CN109301207A - A kind of surface layer doping Ce3+And surface layer coats CeO2NCM tertiary cathode material and preparation method thereof - Google Patents
A kind of surface layer doping Ce3+And surface layer coats CeO2NCM tertiary cathode material and preparation method thereof Download PDFInfo
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Abstract
The present invention relates to a kind of surface layers to adulterate Ce3+And surface layer coats CeO2NCM tertiary cathode material and preparation method thereof, belong to field of chemical energy storage battery.The materials chemistry formula is wCeO2‑Li[Ni1‑x‑y‑zMnxCoyCez]O2, wherein 0.8 < 1-x-y-z < 1,0 < x+y+z < 0.2,0.005≤w+z≤0.03；By the way that by cerous nitrate and NCM tertiary cathode material 1~2h of ultrasound in ethanol, then uniformly, 4~6h of calcining, obtains after furnace cooling at 500~750 DEG C for grinding.Ce3+The stratiform frame structure for stabilizing NCM tertiary cathode material, reduces the Li in positive electrode surface layer+/Ni2+Mixing；Surface layer CeO2Cladding stabilize electrolyte/electrode interface structure；Significantly improve the high rate performance and stable circulation performance of NCM tertiary cathode material.
Description
Technical field
The present invention relates to a kind of surface layers to adulterate Ce3+And surface layer coats CeO2NCM tertiary cathode material and preparation method thereof,
Belong to field of chemical energy storage battery.
Background technique
Currently, the fossil energies such as coal, petroleum, natural gas are increasingly depleted, in addition, problem of environmental pollution is increasingly becoming various countries pass
The Important Problems of note.The development that pure electric automobile and oil and gas mix electrical automobile is more and more of interest by people.This just needs lithium secondary
Battery fast development is to meet urgent need of the people for new energy battery practical application.In the family of lithium secondary battery, cobalt
Sour lithium, LiFePO4 and ternary material successively performer key player in the market.Cobalt acid lithium is applied to Miniature portable more
Electronic equipment, and LiFePO4 is since specific discharge capacity is relatively low, just gradually replaced ternary material its in power electric automobile
The effect that aspect plays.NCA (Li [Ni is used after tesla's publication in 20120.85Co0.1Al0.05]O2) tertiary cathode material work
After the electric car Model S of power battery, the tide for studying tertiary cathode material all over the world is constantly increased.China
In development high voltage, the nickelic positive ternary material done one's utmost, to meet the requirement of high-capacity electrode material of new generation.
NCM(Li[NixCoyMn1-x-y]O2, x > 0.5) and tertiary cathode material has higher specific discharge capacity (> 200 mAh/
It g), is most potential positive battery material.But current NCM tertiary cathode material obtains extensive commercial applications not yet,
One of the main reasons for this is exactly that its stable circulation performance and high rate performance are poor.This is because Ni element is in NCM tertiary cathode
Segregation can occur in material synthesis processes and in surface enrichment, and Li+And Ni2+Ionic radius it is close, then filled in electrochemistry
During discharge cycles, it is easy to Li occur+/Ni2+Mixing makes the structure of NCM tertiary cathode material change, thus shadow
Ring the electrochemical stability and electrochemistry cycle performance (Nickel-Rich and Lithium-Rich of NCM tertiary cathode material
Layered Oxide Cathodes:Progress and Perspectives, Arumugam Manthiram, James
C.Knight,Seung-Taek Myung,Seung-Min Oh,and Yang-Kook Su,Adv.Energy
Mater.2016,6,1501010)。
Since under de- lithium state, Ni ion is oxidized easily as Ni4+Ion, and the Ni on NCM tertiary cathode material surface layer4 +It is extremely unstable；Meanwhile high pressure makes electrolyte that oxygenolysis easily occur, decomposition product is deposited on NCM tertiary cathode material table
Face, the acidic materials in electrolyte are likely to further corrode NCM tertiary cathode material surface layer.For these reasons, NCM ternary
Positive electrode surface layer can occur to be changed from layer structure to spinel structure.Therefore stable interfacial structure, it is nickelic for improving
The chemical property of positive electrode is most important.And it is believed that the phase transition process of NCM tertiary cathode material be from surface layer to
What inside was gradually spread, so the stability for reinforcing NCM tertiary cathode material surface layer is particularly significant.It finds after study, Ce4+
Ion has strong oxidizing property, and surface layer can be entered to Li layers of Ni after adulterating into lattice2+Ionic oxide formation is Ni3+Ion makes it
(Ce-doped LiNi is turned again on the position 3b of transition metal layer1/3Co(1/3-x/3)Mn1/3Cex/3O2cathode
Materials for use in lithium ion batteries, Zhang Yingjie, Xia Shubiao, Zhang
Yannan,Dong Peng,Yan Yuxing,Yang Ruiming, Chinese Science Bulletin,2012,57
(32), 4181-4187), that is, reduce Li+/Ni2+Mixing.And CeO2It can be used as a kind of fast-ionic conductor (precipitation method conjunction
At nano Ce O2And its performance, Song Xiaolan, Qiu Guanzhou, Qu Peng, Yang Zhenhua, Wu Xuelan, Wang Haibo, Hunan University's journal are (natural
Scientific version), 2004,31 (6), 13-17), by adjusting calcination temperature, it is made to be coated on positive electrode surface.But simple
Ce3+Doping or CeO2That there are still cyclical stabilities is poor for NCM tertiary cathode material after cladding, and capacity and structure are with electrochemistry mistake
Journey carries out the serious problem that decays.
Summary of the invention
In view of this, the purpose of the present invention is to provide a kind of surface layers to adulterate Ce3+And surface layer coats CeO2NCM ternary
Positive electrode and preparation method thereof, by adulterating Ce3+Into surface layer intracell, stablize the stratiform frame knot in cyclic process
Structure.Adulterating parent ion is Ce4+, Ce4+Surface layer can be entered to Li layers 3a Ni with Strong oxdiative ability2+It is oxidized to Ni3+,
It is returned to the position transition metal layer 3b, this reduces Li+/Ni2+Mixing makes Li+Embedding de- process is more convenient.Together
When Ce4+It is reduced into Ce3+It is present in inside positive transition metal layer, stable framework.And surface layer CeO2Cladding can be every
Exhausted electrolyte and electrode directly contact, and stabilize electrolyte/electrode interface structure, slow down sheet charge transfer electricity in cyclic process
Resistance and the polarized continuous increase in surface layer.
The purpose of the present invention is what is be achieved through the following technical solutions.
A kind of surface layer doping Ce3+And surface layer coats CeO2NCM tertiary cathode material, the materials chemistry formula be wCeO2-
Li[Ni1-x-y-zMnxCoyCez]O2, wherein x>0, y>0, z>0, w>0,0.8<1-x-y-z<1,0<x+y+z<0.2,0.005≤w+
z≤0.03。
A kind of surface layer doping Ce3+And surface layer coats CeO2NCM tertiary cathode material preparation method, the method step
It is as follows:
By cerous nitrate and NCM tertiary cathode material 1~2h of ultrasound in ethanol, then grinding is uniform, at 500~750 DEG C
4~6h of lower calcining, furnace cooling obtain a kind of surface layer doping Ce3+And surface layer coats CeO2NCM tertiary cathode material；
Wherein, the chemical formula of NCM tertiary cathode material is Li [Ni1-x-yMnxCoy]O2, x>0, y>0,0.8<1-x-y<1,0
<x+y<0.2；
The molar ratio of Ce and NCM tertiary cathode material is 0.005~0.03:1 in cerous nitrate.
Preferably, the molar ratio of Ni, Mn, Co are 0.869:0.0921:0.0389 in NCM tertiary cathode material.
Preferably, the molar ratio of cerous nitrate and NCM tertiary cathode material is 0.01:1.
Preferably, calcination temperature is 600 DEG C.
Preferably, calcination time 5h.
A kind of lithium ion secondary battery, the positive electrode of the battery are that Ce is adulterated on a kind of surface layer of the present invention3+And
Surface layer coats CeO2NCM tertiary cathode material.
The utility model has the advantages that
(1) the method for the invention is to mix NCM tertiary cathode material with nitric acid cerium salt, passes through the molten of ethanol solution
Solution, grinding, is evenly distributed on NCM tertiary cathode material particle surface for cerous nitrate, by calcining at different temperature, so that
A part of Ce enters inside lattice surface layer, and another part Ce is with CeO2Form be present in positive electrode surface layer.
(2) combination between Ce-O can be greater than the combination energy between other M-O (M=Ni, Co or Mn), so being entrained in table
The Ce of layer transition metal layer3+Help to stablize lattice structure, especially stable lattice structure under high pressure, alleviates NCM
The tertiary cathode material serious problem of oxygen release under high pressure；Ce3+Support layer-lattice structure can be played into surface layer intracell
The effect of stability；And the original Ce into lattice4+With very strong oxidisability, can will migrate to Li layers of Ni2+
It is oxidized to Ni3+, so that nickel ion is migrated back to transition metal layer again, reduce the mixing of surface structure, effectively increase NCM tri-
First positive electrode surface structure stability, while Ce4+Itself is reduced into Ce3+It is stable in the presence of NCM tertiary cathode material transition
In metal layer, redox reaction Ce occurs4++Ni2+→Ce3++Ni3+；Ce3+Doping enters in the transition metal layer on surface layer,
Occupy Ni2+Position, can be played in electrochemistry cyclic process braced frame, inhibit surface structure phase transformation and inhibit Li+/
Ni2+The effect of mixing.In addition, Ce3+Bigger (the rCe of ionic radius3+=0.102nm), doping enter transition metal layer it
Afterwards, facilitate to widen Li+It is embedded in embedding channel out, helps to improve Li+Transmission rate, can significantly improve NCM tertiary cathode
Chemical property of the material at high voltage high magnification (4.5V, >=1C).
(3) by control synthesis temperature, CeO is coated in NCM tertiary cathode material particle surface2, CeO2Electrolysis can be completely cut off
Liquid/electrode directly contacts, and slows down in electrochemistry cyclic process interfacial charge transfer resistance and surface layer is polarized increases speed, make material
Material shows better thermal stability and cyclical stability.
(4) the raw materials used in the present invention is from a wealth of sources, cheap, and the method operating process is simple, technique and skill
Art is easy to accomplish, can be with large-scale commercial application, while this method can be used for other tertiary cathode materials or rich lithium just
The surface of pole material carries out Ce cladding and doping.
Detailed description of the invention
Fig. 1 is X-ray diffraction (XRD) spectrogram of the final product prepared in embodiment 1-4 and comparative example 1.
Fig. 2 is scanning electron microscope (SEM) picture of the final product prepared in comparative example 1.
Fig. 3 is the SEM picture of the final product prepared in embodiment 1.
Fig. 4 is the SEM picture of the final product prepared in embodiment 2.
Fig. 5 is the SEM picture of the final product prepared in embodiment 3.
Fig. 6 is the SEM picture of the final product prepared in embodiment 4.
Fig. 7 is that figure is swept in face power spectrum (EDS) of the final product prepared in embodiment 3.
Fig. 8 is the Ce3d map in x-ray photoelectron spectroscopy (XPS) test of the final product prepared in embodiment 1-4.
Fig. 9 is that the Raman spectrum (Raman) of final product prepared by embodiment 3 tests map.
Figure 10 is the Ni2p map in embodiment 1-4 with the XPS of the final product prepared in comparative example test.
Figure 11 be the CR2025 button cell that assembles of embodiment 1-4 and comparative example 1 in 2.75V~4.5V voltage range and
Cycle performance curve graph under 0.2C (1C=200mAh/g) multiplying power.
The CR2025 button cell that Figure 12 is assembled by the embodiment 1-4 CR2025 button cell assembled and comparative example 1 according to
It is secondary to recycle the high rate performance figure obtained for 5 weeks respectively under different multiplying.
Figure 13 is cyclic voltammetric of the CR2025 button cell of the assembling of comparative example 1 after 2.75-4.5V is recycled 1 week and 50 weeks
(CV) curve graph.
Figure 14 be example 1 group dress CR2025 button cell 2.75-4.5V recycle 1 week and 50 weeks after CV curve graph.
Figure 15 be embodiment 2 assemble CR2025 button cell 2.75-4.5V recycle 1 week and 50 weeks after CV curve graph.
Figure 16 be embodiment 3 assemble CR2025 button cell 2.75-4.5V recycle 1 week and 50 weeks after CV curve graph.
Figure 17 be embodiment 4 assemble CR2025 button cell 2.75-4.5V recycle 1 week and 50 weeks after CV curve graph.
The CR2025 button cell that Figure 18 is embodiment 1-4 and comparative example 1 assembles recycles 50 under Charging state 4.3V voltage
AC impedance (EIS) test chart after week.
Specific embodiment
To be best understood from the present invention, the invention will be described in further detail combined with specific embodiments below.It should be understood that
, the specific embodiments described herein are merely illustrative of the invention, is not intended to restrict the invention.In addition,
The endpoint of disclosed range and any value are not limited to the accurate range or value herein, these ranges or value should manage
Solution is to include the value close to these ranges or value.For numberical range, between the endpoint value of each range, each range
It can be combined with each other between endpoint value and individual point value, and individually between point value and obtain one or more new numerical value
Range, these numberical ranges should be considered as specific open herein.
In following embodiment:
(1) XRD is tested: X-ray diffractometer, and instrument model is Rigaku Ultima IV-185, Japan；
(2) SEM is tested: scanning electron microscope, instrument model: FEI QUANTA 250, the U.S.；
(3) XPS is tested: scanning x-ray photoelectron spectroscopy (XPS), instrument model are as follows: PHI Quantera II, day
This；
(4) Raman is tested: laser Raman spectroscopy, instrument model: Renishaw RM2000；
(5) EDS is tested: the energy disperse spectroscopy used is the Oxford INCA model of Oxford Instruments (Shanghai) Co., Ltd. production
Gamma ray spectrometer.
(6) assembling of CR2025 button cell: positive electrode that comparative example or embodiment are prepared, acetylene black, poly-
Vinylidene (PVDF) is made slurry according to the mass ratio of 8:1:1 and is coated on aluminium foil, is starched the load of drying with slitter
The aluminium foil of material is cut into sequin that diameter is about 1cm and is used as anode, using metal lithium sheet as cathode, Celgard2300 as diaphragm,
The carbonate solution of 1M is that (wherein, solvent is that the mixing of ethylene carbonate and dimethyl carbonate that volume ratio is 1:1 is molten to electrolyte
Liquid, solute LiPF6), CR2025 button cell is assembled into argon gas glove box；
(7) charge and discharge cycles are tested: using CT2001A Alnd cell tester to the CR2025 button cell assembled
Constant current charge-discharge test is carried out under different current densities, definition 1C current density is 200 mA/g, charging/discharging voltage section
For 2.75V~4.5V, test temperature is 25 DEG C；
(8) high rate performance is tested: respectively being followed under the different current density of 0.1C, 0.2C, 1C, 2C, 5C, 10C, 0.1C respectively
Ring 5 weeks, carry out constant current charge-discharge test, wherein after 2C, 5C, 10C high magnification constant-current charge, then constant-voltage charge 1 hour or
Constant-voltage charge is less than 0.05C to current density；
(9) ac impedance measurement: CHI604c electrochemical workstation, China；Test voltage is 4.5V, and frequency range is
0.01Hz~0.1MHz, the amplitude of sine wave AC voltage disturbing signal are 5m, using to electrode as reference electrode；
(10) cyclic voltammetry: CHI660e electrochemical workstation, China；Test voltage section is the V of 2V~4.8, is swept
Retouch rate 0.1mV/s.
LiNi used in Examples 1 to 70.869Mn0.0921Co0.0389O2It is the method according to comparative example 1
It is prepared.
Comparative example 1
(1) according to the molar ratio of Ni:Mn:Co=0.869:0.0921:0.0389 that manganese sulfate, nickel sulfate and cobaltous sulfate is molten
In deionized water, the sulfate solution of 2mol/L is obtained；
(2) alkaline aqueous solution containing 2mol/L sodium carbonate and 2mol/L ammonium hydroxide is configured；
(3) prepared sulfate solution and alkaline aqueous solution are added continuously to peristaltic pump with blender respectively
And in the reaction kettle of logical nitrogen, by adjusting the addition rate control pH value of sulfate solution or alkaline aqueous solution, keep pH steady
It is set to 11, control reaction temperature is 55 DEG C, and mixing speed 650r/min, sample introduction speed is adjusted to 0.25mL/min；Sample introduction is complete
Obtained sediment is filtered, washs, dries, obtain after keeping ageing 6h in a nitrogen atmosphere by Quan Hou
Ni0.869Mn0.0921Co0.0389(OH)2；
(4) by Ni0.869Mn0.0921Co0.0389(OH)2It is mixed with LiOH powder according to the molar ratio of 1:1, first in mortar
Middle dry grinding 25min adds ethyl alcohol and continues to grind 25min, then the mixture of the two is placed in oxygen atmosphere, first 450
DEG C calcining 6h, then is warming up to 750 DEG C of calcining 12h, furnace cooling obtains NCM tertiary cathode material
(LiNi0.869Mn0.0921Co0.0389O2), it is abbreviated as NCM.
Test results are shown in figure 1 by the XRD of NCM, it can be seen that the position of characteristic peak and LiNiO2 (PDF#09-0063)
It is consistent completely, swarming is obvious between (006)/(012) and (018)/(110), indicates that its layer structure is fine.According to XRD
Rietveld refine is as a result, Ni2+Occupy-place in Li layers is 2.98%.
Test results are shown in figure 2 by the SEM of NCM, it can be seen that NCM material can maintain its spherical morphology, and radius is 12
Microns.
The Ni2p map of the XPS test of NCM is as shown in Figure 10, and Ni is mostly with Ni in NCM material2+Form exists.
It is assembled into CR2025 button cell using NCM as positive electrode, and carries out corresponding electrochemical property test.
The battery assembled recycles 50 weeks charge-discharge performance results such as under 2.75-4.5V, 25 DEG C, 0.2C test condition
Shown in Figure 11, first week charging capacity is 214mAh/g, specific discharge capacity 178.7mAh/g, and first week coulombic efficiency is 83.5%,
Discharge capacity is 163.5mAh/g, capacity retention ratio 91.5% after recycling 50 weeks.
The high rate performance result that the battery assembled recycles 5 weeks respectively under different multiplying is as shown in figure 12,10C/0.1C
=112.7mAhg-1/177.8mAh·g-1=63.4%.
The battery assembled 2.75-4.5V recycle 50 weeks after CV Dependence Results it is as shown in figure 13, circulation 50 weeks it
The redox peaks in this interval range of 2.5V-4.6V afterwards have not all been clearly, to illustrate at this time in material
The ion that portion carries out redox contribution capacity is seldom；Also illustrate that material structure is varied widely, and is aoxidized
The position of reduction has also all been changed.
The electrochemical impedance test result of material is as shown in figure 18 after the circulating battery assembled 50 weeks, it can be seen that resistance
Anti- figure includes a semicircle of high frequency region, is interface resistance, and a semicircle of intermediate frequency zone corresponds to charge transfer resistance, and low frequency
The straight line in area is Warburg resistance.The interface resistance R of NCM811 after recycling 50 weeksf=8.79 Ω, charge transfer resistance Rct=
426.7Ω。
Embodiment 1
By cerous nitrate and NCM according to molar ratio Ce:NCM=0.01:1, it is added to ultrasound 1h in ethyl alcohol, then in mortar
It is uniform with ethyl alcohol mixed grinding, 5h is calcined at 400 DEG C, furnace cooling obtains final product, is denoted as post-Ce-400.
Test results are shown in figure 1 by the XRD of post-Ce-400, it is known that in the present embodiment the main peak of post-Ce-400 with it is right
Peak position is almost the same in ratio, in 20-40 degree interval range, mutually generates without miscellaneous peak, it is meant that does not have CeO2It generates.
According to XRD Rietveld refine as a result, in post-Ce-400 sample, Ni2+Occupy-place atomic percentage in Li layers is
1.92%, show Li+/Ni2+Mixing problem is improved.
Test results are shown in figure 3 by the SEM of post-Ce-400, it can be seen that and material sample can maintain its spherical morphology,
Radius is in 12 microns.
Ce3d profiling results in the XPS test of post-Ce-400 are as shown in Figure 8, it can be seen that post-Ce-400 pairs
The characteristic peak of corresponding Ce is not fairly obvious in the XPS map of the Ce3d answered, it can be seen that has faint peak to correspond to
888.0eV (V0), 885.4eV (V '), 897.8eV (u0), position and 903.5eV (u '), it was demonstrated that have Ce3+It is present in surface layer
Intracell.And do not detect Ce with Ce4+The form of ion is present in positive electrode surface, it was demonstrated that Ce and NCM material exist
CeO will not be generated when calcining at 400 DEG C2, illustrate that this calcination temperature cannot form CeO in NCM positive electrode surface2。
The Ni2p profiling results of the XPS test of post-Ce-400 are as shown in Figure 10, it can be seen that Ni is more in NCM material
With Ni2+Form exists, and in post-Ce-400 material, Ni is more with Ni3+Form exists.And it is observed that
Ni2p1/2The position at peak also obviously to the positional shift of higher combination energy, illustrates that the valent state of Ni increases.This is to a certain degree
On also demonstrate Li in post-Ce-400 material+/Ni2+Mixing is inhibited, i.e., provable Ce3+Doping enters surface layer transition gold
Belong in layer.
In the Raman test of post-Ce-400, CeO can't see2It corresponds in 464cm-1The peak of position exists, and further demonstrate,proves
There is no CeO in bright post-Ce-4002Cladding.
It is assembled into CR2025 button cell using post-Ce-400 as positive electrode, and carries out electrochemical property test.
The battery assembled recycles 50 weeks chemical property results such as under 2.75-4.5V, 25 DEG C, 0.2C test condition
Shown in Figure 11, the first all charging capacitys of NCM material are 214mAh/g, specific discharge capacity 178.7mAh/g, and first week coulombic efficiency is
83.5%, discharge capacity is 163.5mAh/g, capacity retention ratio 91.5% after recycling 50 weeks.Post-Ce-400 material
First week charge specific capacity is 226mAh/g, specific discharge capacity 179.2mAh/g, after first week coulombic efficiency is 79.3%, 50 weeks
Specific discharge capacity be 161mAh/g, capacity retention ratio 89.8%.
The performance test results that the battery assembled recycles 5 weeks respectively under different multiplying are as shown in figure 12, available
The 10C/0.1C=112.7mAhg of NCM material-1/177.8mAh·g-1=63.4%.And the 10C/ of post-Ce-400
0.1C=127.8mAhg-1/179.6mAh·g-1=71.2%.Show that post-Ce-400 material structure is more stable,
The capacity retention ratio recycled under high magnification high voltage slightly improves for ontology.
CV Dependence Results of the battery assembled after 2.75-4.5V is recycled 50 weeks are as shown in figure 14, and compare in Figure 13
CV curve comparison in example after NCM material circulation 50 weeks, it can be seen that Post-Ce-400 sample is after circulation 50 weeks
Redox peaks in this interval range of 2.5V-4.6V be not all clearly, illustrate at this time material internal into
Row redox contributes the ion of capacity seldom, also corresponds to the situation that discharge capacity is relatively low in Figure 11.Also illustrate material
Material structure is varied widely, and is carried out redox position and has also all been changed.
The electrochemical impedance test result of material is as shown in figure 18 after the circulating battery assembled 50 weeks, it can be seen that resistance
Anti- figure includes a semicircle of high frequency region, is interface resistance, and a semicircle of intermediate frequency zone corresponds to charge transfer resistance, and low frequency
The straight line in area is Warburg resistance.The interface resistance R of Post-Ce-400 after recycling 50 weeks can be seen in embodiment 1f=8.57
Ω, charge transfer resistance Rct=415.7 Ω.The interface resistance of Post-Ce-400 material and charge transfer resistance be not relative to changing
Property NCM ternary material there is no improve and inhibit.
It can be concluded that post-Ce-400 material surface has doping Ce from these analysis data3+, but do not have
There is CeO2Generation, electrochemical data the result shows that the material without well improve NCM tertiary cathode material chemical property.
Embodiment 2
By cerous nitrate and NCM according to molar ratio Ce:NCM=0.01:1, it is added to ultrasound 1h in ethyl alcohol, then in mortar
It is uniform with ethyl alcohol mixed grinding, 5h is calcined at 500 DEG C, furnace cooling obtains final product, i.e., Ce is adulterated on a kind of surface layer3+And table
Layer cladding CeO2NCM tertiary cathode material, be denoted as post-Ce-500.
Test results are shown in figure 1 by the XRD of post-Ce-500, peak position in the main peak and comparative example in the present embodiment
It is almost the same, in 20-40 degree interval range, there is miscellaneous peak phase CeO2Peak generates, it is meant that material surface has CeO2It generates.According to
XRD Rietveld refine is as a result, in post-Ce-500 sample, Ni2+Occupy-place atomic percentage in Li layers is 1.71%,
Show Li+/Ni2+Mixing problem is improved.
Test results are shown in figure 4 by the SEM of post-Ce-500, it can be seen that and material sample can maintain its spherical morphology,
Radius is in 12 microns.
The EDS power spectrum of post-Ce-500 the result shows that, Ce is present in the material surface of post-Ce-500.
Ce3d profiling results in the XPS test of post-Ce-500 are as shown in figure 8, post-Ce- as we can see from the figure
The characteristic peak of corresponding Ce is fairly obvious in the XPS map of 500 corresponding Ce3d, be present in 882.1eV, 888.9eV,
Corresponding v, v at 898.1eV, 902.4eV, 907.0eV, 916.2eV ", v " ', U, U ", U " ' peak show Ce4+Presence, also
It is that there are CeO in material surface2.It proves that CeO can be generated when Ce and NCM811 is calcined at 500 DEG C2.The XPS of Ce3d schemes
At 888.0eV (V0) in spectrum, the peak of 885.4eV (V '), 897.8eV (u0), the position and 903.5eV (u ') correspond to Ce3+,
Also fairly obvious, it was demonstrated that have Ce in post-Ce-500 sample particle3+Ion is present in surface layer intracell.Also illustrate 500 DEG C
Calcination temperature can make Ce4+Into in the lattice of high-nickel material surface layer with Ni3+Redox reaction Ce occurs4++Ni3+→ Ce3+
+Ni2+, while CeO can be formed in nickelic particle surface2Protective layer stabilizes electrolyte/electrode interface, it is suppressed that surface layer Li+/Ni2+Mixing, to improve the structural stability of NCM tertiary cathode material.
The Ni2p profiling results of the XPS test of post-Ce-500 are as shown in Figure 10, it can be seen that in the NCM material of comparative example
Ni is mostly with Ni in material2+Form exists, and in post-Ce-500 modified material, Ni is more with Ni3+Form exists.And it can
To observe Ni2p1/2The position at peak also obviously to the positional shift of higher combination energy, illustrates that the valent state of Ni increases.This
Li in post-Ce-500 material is also demonstrated to a certain extent+/Ni2+Mixing is inhibited, and Ce3+Doping enters surface layer mistake
It crosses in metal layer, this all will be helpful to NCM tertiary cathode material and maintains lattice structure to stablize under the conditions of height de- lithium state.
In the Raman test of post-Ce-500, the position of the corresponding combination energy in peak is in 464cm-1Correspond to CeO2, and tie
Conjunction can be in 261cm-1And 560cm-1The peak at place is its second order peak.
It is assembled into CR2025 button cell using post-Ce-500 as positive electrode, and carries out electrochemical property test.
The battery assembled recycles 50 weeks chemical property results such as under 2.75-4.5V, 25 DEG C, 0.2C test condition
Shown in Figure 11, the first all charging capacitys of NCM material are 214mAh/g, specific discharge capacity 178.7mAh/g, and first week coulombic efficiency is
83.5%, discharge capacity is 163.5mAh/g, capacity retention ratio 91.5% after recycling 50 weeks.Post-Ce-500 material
First week charge specific capacity is 229.4mAh/g, specific discharge capacity 190.2mAh/g, and first week coulombic efficiency is 82.9%, 50 weeks it
Specific discharge capacity afterwards is 186.1 mAh/g, capacity retention ratio 97.8%.
The performance test results that the battery assembled recycles 5 weeks respectively under different multiplying are as shown in figure 12, available
The 10C/0.1C=112.7mAhg of NCM material-1/177.8mAh·g-1=63.4%.And the 10C/ of post-Ce-500
0.1C=139.9mAhg-1/189.4mAh·g-1=73.9%.Show that post-Ce-500 material structure is more stable,
The capacity retention ratio recycled under high magnification high voltage has improvement relative to NCM material.
CV Dependence Results of the battery assembled after 2.75-4.5V is recycled 50 weeks are as shown in figure 15, with Figure 13 comparative example
CV curve comparison of the middle NCM material circulation after 50 weeks, it can be seen that NCM material circulation 50 weeks after in 2.5V-4.6V
Redox peaks in this interval range have not all been clearly, to illustrate that NCM material internal carries out redox contribution
The ion of capacity is seldom.And in post-Ce-500 material, redox peaks are still high-visible, it was demonstrated that its stratiform
It is structure-preserved preferable, so that one of the various transition metal ions still can restore tribute in 2.5-4.6V voltage range internal oxidition
Offer capacity.
The electrochemical impedance test result of material is as shown in figure 18 after the circulating battery assembled 50 weeks, and circulation is after 50 weeks
The interface resistance R of Post-Ce-500f=4.11 Ω, charge transfer resistance Rct=382 Ω.It can be seen that Post-Ce-500
Interface resistance and Charge-transfer resistance are obviously reduced compared to NCM material.
It can be concluded that post-Ce-500 material surface is doped with Ce from these analysis data3+And it is coated with
CeO2, the chemical property of the material improves significantly relative to without modified NCM tertiary cathode material.
Embodiment 3
By cerous nitrate and NCM according to molar ratio Ce:NCM=0.01:1, it is added to ultrasound 1h in ethyl alcohol, then in mortar
It is uniform with ethyl alcohol mixed grinding, 5h is calcined at 600 DEG C, furnace cooling obtains final product, i.e., Ce is adulterated on a kind of surface layer3+And table
Layer cladding CeO2NCM tertiary cathode material, be denoted as post-Ce-600.
Test results are shown in figure 1 by the XRD of post-Ce-600, peak position in the main peak and comparative example in the present embodiment
It is almost the same, in 20-40 degree interval range, there is miscellaneous peak phase CeO2Peak generates, it is meant that material surface has CeO2It generates.According to
XRD Rietveld refine is as a result, in post-Ce-400 sample, Ni2+Occupy-place atomic percentage in Li layers is 1.46%,
Its Li+/Ni2+Mixing problem is improved.
Test results are shown in figure 5 by the SEM of post-Ce-600, it can be seen that and material sample can maintain its spherical morphology,
Radius is in 12 microns.
The EDS power spectrum result of post-Ce-600 is as shown in Figure 7, it can be seen that Ce is present in the material of post-Ce-600
In surface layer.
Ce3d profiling results in the XPS test of post-Ce-600 are as shown in figure 8, post-Ce- as we can see from the figure
The characteristic peak of corresponding Ce is fairly obvious in the XPS map of 600 corresponding Ce3d, can by be present in 882.1eV,
Corresponding v, v at 888.9eV, 898.1eV, 902.4eV, 907.0eV, 916.2eV ", v " ', U, U ", U " ' peak correspond to Ce4+
In the presence of, that is, there are CeO in material surface2.It proves to give birth to when Ce and NCM tertiary cathode material is calcined at 600 DEG C
At CeO2.In 888.0eV (V0), 885.4eV (V '), 897.8eV (u0), the position and 903.5eV (u ') in the XPS map of Ce3d
The peak set corresponds to Ce3+, also fairly obvious, it was demonstrated that have Ce in post-Ce-600 sample particle3+Ion is present in surface layer lattice
It is internal.Also illustrate that 600 DEG C of calcination temperature can make Ce4+Into in the lattice of high-nickel material surface layer with Ni3+It is anti-that redox occurs
Answer Ce4++Ni3+→Ce3++Ni2+, while CeO can be formed in nickelic particle surface2Protective layer stabilizes electrolyte/sector electrode
Face, it is suppressed that surface layer Li+/Ni2+Mixing, to improve the structural stability of NCM tertiary cathode material.
The Ni2p profiling results of the XPS test of post-Ce-600 are as shown in Figure 10, it can be seen that in the NCM material of comparative example
Ni is mostly with Ni in material2+Form exists, and in post-Ce-600 material, Ni is more with Ni3+Form exists.And it can be with
Observe Ni2p1/2The position at peak also obviously to the positional shift of higher combination energy, illustrates that the valent state of Ni increases.This is one
Determine to also demonstrate Li in post-Ce-600 material in degree+/Ni2+Mixing is inhibited, and Ce3+Doping enters transition metal
In layer, this all will be helpful to NCM tertiary cathode material and maintains lattice structure to stablize under the conditions of height de- lithium state.
Test results are shown in figure 9 by the Raman of post-Ce-600, and the position of the corresponding combination energy in Raman test peak exists
464cm-1Correspond to CeO2, and combining can be in 261cm-1And 560cm-1The peak at place is its second order peak.
It is assembled into CR2025 button cell using post-Ce-600 as positive electrode, and carries out electrochemical property test.
The battery assembled recycles 50 weeks chemical property results such as under 2.75-4.5V, 25 DEG C, 0.2C test condition
Shown in Figure 11, the first all charging capacitys of NCM material are 214mAh/g, specific discharge capacity 178.7mAh/g, and first week coulombic efficiency is
83.5%, discharge capacity is 163.5mAh/g, capacity retention ratio 91.5% after recycling 50 weeks.Post-Ce-600 material
First week charge specific capacity is 229.4mAh/g, specific discharge capacity 196.8mAh/g, and first week coulombic efficiency is 80.9%, 50 weeks it
Specific discharge capacity afterwards is 195.3 mAh/g, capacity retention ratio 99.2%.
The performance test results that the battery assembled recycles 5 weeks respectively under different multiplying are as shown in figure 12, available
The 10C/0.1C=112.7mAhg of NCM material-1/177.8mAh·g-1=63.4%.And the 10C/ of post-Ce-600
0.1C=136.6mAhg-1/197mAh·g-1=69.4%.Show that post-Ce-600 material structure is more stable,
The capacity retention ratio recycled under high magnification high voltage has improvement relative to NCM material.
CV Dependence Results of the battery assembled after 2.75-4.5V is recycled 50 weeks are as shown in figure 16, with Figure 13 comparative example
CV curve comparison of the middle NCM material circulation after 50 weeks, it can be seen that NCM material circulation 50 weeks after in 2.5V-4.6V
Redox peaks in this interval range have not all been clearly, to illustrate that NCM material internal carries out redox contribution
The ion of capacity is seldom.And in post-Ce-600 material, redox peaks are still high-visible, it was demonstrated that its stratiform
It is structure-preserved preferable, so that one of the various transition metal ions still can restore tribute in 2.5-4.6V voltage range internal oxidition
Offer capacity.
The electrochemical impedance test result of material is as shown in figure 18 after the circulating battery assembled 50 weeks, and circulation is after 50 weeks
The interface resistance R of Post-Ce-600f=4.87 Ω, charge transfer resistance Rct=246.3 Ω.Post- as we can see from the figure
For the interface resistance and charge transfer resistance of Ce-600 material after same period electrochemistry circulation, the value added of resistance is minimum,
So the structural stability of Post-Ce-600 material be it is best, also correspond in Figure 11 its electrochemical cycle stability most
It is good.
It can be concluded that post-Ce-600 material surface is doped with Ce from these analysis data3+And it is coated with
CeO2, the chemical property of the material improves significantly relative to without modified NCM tertiary cathode material.
Embodiment 4
By cerous nitrate and NCM according to molar ratio Ce:NCM=0.01:1, it is added to ultrasound 1h in ethyl alcohol, then in mortar
It is uniform with ethyl alcohol mixed grinding, 5h is calcined at 750 DEG C, furnace cooling obtains final product, i.e., Ce is adulterated on a kind of surface layer3+And table
Layer cladding CeO2NCM tertiary cathode material, be denoted as post-Ce-750.
Test results are shown in figure 1 by the XRD of post-Ce-750, peak position in the main peak and comparative example in the present embodiment
It is almost the same, in 20-40 degree interval range, there is miscellaneous peak phase CeO2Peak generates, it is meant that there is CeO on high-nickel material surface2It generates.
According to XRD Rietveld refine as a result, in post-Ce-400 sample, Ni2+Occupy-place atomic percentage in Li layers is
1.66%, show Li+/Ni2+Mixing problem is improved.
Test results are shown in figure 6 by the SEM of post-Ce-750, it can be seen that and material sample can maintain its spherical morphology,
Radius is in 12 microns.
The EDS power spectrum of post-Ce-500 the result shows that, Ce is present in the material surface of post-Ce-600.
Ce3d profiling results in the XPS test of post-Ce-750 are as shown in figure 8, post-Ce- as we can see from the figure
The characteristic peak of corresponding Ce is fairly obvious in the XPS map of 750 corresponding Ce3d, can by be present in 882.1eV,
Corresponding v, v at 888.9eV, 898.1eV, 902.4eV, 907.0eV, 916.2eV ", v " ', U, U ", U " ' peak correspond to Ce4+
In the presence of, that is, there are CeO in material surface2.It proves to give birth to when Ce and NCM tertiary cathode material is calcined at 750 DEG C
At CeO2.In 888.0eV (V0), 885.4eV (V '), 897.8eV (u0), the position and 903.5eV (u ') in the XPS map of Ce3d
It sets, corresponds to Ce3+, it was demonstrated that there is Ce in post-Ce-750 sample particle3+Ion is present in surface layer intracell.Also illustrate
750 DEG C of calcination temperature can make Ce4+Into in the lattice of high-nickel material surface layer with Ni3+Redox reaction Ce occurs4++Ni3+
→Ce3++Ni2+, while CeO can be formed in nickelic particle surface2Protective layer stabilizes electrolyte/electrode interface, it is suppressed that table
Layer Li+/Ni2+Mixing, to improve the structural stability of NCM tertiary cathode material.
The Raman test result of post-Ce-750 shows: Raman tests the position of the corresponding combination energy in peak in 464cm-1
Correspond to CeO2, and combining can be in 261cm-1And 560cm-1The peak at place is its second order peak.
The Ni2p profiling results of the XPS test of post-Ce-750 are as shown in Figure 10, it can be seen that in the NCM material of comparative example
Ni is mostly with Ni in material2+Form exists, and in post-Ce-750 material, Ni is more with Ni3+Form exists.And it can be with
Observe Ni2p1/2The position at peak also obviously to the positional shift of higher combination energy, illustrates that the valent state of Ni increases.This is one
Determine to also demonstrate Li in post-Ce-750 material in degree+/Ni2+Mixing is inhibited, and Ce3+Doping enters transition metal
In layer, this all will be helpful to NCM tertiary cathode material and maintains lattice structure to stablize under the conditions of height de- lithium state.
It is assembled into CR2025 button cell using post-Ce-750 as positive electrode, and carries out electrochemical property test.
The battery assembled recycles 50 weeks chemical property results such as under 2.75-4.5V, 25 DEG C, 0.2C test condition
Shown in Figure 11, the first all charging capacitys of NCM material are 214mAh/g, specific discharge capacity 178.7mAh/g, and first week coulombic efficiency is
83.5%, discharge capacity is 163.5mAh/g, capacity retention ratio 91.5% after recycling 50 weeks.Post-Ce-750 material
First week charge specific capacity is 248.9mAh/g, specific discharge capacity 199.1mAh/g, after first week coulombic efficiency is 80%, 50 weeks
Specific discharge capacity be 189 mAh/g, capacity retention ratio 94.9%.
The performance test results that the battery assembled recycles 5 weeks respectively under different multiplying are as shown in figure 12, available
The 10C/0.1C=112.7mAhg of NCM material-1/177.8mAh·g-1=63.4%.And the 10C/ of post-Ce-750
0.1C=142.7mAhg-1/210.4mAh·g-1=67.8%.Show that post-Ce-750 material structure is more stable,
The capacity retention ratio recycled under high magnification high voltage has improvement relative to NCM material.
CV Dependence Results of the battery assembled after 2.75-4.5V is recycled 50 weeks are as shown in figure 17, with Figure 13 comparative example
CV curve comparison of the middle NCM material circulation after 50 weeks, it can be seen that NCM material circulation 50 weeks after in 2.5V-4.6V
Redox peaks in this interval range have not all been clearly, to illustrate that NCM material internal carries out redox contribution
The ion of capacity is seldom.And in post-Ce-750 material, redox peaks are still high-visible, it was demonstrated that its stratiform
It is structure-preserved preferable, so that one of the various transition metal ions still can restore tribute in 2.5-4.6V voltage range internal oxidition
Offer capacity.Simultaneously it can be seen that post-Ce-750 material oxidation reduction peak voltage difference is little, available right in CV curve
The polarization recycled with electrochemistry answered is little.
The electrochemical impedance test result of material is as shown in figure 18 after the circulating battery assembled 50 weeks, and circulation is after 50 weeks
The interface resistance R of Post-Ce-750f=5.55 Ω, charge transfer resistance Rct=393.3 Ω.Post-Ce- after recycling 50 weeks
The interface resistance and charge transfer resistance of 750 materials have obtained being obviously reduced a lot relative to NCM material.Illustrate modified by Ce
Material afterwards is more stable, and in electrochemistry cyclic process, impedance increases slow.
It can be concluded that post-Ce-750 material surface is doped with Ce from these analysis data3+And it is coated with
CeO2, the chemical property of the material improves significantly relative to without modified NCM tertiary cathode material.
Embodiment 5
By cerous nitrate and NCM according to molar ratio Ce:NCM=0.005:1, it is added to ultrasound 1h in ethyl alcohol, then in mortar
It is middle uniform with ethyl alcohol mixed grinding, 5h is calcined at 500 DEG C, furnace cooling obtains final product, i.e., Ce is adulterated on a kind of surface layer3+And
Surface layer coats CeO2NCM tertiary cathode material.
It is assembled into CR2025 button cell using material prepared by the present embodiment as positive electrode, and carries out electrochemistry
It can test.Constant current charge-discharge test is carried out under 2.75V~4.5V voltage range, 25 DEG C and 0.2C multiplying power, first Zhou Fang electricity holds
Amount is 193.2mAh/g, and discharge capacity of the circulation after 50 weeks is 178.7mAh/g, capacity retention ratio 92.5%.
Embodiment 6
By cerous nitrate and NCM according to molar ratio Ce:NCM=0.02:1, it is added to ultrasound 1h in ethyl alcohol, then in mortar
It is uniform with ethyl alcohol mixed grinding, 5h is calcined at 500 DEG C, furnace cooling obtains final product, i.e., Ce is adulterated on a kind of surface layer3+And table
Layer cladding CeO2NCM tertiary cathode material.
It is assembled into CR2025 button cell using material prepared by the present embodiment as positive electrode, and carries out electrochemistry
It can test.Constant current charge-discharge test is carried out under 2.75V~4.5V voltage range, 25 DEG C and 0.2C multiplying power, first Zhou Fang electricity holds
Amount is 196.3mAh/g, and discharge capacity of the circulation after 50 weeks is 179.8mAh/g, capacity retention ratio 91.6%.
Embodiment 7
By cerous nitrate and NCM according to molar ratio Ce:NCM=0.03:1, it is added to ultrasound 2h in ethyl alcohol, then in mortar
It is uniform with ethyl alcohol mixed grinding, 5h is calcined at 500 DEG C, furnace cooling obtains final product, i.e., Ce is adulterated on a kind of surface layer3+And table
Layer cladding CeO2NCM tertiary cathode material.
It is assembled into CR2025 button cell using material prepared by the present embodiment as positive electrode, and carries out electrochemistry
It can test.Constant current charge-discharge test is carried out under 2.75V~4.5V voltage range, 25 DEG C and 0.2C multiplying power, first Zhou Fang electricity holds
Amount is 189.7mAh/g, and discharge capacity of the circulation after 50 weeks is 178.2mAh/g, capacity retention ratio 93.9%.
It is demonstrated experimentally that the sample that calcination temperature is 500~750 DEG C, surface can be tested by XRD, XPS, Raman etc.
Means have detected Ce3+And CeO2In the presence of, and pass through electro-chemical test it may be concluded that Ce is adulterated on surface layer3+And it coats
CeO2NCM tertiary cathode material discharge capacity and stable circulation performance obviously improved.It can also by CV and EIS test
To find out, Ce is adulterated on surface layer3+And cladding CeO2NCM tertiary cathode material electrochemistry circulation after structure it is more stable, polarization more
It is small, it is all corresponding smaller that resistance and interfacial charge transfer resistance are not compensated.
It is by the test result of above-mentioned comparative example and embodiment it is found that provided by the invention in NCM tertiary cathode material
Surface layer generates CeO by control synthesis condition2, and by Ce3+Doping enters the method in the transition metal layer of surface layer lattice, tool
There is the Ce of strong oxidizing property4+It initially enters inside nickelic layer structure, redox reaction Ce occurs4++Ni2+→Ce3++Ni3+, will
Ni in lattice surface layer2+It is oxidized to Ni3+, while Ce4+Itself is reduced into Ce3+It is stable in the presence of transition metal layer, plays stabilization
Stratiform frame structure, while reducing the Li in positive electrode surface layer+/Ni2+Effect；Surface layer CeO2Cladding stabilize electrolysis
Liquid/electrode interface structure；It can significantly improve the high rate performance and stable circulation performance of NCM tertiary cathode material, especially
It is more preferably significant to the chemical property improvement under high voltage high magnification, and low cost of raw materials, asepsis environment-protecting, it is whole
A process flow is simple, efficiently, environmental protection, experiment condition is wide in range, high reliablity, has good prospects for commercial application.
The present invention includes but is not limited to above embodiments, it is all carried out under the principle of spirit of that invention it is any equivalent
Replacement or local improvement, all will be regarded as within the scope of the present invention.
Claims (7)
1. Ce is adulterated on a kind of surface layer3+And surface layer coats CeO2NCM tertiary cathode material, it is characterised in that: the materials chemistry
Formula is wCeO2-Li[Ni1-x-y-zMnxCoyCez]O2, wherein x>0, y>0, z>0, w>0,0.8<1-x-y-z<1,0<x+y+z<0.2,
0.005≤w+z≤0.03。
2. Ce is adulterated on a kind of surface layer as described in claim 13+And surface layer coats CeO2NCM tertiary cathode material preparation side
Method, it is characterised in that: the method comprises the following steps:
By cerous nitrate and NCM tertiary cathode material 1~2h of ultrasound in ethanol, then grinding is uniform, forges at 500~750 DEG C
4~6h is burnt, furnace cooling obtains a kind of surface layer doping Ce3+And surface layer coats CeO2NCM tertiary cathode material；
Wherein, the chemical formula of NCM tertiary cathode material is Li [Ni1-x-yMnxCoy]O2, x>0, y>0,0.8<1-x-y<1,0<x+y<
0.2；
The molar ratio of Ce and NCM tertiary cathode material is 0.005~0.03:1 in cerous nitrate.
3. Ce is adulterated on a kind of surface layer as claimed in claim 23+And surface layer coats CeO2NCM tertiary cathode material preparation side
Method, it is characterised in that: the molar ratio of Ni, Mn, Co are 0.869:0.0921:0.0389 in NCM tertiary cathode material.
4. Ce is adulterated on a kind of surface layer as claimed in claim 23+And surface layer coats CeO2NCM tertiary cathode material preparation side
Method, it is characterised in that: the molar ratio of cerous nitrate and NCM tertiary cathode material is 0.01:1.
5. Ce is adulterated on a kind of surface layer as claimed in claim 23+And surface layer coats CeO2NCM tertiary cathode material preparation side
Method, it is characterised in that: calcination temperature is 600 DEG C.
6. Ce is adulterated on a kind of surface layer as claimed in claim 23+And surface layer coats CeO2NCM tertiary cathode material preparation side
Method, it is characterised in that: calcination time 5h.
7. a kind of lithium ion secondary battery, it is characterised in that: the positive electrode of the battery is a kind of table described in claim 1
Layer doping Ce3+And surface layer coats CeO2NCM tertiary cathode material.
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| CN111009656A (en) * | 2019-12-05 | 2020-04-14 | 凤阳泰和九思科技有限公司 | Preparation method of rare earth metal doped high-nickel ternary battery positive electrode material |
| CN110911687A (en) * | 2019-12-09 | 2020-03-24 | 中南大学 | Rare earth element modified lithium ion battery positive electrode material, and preparation method and application thereof |
| CN113258040A (en) * | 2020-03-27 | 2021-08-13 | 深圳市贝特瑞纳米科技有限公司 | Positive electrode material, preparation method thereof and secondary lithium battery |
| WO2021190559A1 (en) * | 2020-03-27 | 2021-09-30 | 深圳市贝特瑞纳米科技有限公司 | Positive electrode material and preparation method therefor, and secondary lithium battery |
| CN113258059A (en) * | 2021-04-27 | 2021-08-13 | 浙江帕瓦新能源股份有限公司 | Multi-modified lithium ion battery positive electrode material and preparation method thereof |
| CN114628663A (en) * | 2022-04-21 | 2022-06-14 | 华鼎国联四川电池材料有限公司 | Cerium-doped ternary cathode material and preparation method thereof |
| CN114628663B (en) * | 2022-04-21 | 2024-04-09 | 华鼎国联四川电池材料有限公司 | Cerium doped ternary cathode material and preparation method thereof |
| CN115000380A (en) * | 2022-06-27 | 2022-09-02 | 中国科学院青海盐湖研究所 | High nickel ternary positive electrode material, CeO 2 Self-coated high-nickel ternary positive electrode material and preparation method thereof |
| CN116314832A (en) * | 2023-05-23 | 2023-06-23 | 中自环保科技股份有限公司 | Sodium ion battery positive electrode slurry, pole piece and pole piece preparation method |
| CN116314832B (en) * | 2023-05-23 | 2023-07-21 | 中自环保科技股份有限公司 | Sodium ion battery positive electrode slurry, pole piece and pole piece preparation method |
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