials of Comparative Example 1 and Comparative Example 2 at a discharge rate of 0.1C provided in the embodiments of the present invention. DETAILED DESCRIPTION
[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0035] As the use of fossil fuels continues to decline, the use of alternative clean energy sources is increasing. As the most common energy storage method in the 21st century, lithium-ion batteries have become an indispensable part of human society. Consequently, the need to increase the energy density and cycle life of lithium-ion batteries while reducing battery costs is becoming increasingly urgent.
[0036] Lithium-rich manganese-based cathode materials (LMROs) xLi2MnO3(1-x)·LiMO2 (M=Ni, Co or Mn) are considered to be the most promising candidate materials for the next generation of lithium-ion batteries due to their high specific capacity and cost-effectiveness. However, the material still faces major challenges in large-scale commercialization, such as low initial Coulombic efficiency and poor cycling performance. The main reason for these problems is the coupling effect between irreversible oxygen reduction and layered-spinel transformation. In order to solve these problems, researchers proposed the design of O2-type structure, which has greater interlayer electrostatic repulsion than the traditional O3-type structure, inhibits the movement of transition metals in the Li layer, and promotes the reduction of high-potential anions, thereby inhibiting the release of oxygen in traditional lithium-rich electrodes. However, the O2-type structure lithium-rich manganese-based cathode materials in related technologies often have the disadvantages of low capacity utilization and poor cycling performance, and are less practical.
[0037] In order to solve the above problems, the present invention improves the positive electrode materials in the related art based on the core technical concept of high-valent transition metal doping. The present invention will be described in detail below with reference to the accompanying drawings:
[0038] An embodiment of the present invention provides a positive electrode material, the chemical formula of which is Li 1.2 (Mn 0.6 Ni 0.2 Co 0.2 ) 1-x TM x O2, wherein 0≤x<1, the TM is a transition metal element, and the valence state of the transition metal element is greater than positive trivalence;
[0039] In a specific implementation, the chemical formula of the positive electrode material can be Li 1.2 (Mn 0.6 Ni 0.2 Co0.2 ) 1-x TM x O2, where 0≤x<1, TM is a transition metal element, and the valence of the transition metal element is greater than trivalent. The doping ratio ensures high energy density and excellent discharge capacity of the battery, reduces irreversible losses during lithium ion insertion and extraction, and thus improves cycle life. In addition, the doping of high-valence (greater than trivalent) transition metal elements helps enhance the stability of the Li-O-Li structure, inhibits crystal structure slip, and prevents the transformation of the layered structure to the spinel structure, thereby improving the cycle stability and first coulombic efficiency of the positive electrode material.
[0040] In some embodiments of the present application, the transition metal element includes at least one of lanthanum, aluminum, and zirconium.
[0041] In a specific implementation, the transition metal element may include at least one of lanthanum, aluminum, and zirconium. By selecting at least one high-valent metal among lanthanum, aluminum, and zirconium as a doping element, the structural stability of the positive electrode material can be effectively improved, and the lattice stability of the positive electrode material and the cycle performance of the battery can be improved.
[0042] Reference Figure 1 The present invention also provides a method for preparing the positive electrode material as described above. The method may include the following steps:
[0043] Step 101, using manganese salt, nickel salt, cobalt salt and doped transition metal salt as raw materials, preparing a transition metal carbonate precursor by coprecipitation method;
[0044] Step 102, hydrothermally treating the transition metal carbonate precursor and the sodium salt to obtain a sodium-rich transition metal carbonate precursor;
[0045] Step 103, pre-calcining the sodium-rich transition metal carbonate precursor to obtain a sodium-rich manganese-based material;
[0046] Step 104 : sintering the sodium-rich manganese-based material and the lithium salt to obtain the positive electrode material.
[0047] In a specific implementation, a mixed metal salt solution of manganese salt, nickel salt and cobalt salt and a transition metal salt solution doped with a transition metal salt can be prepared. The ratio of each raw material during preparation can refer to the corresponding ratio in the chemical formula, and then a transition metal carbonate precursor is prepared by a co-precipitation method; then, the transition metal carbonate precursor and the sodium salt can be placed in a hydrothermal kettle and hydrothermally treated at a preset temperature for a predetermined time. After washing the hydrothermal treatment product, a sodium-rich transition metal carbonate precursor can be obtained by spray drying.
[0048] Furthermore, the sodium-rich transition metal carbonate precursor can be pre-sintered and ground and sieved to obtain a sodium-rich manganese-based material. Then, the sodium-rich manganese-based material, lithium salt and additives can be sand-milled and sintered to obtain a lithium-rich manganese-based positive electrode material with O2 configuration multi-ion doping modification.
[0049] In the related art, a single solid-phase molten salt method is generally used to prepare O2-type lithium-rich positive electrode materials. The synthesized materials are usually irregular in morphology and imperfect in lattice, which affects the capacity and cycle performance. However, the present application adopts a solid-liquid integrated method to prepare positive electrode materials, which is conducive to the uniform growth of the precursor and the uniform distribution of elements in the material phase, thereby facilitating the subsequent Na + -Li + By exchanging, an O2-type lithium-rich manganese-based positive electrode material with uniform morphology and high crystallinity was prepared, and its first coulombic efficiency, discharge capacity and cycle performance were significantly improved.
[0050] In some embodiments of the present invention, the transition metal carbonate precursor is prepared by coprecipitation using manganese salt, nickel salt, cobalt salt and doped transition metal salt as raw materials, including:
[0051] dissolving the manganese salt, nickel salt, and cobalt salt in deionized water to obtain a mixed metal salt solution, and dissolving the doped transition metal salt in deionized water to obtain a transition metal salt solution;
[0052] The mixed metal salt solution, the transition metal salt solution and the alkali solution are pumped into a reaction kettle for stirring and aging to obtain the transition metal carbonate precursor.
[0053] In practical applications, manganese salt, nickel salt and cobalt salt can be dissolved in deionized water according to the proportion in the chemical formula to obtain a mixed metal salt solution, and the doped transition metal salt can be dissolved in deionized water to obtain a transition metal salt solution, and then an alkali solution (such as ammonium carbonate alkali solution) can be prepared for use; then the mixed metal salt solution, the transition metal salt solution and the alkali solution can be pumped into a reactor for stirring and aging, and the resulting solution can be filtered, washed and dried to obtain a transition metal carbonate precursor.
[0054] In some embodiments of the present invention, the step of pumping the mixed metal salt solution, the transition metal salt solution, and the alkali solution into a reactor for stirring and aging to obtain the transition metal carbonate precursor comprises:
[0055] Under the condition that the pH value in the reactor is maintained at 8, the mixed metal salt solution, the transition metal salt solution and the alkali solution are pumped into the reactor for stirring and aging to obtain the transition metal carbonate precursor.
[0056] In practical applications, before the reaction, 100 mL of a mixed solution of deionized water and ethylene glycol in a ratio of 1:1 can be injected into the reactor as a base liquid, heated to 55° C. in a water bath, and ammonia water is injected to adjust the pH value of the solution to 8; then the mixed metal salt solution, the transition metal salt solution, and the alkali solution are pumped into the reactor, and the pH value of the entire reactor solution system can be maintained at 8 by adjusting the pumping speed of the mixed metal salt solution, the transition metal salt solution, and the alkali solution, and can be stirred and aged for 12 hours at a stirring speed of 900 rpm, and the resulting solution can be filtered, washed, and dried to obtain a transition metal carbonate precursor.
[0057] In this embodiment, by maintaining a suitable pH value and stirring speed, the uniformity of the transition metal carbonate precursor can be ensured, thereby avoiding inconsistent particle size or uneven distribution of transition metal ions due to uneven reaction, and further improving the uniformity of the material morphology and structure.
[0058] In some embodiments of the present invention, the hydrothermal treatment of the transition metal carbonate precursor and the sodium salt to obtain the sodium-rich transition metal carbonate precursor comprises:
[0059] adding the transition metal carbonate precursor and the sodium salt into a hydrothermal kettle and performing hydrothermal treatment to obtain a hydrothermal treatment product;
[0060] The hydrothermal treatment product is washed and dried in sequence to obtain the sodium-rich transition metal carbonate precursor.
[0061] In practical applications, the transition metal carbonate precursor and sodium carbonate solution can be mixed in a molar ratio of 1:1.2, added to a hydrothermal kettle, and reacted at 200°C for 5 hours to obtain a hydrothermal treatment product. After washing the hydrothermal treatment product, the washed hydrothermal treatment product is pumped into a spray dryer at a speed of 10 mL / min for drying to obtain a sodium-rich transition metal carbonate precursor.
[0062] In this embodiment, the hydrothermal treatment, by providing a certain temperature and pressure environment, can promote the exchange of sodium ions and transition metals, help optimize the crystallinity and morphology of the precursor, and improve the stability of the sodium-rich precursor. The hydrothermal treatment also helps remove impurities, ensures uniform incorporation of sodium ions, and further improves the performance of the positive electrode material.
[0063] In some embodiments of the present invention, the pre-calcining of the sodium-rich transition metal carbonate precursor to obtain the sodium-rich manganese-based material comprises:
[0064] Pre-calcining the sodium-rich transition metal carbonate precursor in an oxygen atmosphere to obtain a pre-calcined product;
[0065] The pre-calcined product is sequentially cooled, ground and sieved to obtain the sodium-rich manganese-based material;
[0066] The pre-calcined product is cooled, ground and sieved in sequence to obtain the sodium-rich manganese-based material.
[0067] In practical applications, the sodium-rich transition metal carbonate precursor obtained in the above steps can be pre-fired in an oxygen atmosphere by heating the temperature from room temperature to 550°C at a rate of 2°C / min and keeping the temperature for 3 hours, and then heating the temperature to 900°C at a rate of 5°C / min and keeping the temperature for 12 hours to obtain a pre-fired product. After the pre-fired product is cooled, it can be ground and sieved to obtain a sodium-rich manganese-based material.
[0068] In this embodiment, pre-calcining in an oxygen atmosphere effectively promotes the exchange of lithium and sodium ions, enhancing the material's electrical conductivity and ensuring the crystallinity and stability of the final product. Controlling the heating rate during pre-calcining ensures the integrity of the crystal structure, preventing lattice slip or incomplete reaction, and improving the quality of the sodium-rich manganese-based material.
[0069] In some embodiments of the present invention, the sintering of the sodium-rich manganese-based material and the lithium salt to obtain the positive electrode material comprises:
[0070] Mixing the sodium-rich manganese-based material with a lithium salt and performing a sintering treatment to obtain a sintered product;
[0071] The sintered product is ground and sieved to obtain the positive electrode material.
[0072] In practical applications, the sodium-rich manganese-based material obtained in the previous step can be mixed with lithium carbonate / lithium oxide / lithium nitrate (80:10:10) in a molar ratio of 1:10, and heated at 300°C for 5 hours to obtain a sintered product, which is then ground and sieved to obtain a positive electrode material.
[0073] In this embodiment, the sintering process can promote the combination of lithium salt and sodium-rich manganese-based material, ensure the structural stability of the final product, help improve the electrical conductivity and stability of the material, and further improve its cycle performance and discharge capacity in practical applications.
[0074] The following is an illustrative example of the technical effects of the present application and the positive electrode material preparation process with reference to specific embodiments and comparative examples:
[0075] Example 1:
[0076] An O2-doped lithium-rich manganese-based cathode material with the chemical formula Li 1.2 (Mn 0.6 Ni 0.2Co 0.2 ) 0.95 La 0.05 O2, preparation steps are as follows:
[0077] (1) Preparation of transition metal salt precursor:
[0078] Nickel sulfate, cobalt sulfate and manganese sulfate were weighed at a molar ratio of Ni:Co:Mn=1:1:3, dissolved in deionized water to prepare a 1 mol / L mixed metal salt solution A; lanthanum chloride was weighed at a ratio of (Ni+Co+Mn):La=19:1 to prepare a 1 mol / L transition metal salt solution B; 2 mol / L ammonium carbonate alkali solution was prepared; before the reaction, 100 mL of a mixed solution of deionized water:ethylene glycol=1:1 was injected into the reactor as a base liquid, heated to 55°C in a water bath, and ammonia water was injected to adjust the pH value of the solution to 8; then the A and B salt solutions and the ammonium carbonate alkali solution were pumped into the reactor, and the pH value of the solution system of each reactor was maintained at 8 by adjusting the pumping speed of the A and B salt solutions and the ammonium carbonate alkali solution, and the stirring speed could be controlled to 900 rpm, stirred and aged for 12 hours, and then the obtained solution was filtered, washed and dried to obtain a lanthanum-doped nickel-cobalt-manganese ternary carbonate precursor.
[0079] (2) The carbonate precursor obtained in the above step (1) and the sodium carbonate solution are mixed in a molar ratio of 1:1.2, and added into a hydrothermal kettle. The mixture is reacted at 200° C. for 5 h to obtain a hydrothermal treatment product. The hydrothermal treatment product is washed and then pumped into a spray dryer at a speed of 10 mL / min for drying to obtain a sodium-rich transition metal carbonate precursor.
[0080] (3) The sodium-rich manganese-based positive electrode material precursor obtained in the above step (1) is pre-sintered in an oxygen atmosphere by heating the temperature from room temperature to 550°C at a rate of 2°C / min and holding the temperature for 3 hours, and then heating the temperature to 900°C at a rate of 5°C / min and holding the temperature for 12 hours to obtain a pre-sintered product. After the pre-sintered product is cooled, it is ground and sieved to obtain a sodium-rich manganese-based material.
[0081] (4) The sodium-rich manganese-based material obtained in the above step (3) was mixed with lithium carbonate / lithium oxide / lithium nitrate (80:10:10) in a molar ratio of 1:10, and heated at 300°C for reaction for 5 hours, and then ground and sieved to obtain an O2-type lanthanum-doped lithium-rich manganese-based positive electrode material.
[0082] (5) Battery assembly: The aforementioned O2-type lanthanum-doped lithium-rich manganese-based positive electrode material, conductive carbon black (Super P) and polyvinylidene fluoride (PVDF) can be weighed separately in a mass ratio of 90:5:5. PVDF can then be dissolved in an appropriate amount of N-methylpyrrolidone (NMP), and then the positive electrode material and Super P are added and centrifuged for 15 minutes. After stirring, the slurry is coated on an aluminum foil that has been cleaned with ethanol. Furthermore, the coated aluminum foil can be placed in a 90°C forced air drying oven to dry for 12 hours. The dried positive electrode sheet is cut into discs using a slicer with a diameter of 1 cm, and then placed in a vacuum drying oven at 100°C for vacuum drying for 12 hours. In a vacuum glove box, a metal lithium sheet is used as the negative electrode, Celgard2400 is used as the separator, and 1.2MLiPF6@EC:EMC=3:7 is used as the electrolyte to assemble a CR2032 button battery.
[0083] The battery assembled in this embodiment has an initial discharge capacity of 292 mAh g at 0.1 C in the voltage range of 2.0 to 4.8 V. -1 The first coulombic efficiency is 81.4%, and the capacity retention rate is 98% after 100 cycles at a charge and discharge rate of 0.1C. Figure 2 As shown, the SEM image of the positive electrode material prepared in Example 1 is shown. Figure 2 It can be seen that the positive electrode material provided by the present invention has uniform morphology, good dispersibility and good crystallinity.
[0084] Example 2:
[0085] An O2-doped modified lithium-rich manganese-based cathode material with the chemical formula Li 1.2 (Mn 0.6 Ni 0.2 Co 0.2 ) 0.92 La 0.08 The preparation method is the same as that of Example 1, except that the molar ratio of (Ni+Co+Mn):La in step (1) is changed to 11.5:1.
[0086] The battery assembled in this embodiment has an initial discharge capacity of 252 mAh g at 0.1 C in the voltage range of 2.0 to 4.8 V. -1 The first coulombic efficiency is 78.2%, and the capacity retention rate is 95% after 100 cycles at a charge and discharge rate of 0.1C.
[0087] Example 3:
[0088] An O2-doped lithium-rich manganese-based cathode material with the chemical formula Li 1.2 (Mn 0.6 Ni 0.2 Co0.2 ) 0.98 La 0.02 O2. The preparation method is the same as that of Example 1, except that the molar ratio of (Ni+Co+Mn):La in step (1) is changed to 49:1.
[0089] The battery assembled in this embodiment has an initial discharge capacity of 245 mAh g at 0.1 C in the voltage range of 2.0 to 4.8 V. -1 The first coulombic efficiency is 75.3%, and the capacity retention rate is 91% after 100 cycles at a charge and discharge rate of 0.1C.
[0090] Example 4:
[0091] An O2-doped lithium-rich manganese-based cathode material with the chemical formula Li 1.2 (Mn 0.6 Ni 0.2 Co 0.2 ) 0.95 Al 0.05 The preparation method is the same as that in Example 1, except that the lanthanum chloride in step (1) is replaced with aluminum chloride.
[0092] The battery assembled in this embodiment has an initial discharge capacity of 263 mAh·g at 0.1C in the voltage range of 2.0 to 4.8 V. -1 The first coulombic efficiency is 79.1%, and the capacity retention rate is 96% after 100 cycles at a charge and discharge rate of 0.1C.
[0093] Example 5:
[0094] An O2-doped lithium-rich manganese-based cathode material with the chemical formula Li 1.2 (Mn 0.6 Ni 0.2 Co 0.2 ) 0.95 Zr 0.05 The preparation method is the same as that of Example 1, except that the lanthanum chloride in step (1) is replaced with zirconium tetrachloride.
[0095] The battery assembled in this embodiment has an initial discharge capacity of 259 mAh g at 0.1C in the voltage range of 2.0 to 4.8 V. -1 The first coulombic efficiency is 79.1%, and the capacity retention rate is 96% after 100 cycles at a charge and discharge rate of 0.1C.
[0096] Comparative Example 1:
[0097] A non-O2 configuration ion-doped lithium-rich manganese-based cathode material with the chemical formula Li 1.2 (Mn 0.6 Ni 0.2Co 0.2 ) 0.95 La 0.05 O2.
[0098] The preparation method is the same as that of Example 1, except that Li2CO3 is added in step (3), and steps (2) and (4) are omitted.
[0099] The battery assembled in this embodiment has an initial discharge capacity of 252 mAh g at 0.1 C in the voltage range of 2.0 to 4.8 V. -1 The first coulombic efficiency is 73.9%, and the capacity retention rate is 93% after 100 cycles at a charge and discharge rate of 0.1C.
[0100] Comparative Example 2:
[0101] A non-O2 configuration ion-doped lithium-rich manganese-based cathode material with the chemical formula Li 1.2 Mn 0.6 Ni 0.2 Co 0.2 O2.
[0102] The preparation method is the same as that of Example 1, except that the lanthanum chloride in step (1) is removed (ie, lanthanum doping is no longer performed), and Li2CO3 is added in step (3), and steps (2) and (4) are omitted.
[0103] The battery assembled in this embodiment has an initial discharge capacity of 203.2 mAh·g at 0.1C in the voltage range of 2.0 to 4.8 V. -1 The first coulombic efficiency is 67.3%, and the capacity retention rate is 88% after 100 cycles at a charge and discharge rate of 0.1C.
[0104] On this basis, if Figure 3 As shown, the first charge and discharge curves of the button-type battery assembled based on the positive electrode material of Example 1 and the button-type battery assembled based on the positive electrode materials of Comparative Example 1 and Comparative Example 2 at a discharge rate of 0.1C are shown. Figure 3 The horizontal axis is the gram capacity (unit is milliampere-hour per gram), and the vertical axis is the voltage (unit is volts); Figure 4 The cycle curves of the button-type battery assembled based on the positive electrode material of Example 1 and the button-type battery assembled based on the positive electrode materials of Comparative Examples 1 and Comparative Examples 2 at a discharge rate of 0.1C are shown. Figure 4 The horizontal axis is the number of cycles, and the vertical axis is the gram capacity (in milliampere-hours per gram).
[0105] It can be seen from the above content that the positive electrode material provided in the embodiment of the present invention has excellent discharge capacity, first coulombic efficiency and good cycle stability compared with the comparative example, and can effectively inhibit the irreversible oxygen reduction and layered-spinel transformation of lithium-rich manganese-based positive electrode materials during lithium insertion and deintercalation. It is suitable for promotion in the field of lithium batteries and has broad development prospects.
[0106] It should be noted that for the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should be aware that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.
[0107] An embodiment of the present application also provides a battery, which includes the positive electrode material as described above.
[0108] An embodiment of the present application further provides an electrical device, which includes the positive electrode material as described above, or the battery as described above.
[0109] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.
[0110] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.
[0111] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the above elements.
[0112] The above is a detailed introduction to a positive electrode material, a battery, an electrical device and a method for preparing a positive electrode material. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.
Claims
1. A positive electrode material, characterized in that The chemical formula of the positive electrode material is Li 1.2 (Mn 0.6 Ni 0.2 Co 0.2 ) 1-x TM x O2, wherein 0≤x<1, the TM is a transition metal element, and the valence state of the transition metal element is greater than positive trivalence.
2. The positive electrode material according to claim 1, characterized in that The transition metal element includes at least one of lanthanum, aluminum, and zirconium.
3. A method for preparing the positive electrode material according to any one of claims 1 to 2, characterized in that: The method comprises: A transition metal carbonate precursor is prepared by coprecipitation using manganese salt, nickel salt, cobalt salt and doped transition metal salt as raw materials; hydrothermally treating the transition metal carbonate precursor and the sodium salt to obtain a sodium-rich transition metal carbonate precursor; Pre-calcining the sodium-rich transition metal carbonate precursor to obtain a sodium-rich manganese-based material; The sodium-rich manganese-based material and lithium salt are sintered to obtain the positive electrode material.
4. The method according to claim 3, characterized in that The method uses manganese salt, nickel salt, cobalt salt and doped transition metal salt as raw materials to prepare a transition metal carbonate precursor by coprecipitation, comprising: dissolving the manganese salt, nickel salt, and cobalt salt in deionized water to obtain a mixed metal salt solution, and dissolving the doped transition metal salt in deionized water to obtain a transition metal salt solution; The mixed metal salt solution, the transition metal salt solution and the alkali solution are pumped into a reaction kettle for stirring and aging to obtain the transition metal carbonate precursor.
5. The method according to claim 4, characterized in that The mixed metal salt solution, the transition metal salt solution and the alkali solution are pumped into a reaction kettle for stirring and aging to obtain the transition metal carbonate precursor, comprising: Under the condition that the pH value in the reactor is maintained at 8, the mixed metal salt solution, the transition metal salt solution and the alkali solution are pumped into the reactor for stirring and aging to obtain the transition metal carbonate precursor.
6. The method according to claim 3, characterized in that The hydrothermal treatment of the transition metal carbonate precursor and the sodium salt to obtain a sodium-rich transition metal carbonate precursor comprises: adding the transition metal carbonate precursor and the sodium salt into a hydrothermal kettle and performing hydrothermal treatment to obtain a hydrothermal treatment product; The hydrothermal treatment product is washed and dried in sequence to obtain the sodium-rich transition metal carbonate precursor.
7. The method according to claim 3, characterized in that The pre-calcining treatment of the sodium-rich transition metal carbonate precursor to obtain the sodium-rich manganese-based material comprises: Pre-calcining the sodium-rich transition metal carbonate precursor in an oxygen atmosphere to obtain a pre-calcined product; The pre-calcined product is cooled, ground and sieved in sequence to obtain the sodium-rich manganese-based material.
8. The method according to claim 3, characterized in that The step of sintering the sodium-rich manganese-based material and the lithium salt to obtain the positive electrode material comprises: Mixing the sodium-rich manganese-based material with a lithium salt and performing a sintering treatment to obtain a sintered product; The sintered product is ground and sieved to obtain the positive electrode material.
9. A battery, characterized in that: The battery comprises the positive electrode material according to any one of claims 1 to 2.
10. An electrical device, characterized in that: The electrical device comprises the positive electrode material according to any one of claims 1 to 2, or the battery according to claim 9.