Lithium nickel-based oxide as a cathode active material for lithium batteries

Abstract

The present disclosure relates to a cathode active material for lithium batteries, comprising lithium (Li), M, and oxygen (O), wherein M comprises phosphorous (P) and silicium (Si) and 60 at% or more of nickel (Ni). Moreover, a battery comprising a cathode active material according to this disclosure presents an improved stability and capacity retention. The present disclosure also relates to a method for manufacturing said cathode active material, and a battery comprising said cathode active material, for an electric vehicle or hybrid electric vehicle.

Description

LITHIUM NICKEL-BASED OXIDE AS A CATHODE ACTIVE MATERIAL FOR LITHIUM BATTERIESTECHNICAL FIELD

[0001] The present disclosure relates to a cathode active material for lithium batteries, comprising lithium (Li), M, and oxygen (O), wherein M comprises phosphorous (P) and silicium (Si) and 60 at% or more of nickel (Ni). Moreover, a battery comprising a cathode active material according to this disclosure presents an improved stability and capacity retention. The present disclosure also relates to a method for manufacturing said cathode active material, and a battery comprising said cathode active material, for an electric vehicle or hybrid electric vehicle.BACKGROUND ART

[0002] Modern batteries require high energy density as well as long cycle life, especially for automotive applications. Currently, NMC (lithium-nickel-manganese-cobalt oxide) or NCA (lithium-nickel-cobalt-aluminum oxide) are the most promising cathode active materials used in batteries for an electric vehicle or hybrid electric vehicle.

[0003] NMC materials comprise particles, usually of spherical shape, and according to the formula Lii+a(NibMncCod)i-aO2, wherein b+c+d = 1. Due to the lower price of nickel compared to cobalt, the NMC material with a higher Ni content and a lower Co content results in a cheaper cathode active material. In the context of this disclosure, the term "high Ni NMC" refers to NMC materials wherein the Ni content (b in the previous formula above) is at least 0.6, for example LiNi0.6Mn0.2Co0.2O2. The term "very high Ni NMC" refers to NMC materials wherein b is at least 0.8, for example LiNi0.90Mn0.05Co0.05O2.

[0004] The reversible capacity of the NMC material tends to increase as the Ni content increases. For example, NMC 622 (LiNi0.6Mn0.2Co0.2O2) presents a higher reversible capacity compared to NMC 442 (LiNi0.4Mn0.4Co0.2O2), meaning that less weight or volume is required to achieve a certain energy demand.

[0005] However, as the Ni content increases, the amount of impurities present in the cathode active material also increases, see US7648693. Impurities, such as hydroxide or carbonate salts known as soluble bases, often remain in the cathode active material causing gas generation in the cells (bulging), resulting in poor stability, poor cycling performance and raising safety issues.

[0006] Several alternatives have been investigated to improve the stability of the NMC composition, for example by adding metals or semimetals to the cathode active material, see Zahra Ahaliabadeh et al., Journal of Power Sources, 2022, 540, 231633.

[0007] In particular, transition metals, such as Mg, Al, Ti, Ta, Nb and / or Mo, have been widely investigated to improve the stability of cathode active materials, see Wuwei Yan et al, Journal of Alloys and Compounds, 2020, 819, 153048.

[0008] Huang Yuan-Jun et al, Material Chemistry and Physics, 2007, 106, on pages 354-359 discloses a cathode active material comprising silicium, according to the formula Li(Nii / 3Mni / 3Coi / 3)o.96Sio.o40i.96Fo.o4. The resulting cathode active material presents an improved discharge capacity and cycling retention.

[0009] Jiankun Chen et al, Electrochimica Acta, 2017, 228, on pages 167-174 discloses a cathode active material according to the formula LiNio.sMno^asSio.oisCL with an improved electrochemical performance when compared to LiNio.5Mno.5O2. However, this disclosure also states that Si-addition is not an effective manner of improving the performance of a lithium battery.

[0010] Therefore, there is a need in the art for a cathode active material for lithium batteries with improved stability and / or improved electrochemical properties, such as capacity retention.

[0011] Additionally, there is a need for a method for manufacturing the above-mentioned cathode active material, and a battery comprising said cathode active material.SUMMARY

[0012] The present disclosure provides a cathode active material for lithium batteries, comprising Li, M, and O, wherein M comprises:Ni in an atomic content x, wherein 0.60 < x < 0.98 relative to M,Mn in an atomic content y, wherein 0.005 < y < 0.30 relative to M,Co in an atomic content z, wherein 0.005 < z < 0.30 relative to M,P in an atomic content a, wherein 0.00001 < a < 0.07 relative to M;Si in an atomic content b, wherein 0.00005 < b < 0.01 relative to M,wherein x, y, z, a and b are measured by ICP-OES, and wherein the Li / M atomic ratio is between 0.8 to 1.5.

[0013] It has been found that a cathode active material according to this disclosure might have an improved stability and / or capacity retention when compared to the corresponding cathode active material without Si and P, see the results section.

[0014] The present disclosure also provides a method for manufacturing said cathode active material, comprising the following steps:1) mixing a metal-based precursor with a first lithium source to obtain a first mixture, wherein the Li / M atomic ratio of the first mixture is lower than 1;2) heating the first mixture at a temperature between 600 °C and 1000 °C to obtain a first heated mixture;3) mixing the first heated mixture with a second lithium source to obtain a second mixture;and4) heating the second mixture at a temperature between 400 °C and 1000 °C to obtain the cathode active material.

[0015] The present disclosure also provides a battery comprising said cathode active material.

[0016] The present disclosure also provides the use of said battery in rechargeable batteries across a wide range of electrically powered devices and systems. Electrically powered devices and systems comprising the battery include consumer electronics such as portable computers, tablets, mobile phones, and telecommunication devices. Industrial applications encompass power tools, mobile machinery, and robotic devices. In the domain of energy infrastructure, the battery may be employed in energy storage systems and uninterruptible power supply (UPS) systems.DETAILED DESCRIPTION

[0017] In the following detailed description, preferred embodiments are described in detail to enable practice of the present invention. Although the present invention is described with reference to these specific preferred embodiments, it will be understood that the present invention is not limited to these preferred embodiments. In contrast, the present invention includes numerous alternatives, modifications and equivalents as will become apparent from consideration of the following detailed description.

[0018] The following terms are intended to have the meaning presented below and are useful in understanding the description and intended scope of this disclosure.

[0019] The term "comprising", as used herein and in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps.It needs to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a composition comprising components A and B" should not be limited to compositions consisting only of components A and B. It means that with respect to the present disclosure, the only relevant components of the composition are A and B. Accordingly, the terms "comprising" and "including" encompass the more restrictive terms "consisting essentially of" and "consisting of".

[0020] The term "cathode active material" (also known as CAM or positive electrode active material) refers to a material which is electrochemically active in a positive electrode or cathode. By active material, it must be understood to be capable of capturing and releasing Li ions when subjected to a voltage change over a predetermined period.

[0021] In the framework of the present disclosure, the content of a particular element of the periodic table signifies atomic percentage. The at% or "atomic percent" of a given element expression of a concentration means how many percent of all atoms in the concerned compound are atoms of said element. The designation at% is equivalent to mol% or "molar percent".

[0022] As used herein, a range of values "between X and Y" include the endpoints of X and Y.

[0023] The term "about" refers to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of + / -20% or less, preferably + / -10% or less, more preferably + / -5% or less, even more preferably + / -1% or less, and still more preferably + / -0.1% or less of and from the specified value, in so far such variations are appropriate to perform in the present disclosure. However, it is to be understood that the value to which the modifier "about" refers is itself also specifically disclosed.Cathode Active Material

[0024] In a first aspect, the present disclosure relates to a cathode active material for lithium batteries, wherein the cathode active material comprises Li, M, and O, wherein M comprises:Ni in an atomic content x, wherein 0.60 < x < 0.98 relative to M;Mn in an atomic content y, wherein 0.005 < y < 0.30 relative to M;Co in an atomic content z, wherein 0.005 < z < 0.30 relative to M;P in an atomic content a, wherein 0.00001 < a < 0.07 relative to M;Si in an atomic content b, wherein 0.00005 < b < 0.01 relative to M;wherein x, y, z, a and b are measured by ICP-OES, and wherein the Li / M atomic ratio is between 0.8 to 1.5.

[0025] In one embodiment, the cathode active material comprises Li, M, and O, wherein M comprises Ni in an atomic content x, wherein 0.60 < x < 0.98 relative to M, Mn in an atomic content y, wherein 0.005 < y < 0.30 relative to M, Co in an atomic content z, wherein 0.005 < z < 0.30 relative to M, P in an atomic content a, wherein 0.00001 < a < 0.07 relative to M, and Si in an atomic content b, wherein 0.00005 < b < 0.01 relative to M, wherein x, y, z, a and b are measured by ICP-OES, and x+y+z+a + b is > 0.95. In another embodiment, x+y+z+a + b is > 0.98. In another embodiment, x+y+z+a + b is > 0.99. In another embodiment, x+y+z+a + b is 1.

[0026] In one embodiment, the cathode active material comprises Ni in an atomic content x, wherein 0.70 < x < 0.98 relative to M. In another embodiment, 0.80 < x < 0.98 relative to M. In another embodiment, 0.85 < x < 0.95 relative to M. For example, x is 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94 or 0.95, relative to M.

[0027] In one embodiment, the cathode active material comprises Mn in an atomic content y, wherein 0.01 < y < 0.15 relative to M. In another embodiment, 0.01 < y < 0.10 relative to M. For example, y is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.10 relative to M.

[0028] In one embodiment, the cathode active material comprises Co in an atomic content z, wherein 0.01 < z < 0.15 relative to M. In another embodiment, 0.01 < z < 0.10 relative to M. For example, z is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.10, relative to M.

[0029] In one embodiment, the cathode active material comprises P in an atomic content a, wherein 0.00001 < a < 0.007 relative to M. In another embodiment, 0.00005 < a < 0.005 relative to M. In another embodiment, 0.00008 < a < 0.002 relative to M. In another embodiment, 0.0001 < a < 0.001 relative to M. For example, a is 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008, 0.0009 or 0.001, relative to M.

[0030] In one embodiment, the cathode active material comprises Si in an atomic content b, wherein 0.00005 < b < 0.005 relative to M. In another embodiment, 0.00007 < b < 0.001 relative to M. In another embodiment, 0.00007 < b < 0.0005 relative to M. For example, b is 0.00007, 0.00008, 0.00009, 0.0001, 0.00015, 0.0002, 0.00025, 0.0003, 0.00035, 0.0004, 0.00045 or 0.0005, relative to M.

[0031] In one embodiment of the cathode active material, the Li / M atomic ratio is between 0.9 and 1.2. In another embodiment, the Li / M atomic ratio is between 0,95 and 1.1. For example, the Li / M atomic ratio is 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04 or 1.05.

[0032] In one embodiment, the cathode active material comprises Ni in an atomic content x, wherein 0.70 < x < 0.98 relative to M; Mn in an atomic content y, wherein 0.01 < y < 0.15 relative to M; Co in an atomic content z, wherein 0.01 < z < 0.15 relative to M; P in an atomic content a, wherein 0.00008 < a < 0.002; Si in an atomic content b, wherein 0.00007 < b < 0.0005 relative to M; and a Li / M atomic ratio between 0.9 and 1.2.

[0033] In one embodiment, the cathode active material is according to the formula (I) LiwNixiMnyiCoziPaiSibiO2, wherein 0.80 < w < 1.50; 0.60 < xl < 0.98; 0.005 < yl < 0.30; 0.005 < zl < 0.30; 0.00001 < al < 0.07; and 0.00005 < bl < 0.01, wherein xl, yl, zl, al and bl are measured by ICP-OES, and xl+yl+zl+al + bl > 0.95. In another embodiment, xl+yl+zl+al + bl is > 0.98. In another embodiment, xl+yl+zl+al + bl is > 0.99. In another embodiment, xl+yl+zl+al + bl is 1.

[0034] In one embodiment, the cathode active material is according to the formula (I), wherein 0.70 < xl < 0.98. In another embodiment, 0.80 < xl < 0.98. In another embodiment, 0.85 < xl < 0.95. For example, xl is 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94 or 0.95.

[0035] In one embodiment, the cathode active material is according to the formula (I), wherein 0.01 < yl < 0.15. In another embodiment, 0.01 < yl < 0.10. For example, yl is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.10.

[0036] In one embodiment, the cathode active material is according to the formula (I), wherein 0.01 < zl < 0.15. In another embodiment, 0.01 < zl < 0.10. For example, zl is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.10.

[0037] In one embodiment, the cathode active material is according to the formula (I), wherein 0.00001 < al < 0.007. In another embodiment, 0.00005 < al < 0.005. In another embodiment, 0.00008 < al < 0.002. In another embodiment, 0.0001 < al < 0.001. For example, al is 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008, 0.0009 or 0.001.

[0038] In one embodiment, the cathode active material is according to the formula (I), wherein 0.00005 < bl < 0.005. In another embodiment, 0.00007 < bl < 0.001. In another embodiment, 0.00007 < bl < 0.0005. For example, bl is 0.00007, 0.00008, 0.00009, 0.0001, 0.00015, 0.0002, 0.00025, 0.0003, 0.00035, 0.0004, 0.00045 or 0.0005.

[0039] In one embodiment, the cathode active material is according to the formula (I), wherein 0.9 < w < 1.2. In another embodiment, 0.95 < w < 1.1. For example, w is 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04 or 1.05.

[0040] In one embodiment, the cathode active material is according to the formula (I), wherein 0.9 < w < 1.2; 0.70 < xl < 0.98; 0.01 < yl < 0.15; 0.01 < zl < 0.15; 0.00008 < al < 0.002; and 0.00007 < bl < 0.0005.

[0041] In one embodiment, the cathode active material comprises IJ2CO3 in a mass content equal or lower to 0.4 % relative to the total mass of the cathode active material, as measured by titration analysis method. In another embodiment, the IJ2CO3 mass content is equal or lower to 0.35 %.

[0042] In one embodiment, the cathode active material comprises LiOH in a mass content equal or lower to 0.3 % relative to the total mass of the cathode active material, as measured by titration analysis method. In another embodiment, the LiOH mass content is equal or lower to 0.2 %.

[0043] In one embodiment, the cathode active material comprises a total base content equal or lower to 300 pmol per gram of the cathode active material, as measured by titration analysis method. In another embodiment the total base content is equal or lower to 200 pmol per gram of the cathode active material. In another embodiment, the total base content is equal or lower to 170 pmol per gram of the cathode active material.

[0044] In one embodiment, the cathode active material has a specific surface area between 0.1 m2 / g and 0.8 m2 / g. In another embodiment, the specific surface is between 0.4 m2 / g and 0.7 m2 / g. In another embodiment, the specific surface area is between 0.6 m2 / g and 0.7 m2 / g. For example, 0.60 m2 / g, 0.61 m2 / g, 0.22 m2 / g, 0.62 m2 / g, 0.63 m2 / g, 0.64 m2 / g, 0.65 m2 / g, 0.66 m2 / g, 0.67 m2 / g, 0.68 m2 / g, 0.69 m2 / g or 0.70 m2 / g.

[0045] In one embodiment, the cathode active material comprises particles having a crystalline size between 80 nm and 170 nm, as measured by XRD Rietveld refinement. In another embodiment, the crystalline size is between 120 nm and 160 nm. In anotherembodiment, the crystalline size is between 140 nm and 150 nm. For example, 140 nm, 141 nm, 142 nm, 143 nm, 144 nm, 145 nm, 146 nm, 147 nm, 148 nm, 149 nm or 150 nm.

[0046] In one embodiment, the cathode active material is according to the formula (I), wherein 0.9 < w < 1.2; 0.80 < xl < 0.98; 0.01 < yl < 0.15; 0.01 < zl < 0.15; 0.00008 < al < 0.002; and 0.00007 < bl < 0.0005, and having a IJ2CO3 mass content lower than 0.35 %, a LiOH mass content lower than 0.2 %, relative to the total mass of the cathode active material, a specific surface area lower than 0.7 m2 / g, and a crystalline size between 120 nm and 150 nm.

[0047] It has been found that a lithium battery comprising a cathode active material according to this disclosure has a higher stability than the corresponding lithium battery comprising a cathode active material without P and Si. Additionally, a cathode active material according to this disclosure also shows an improved irreversible capacity when compared to the corresponding cathode active material without P and Si, see Table II below.Method for Manufacturing a Cathode Active Material

[0048] In a second aspect, the present disclosure relates to a method for manufacturing the cathode active material according to the first aspect, wherein the method comprises the following steps:1) mixing a metal-based precursor with a first lithium source to obtain a first mixture, wherein the Li / M ratio of the first mixture is lower than 1;2) heating the first mixture at a temperature between 600 °C and 1000 °C to obtain a first heated mixture;3) mixing the first heated mixture with a second lithium source to obtain a second mixture;and4) heating the second mixture at a temperature between 400 °C and 1000 °C to obtain the cathode active material.

[0049] The cathode active material according to the first aspect of the present disclosure may be obtained by a method according to the second aspect of the present disclosure. In detail, the technical features of the first aspect of the present disclosure, e.g., the specific composition of the cathode active material, specific surface area, and the content of IJ2CO3 and LiOH may be achieved by the method according to the second aspect of the present disclosure.

[0050] In one embodiment of the method, the metal-based precursor comprises Ni, Mn, Co, P and Si. In another embodiment, the metal-based precursor is according to the formula (II)Nix2Mny2Coz2Pa2Sib2(OH)2, wherein 0.60 < x2 < 0.98; 0.005 < y2 < 0.30; 0.005 < z2 < 0.30; 0.00001 < a2 < 0.07; and 0.00005 < b2 < 0.01; wherein x2, y2, z2, a2 and b2 are measured by ICP-OES, and x2+y2+z2+a2 + b2 > 0.95. In another embodiment, x2+y2+z2+a2+b2 is > 0.98. In another embodiment, x2+y2+z2+a2+b2 is > 0.99. In another embodiment, x2+y2+z2+a2 + b2 is 1.

[0051] In one embodiment of the method, the metal-based precursor is according to formula (II), wherein 0.70 < x2 < 0.98. In another embodiment, 0.80 < x2 < 0.98. In another embodiment, 0.85 < x2 < 0.95. For example, x2 is 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94 or 0.95.

[0052] In one embodiment of the method, the metal-based precursor is according to formula (II), wherein 0.01 < y2 < 0.15. In another embodiment, 0.01 < y2 < 0.10. For example, y2 is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.10.

[0053] In one embodiment of the method, the metal-based precursor is according to formula (II), wherein 0.01 < z2 < 0.15. In another embodiment, 0.01 < z2 < 0.10. For example, z2 is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.10.

[0054] In one embodiment of the method, the metal-based precursor is according to the formula (II), wherein 0.00001 < a2 < 0.007. In another embodiment, 0.00005 < a2 < 0.005. In another embodiment, 0.00008 < a2 < 0.002. In another embodiment, 0.0001 < a2 < 0.001. For example, a2 is 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008, 0.0009 or 0.001.

[0055] In one embodiment of the method, the metal-based precursor is according to the formula (II), wherein 0.00005 < b2 < 0.005. In another embodiment, 0.00007 < b2 < 0.001. In another embodiment, 0.00007 < b2 < 0.0005. For example, b2 is 0.00007, 0.00008, 0.00009, 0.0001, 0.00015, 0.0002, 0.00025, 0.0003, 0.00035, 0.0004, 0.00045 or 0.0005.

[0056] In one embodiment of the method, the metal-based precursor is according to formula (II), wherein 0.70 < x2 < 0.98; 0.01 < y2 < 0.15; 0.01 < z2 < 0.15; 0.00008 < a2 < 0.002; and 0.00007 < b2 < 0.0005.

[0057] In one embodiment of the method, the first lithium source is LiOH, IJ2CO3 or a mixture thereof.

[0058] In one embodiment of the method, the second lithium source is LiOH, IJ2CO3 or a mixture thereof.

[0059] In one embodiment of the method, the first and the second lithium source is LiOH.

[0060] In one embodiment of the method, the first mixture is heated at a temperature between 700 °C and 1000 °C. For example, at 700 °C, 750 °C, 800 °C, 830 °C, 850 °C, 870 °C, 900 °C, 950 °C or 1000 °C.

[0061] In one embodiment of the method, the first mixture is heated for a time between 2 hours and 20 hours. In another embodiment, for a time between 5 hours to 12 hours. For example, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours.

[0062] In one embodiment of the method, the first heated mixture is mixed with 0.5 mol% of a cobalt source, relative to Ni, Mn and Co, to obtain a mixture A. In another embodiment, the first heated mixture is mixed with 0.5 mol% of CoSO4, relative to Ni, Mn and Co.

[0063] In one embodiment, the method further comprises the step of subjecting the mixture A to wet ball milling to obtain a milled mixture comprising a solid phase and a liquid phase.

[0064] In one embodiment, the method further comprises the step of separating the solid phase from the liquid phase by filtering and drying the solid phase, to obtain a solid-state intermediate. In another embodiment, the drying step is performed under N2 atmosphere and at temperature between 100 °C and 200 °C. In another embodiment, the drying step is performed under N2 atmosphere and at 130 °C, 140 °C, 150 °C, 160 °C or 170 °C.

[0065] In one embodiment of the method, the second mixture is heated at a temperature between 450 °C and 800 °C. For example, at 450 °C, 500 °C, 550 °C, 600 °C, 650 °C, 700 °C, 740 °C, 750 °C, 755 °C, 760 °C, 770 °C or 800 °C.

[0066] In one embodiment of the method, the second mixture is heated for a time between 2 hours and 15 hours. In another embodiment, for a time between 5 hours and 10 hours. For example, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours.

[0067] In one embodiment, the method for manufacture the cathode active material comprises the following step:1) mixing a metal-based precursor with LiOH and 0.125 mol% of ZrO? to obtain a first mixture, wherein the Li / M ratio of the first mixture is lower than 1;2) heating the first mixture at a temperature between 600 °C and 1000 °C for a time between 6 to 10 hours, to obtain a first heated mixture;3) mixing the first heated mixture with 0.5 mol% of CoSO4 relative to Ni, Mn, and Co, to obtain a mixture A;4) subjecting the mixture A to wet milling to obtain a milled mixture comprising a solid phase and a liquid phase;5) separating the solid phase by filtering and drying the solid phase at 150 °C and under N2 atmosphere, to obtain a solid-state intermediate;6) mixing the solid-state intermediate with LiOH, 0.125 mol% of ZrO? and 0.5 mol% of CO3O4, relative to Ni, Mn and Co, to obtain a second mixture having a Li / (Ni, Mn, and Co) ratio about 1;7) heating the second mixture at a temperature between 700°C and 800 °C for a time between 8 and 10 hours, to obtain a second heated mixture;8) grinding and sieving the second heated mixture with AI2O3 to obtain a mixture B, wherein the amount of Al in the mixture B is 500 ppm relative to Ni, Mn, Co;9) mixing the mixture B with H3BO3 and WO3 to obtain a mixture C, wherein the amount of B in the mixture C is 500 ppm relative to Ni, Mn, Co; and the amount of W in the mixture C is 4500 ppm relative to Ni, Mn, Co;10) heating the mixture C at a temperature between 350 °C and 400 °C for a time between 8 and 10 hours, to obtain a heated mixture C; and11)grinding and sieving the heated mixture C with AI2O3 to obtain a cathode active material, wherein the amount of Al is 500 ppm relative to Ni, Mn, Co.Battery

[0068] In a third aspect, the present disclosure relates to a battery comprising a cathode active material suitable for use in rechargeable batteries across a wide range of electrically powered devices and systems. The battery may be integrated into various applications that utilize electricity as a primary or auxiliary energy source.

[0069] Electrically powered devices and systems comprising the battery include consumer electronics such as portable computers, tablets, mobile phones, and telecommunication devices. Industrial applications encompass power tools, mobile machinery, and robotic devices. In the domain of energy infrastructure, the battery may be employed in energy storage systems and uninterruptible power supply (UPS) systems.

[0070] Transportation applications include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), extended-range electric vehicles (EREVs), and fuel cell electric vehicles (FCEVs). These vehicles may be designed for passenger or freighttransport and may operate on ground, rail, marine, aerospace, or aviation platforms. Additionally, the battery may be used in two-wheeler transportation systems. Further applications include defense systems and medical devices, where reliable and compact energy sources are required.

[0071] In a fourth aspect, the present disclosure provides the use of a battery according to third aspect of this disclosure, in an electrically powered device or system selected from the group consisting of: a portable computer, a tablet, a mobile phone, a telecommunication device, a power tool, mobile machinery, a robotic device, an energy storage system, an uninterruptible power supply system, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an extended-range electric vehicle, a fuel cell electric vehicle, a twowheeler transportation system, a rail vehicle, a marine vessel, an aircraft, an aerospace system, a defense system, and a medical device.

[0072] As appreciated by a person skilled in the art, all embodiments directed to the cathode active material according to the first aspect may apply mutatis mutandis to the second, third and fourth aspect of the present disclosure. Additionally, this disclosure is intended to cover the combination of all embodiments listed above.EXPERIMENTAL ANALYSIS USED IN THE EXAMPLES

[0073] The following analysis methods are used in the Examples.A) Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES) analysis

[0074] The amount of Li, Ni, Co, Mn, P and Si in the cathode active material powder is measured with the ICP-OES method by using an Agilent ICP 720-ES (Agilent Technologies).2 grams of powder sample is dissolved into 10 mL of high purity hydrochloric acid (at least 37 wt% of HCI with respect to the total weight of solution) in an Erlenmeyer flask. The flask is covered by a glass and heated on a hot plate at 380 °C until complete dissolution of the powder. After being cooled to room temperature, the solution of the Erlenmeyer flask is poured into a 250 mL volumetric flask. Afterwards, the volumetric flask is filled with deionized water up to the 250 mL mark, followed by complete homogenization.B) Brunauer-Emmett-Teller (BET) analysis

[0075] The specific surface area (SSA) of the cathode active material is measured with the Brunauer-Emmett-Teller (BET) method by using a Micromeritics Tristar II 3020. A powder is heated at 300 °C under nitrogen (N2) gas for 1 hour prior to the measurement in order to remove adsorbed species. The dried powder is put into the sample tube. The sample is thende-gassed at 30 °C for 10 minutes. The instrument performs the nitrogen adsorption test at 77 K. By obtaining the nitrogen isothermal absorption / desorption curve, the total specific surface area of the sample in m2 / g is derived.C) Titration analysis

[0076] To measure the total base content present in a sample by pH titration, two steps are performed:(a) the reparation of solution, and(b) pH titration. The detailed explanation of each step is as follows:

[0077] Step (a): The preparation of solution: 4 grams of cathode active material powder is mixed within 100 mL of deionized water and stirred for 10 min in a sealed glass flask. After stirring, the powder suspension is filtered to obtain the solution.

[0078] Step (b): pH titration: 90 mL of the solution prepared in step (a) is used for pH titration by using 0.1M HCI. The flow rate is 0.5 mL / min, and the pH value is recorded every 3 seconds. The pH titration profile (pH value as a function of added HCI) shows two clear equivalence (or inflection) points. The first equivalence point (corresponding to a HCI quantify of EPl) at around pH 7.4 results from the reaction of OH-and CDs2-with H+. The second equivalence point (corresponding to a HCI quantify of EP2) at around pH 4.7 results from the reaction of HCOs’ with H+. It is assumed that the dissolved base in deionized water is either LiOH (with a quantify 2x(EPl-EP2)) or Li2COs (with a quantify 2*(EP2-EP1)). The obtained values for LiOH and U2CO3 are the result of the reaction of the surface with deionized water.

[0079] The following definitions are used for data analysis: LiOH (wt%) is the weight percentage of the amount of LiOH over the amount of sample. Li2COs (wt%) is the weight percentage of the amount of Li2COs over the amount of sample. Total base content (pmol / g) is the amount of LiOH and Li2COs over a gram of sample, i.e. the amount of micro mol of HCI needed to neutralize the base of 1 gram of cathode active material.D) X-Ray diffraction (XRD) analysis

[0080] The X-ray diffraction pattern of the cathode active material is collected with a Rigaku X-Ray Diffractometer (Ultima IV) using a Cu-Ka radiation source (40kV, 40mA) emitting at a wavelength of 1.5418 A. The instrument configuration is set at: a 1° Soller slit (SS), a 10mm divergent height limiting slit (DHLS), a 1° divergence slit (DS) ad a 0.3 mm reception slit (RS). The diameter of the goniometer is 158 mm. For the XRD, diffraction patterns are obtained in the range of 50to 85° (20) with a scan speed of 1.0° per min and a step-size of 0.02° per scan. The crystallite sizes are calculated from the diffraction angle and the full widthat half maximum (FWHM) of the peak of the (104) plane obtained from the X-ray diffraction pattern using the known Scherrer equation :T: Crystallite size (nm), being the mean size of the ordered (crystalline) domains, which may be smaller or equal to the grain sizeK: Scherrer constant, 0.9A: X-ray wavelength (CuKa = 1.5418 A): Full width at half maximum (FWHM)0: XRD peak position, one half of 29

[0081] The peak of the (104) plane is observed at (around) 44.5±1° and (003) peak observed at (around) 18.6±1° which are assigned to a crystal structure with space group R-3m. All the Rietveld refinements of the XRD patterns were done with the FullProf program.E) Multi-layer pouch cell analysisEl) Multi-layer pouch cell preparation

[0082] 2000 mAh pouch-type cells are prepared as follows: the cathode active material powder, Super-P (Super-P, Imerys Graphite & Carbon) as positive electrode conductive agents, and polyvinylidene fluoride (PVDF S5130, Solvay) as a positive electrode binder are added to N-methyl-2-pyrrolidone (NMP) as a dispersion medium so that the mass ratio of the cathode active material powder, the positive electrode conductive agent Super P, the positive electrode binder is set at 95.0:3.0:2.0. Thereafter, the mixture is kneaded to prepare a positive electrode mixture slurry. The resulting positive electrode mixture slurry is then applied onto both sides of a positive electrode current collector, made of a 20 pm thick aluminum foil. The width of the applied area is 88.5 mm, and the length is 425 mm and 340 mm for each side. Typical loading weight of a cathode active material is about 14.8±1 mg / cm2. The electrode is then dried and calendared to target the electrode density of 3.3 g / cm3to 3.4 g / cm3. In addition, an aluminum plate serving as a positive electrode current collector tab is arc-welded to an end portion of the positive electrode.

[0083] Commercially available negative electrodes are used. In short, a mixture of artificial graphite, carbon (Super P (Imerys)), carboxy-methyl-cellulose-sodium, and styrene-butadiene-rubber, in a mass ratio of 95.0: 1.0: 1.5:2.5, is applied on both sides of a copper foil. A nickel plate serving as a negative electrode current collector tab is arc-welded to an end portion of the negative electrode. Typical loading weight of a negative electrode active material is about 10±l mg / m2.

[0084] Non-aqueous electrolyte is obtained by dissolving lithium hexafluorophosphate (LiPFe) salt at a concentration of 1.2 mol / L in a mixed solvent of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonated (DEC) in a volume ratio of 1: 1: 1. It contains 1.0 wt% lithium difluorophosphate (LiPO2F2), and 1.0 wt% vinylene carbonate (VC) as additives.

[0085] A sheet of the positive electrode, a sheet of the negative electrode, and a sheet of the microporous polymer separator (13 pm) interposed between them are spirally wound using a winding core rod in order to obtain a spirally wound electrode assembly. The assembly and the electrolyte are then put in an aluminum laminated pouch in an air-dry room with dew point of -50 °C, so that the flat pouch-type lithium secondary battery is prepared. The design capacity of the secondary battery is 2000 mAh when charged to 4.2 V. The cell testing procedure uses a 1 C current definition of 2000 mA / g.E2) Multi-layer pouch cell analysis

[0086] To measure the resistance and a recovered capacity by high temperature storage, the cell is fully charged and stored in a chamber at 60 °C for 6 months. Regular parameter test is conducted every month as follows; the cell the cells are fully charged and stored in a chamber at 60 °C for 1 month. After 1 month, the cells are removed from the chamber and cool down to room temperature. The recovered capacity is determined by 1 C discharge-charge-discharge steps and the discharge direct current resistance (called DCR) is measured at SOC50% with 1.5 C pulse for 10 seconds. The cell is fully charged again and restored in 60 °C chamber.

[0087] The recovered capacity is represented by the following equation:DQ2 after HT storageRecovered capacity = - - - x 100 (%)' Initial DQ2J

[0088] A higher percentage of recovered capacity indicates a higher cyclic stability, and therefore an improved battery performance.

[0089] 2000 mAh pouch-type cell prepared by above preparation method are fully charged to 4.2 V and inserted in an oven which is heated to 90 °C, then stays for 20 hours. At 90 °C, the charged positive electrode reacts with an electrolyte and creates gas. The evolved gas creates a bulging. The increase of thickness is measured after 20 hours.

[0090] The increase of thickness is represented by the following equation:Thickenss after storage — Thickness before storageIncrease of thickness = - - — - - — - - x 100 (%)Thickness before storage

[0091] A lower percentage of cell thickness increase indicates a lower generation gas inside the cell (less bulging), and therefore a higher stability of the cathode active material and better battery performance.Metal-based precursor for cathode active materialGeneral method to obtain a metal-based precursor

[0092] The metal-based precursor for a cathode active material according to this disclosure is obtained following this protocol.

[0093] Initially, boric acid (B(OH)3), sodium metasilicate (Na2SiOs), and sodium hexametaphosphate (Nae(PO3)e) are dissolved and mixed in water. The mixture containing B(OH)3, Na2SiC>3 and Nae(PO3)e is added to a NiSCk solution.

[0094] Then, the NiSCk solution is mixed with CoSO4, MnSC , NaOH and NH3. The resulting mixture contains 120 gr / L of nickel, cobalt, and manganese sulfate, 220 gr / L of NaOH, and 220 gr / L of NH3. The resulting mixture is stirred at 85 °C under a nitrogen atmosphere with gas flow of 0.5 L / min for a time between 20 and 30 hours.

[0095] The resulting mixture is filtered, and the solid is dried to obtain the corresponding metal-based precursor.

[0096] The following metal-based precursors were obtained following the above-described method. All the precursors comprise nickel, manganese, and cobalt with a Ni:Mn:Co ratio 96:3:3.

[0097] The mounts of boric acid, sodium metasilicate, and sodium hexametaphosphate added to the reaction mixture to obtain each specific precursor is described below as grams of the corresponding reagent per 10 L of NiSCM solution.

[0098] Precursor-1 was obtained following the general precursor method, adding 0.45 grams of boric acid, 1.1 grams of sodium metasilicate, 0.4 grams of sodium hexametaphosphate.

[0099] Precursor-2 was obtained following the general precursor method, adding 0.9 grams of boric acid, 2.2 grams of sodium metasilicate, 0.85 grams of sodium hexametaphosphate.

[0100] Precursor-3 was obtained following the general precursor method, adding 1.35 grams of boric acid, 4.4 grams of sodium metasilicate, 1.7 grams of sodium hexametaphosphate.

[0101] Precursor-4 was obtained following the general precursor method, adding 0 grams of boric acid, 0 grams of sodium metasilicate, 0 grams of sodium hexametaphosphate.

[0102] Precursor-5 was obtained following the general precursor method, adding 0 grams of boric acid, 0 grams of sodium metasilicate, 1.7 grams of sodium hexametaphosphate.

[0103] Precursor-6 was obtained following the general precursor method, adding 0 grams of boric acid, 0 grams of sodium metasilicate, 6.6 grams of sodium hexametaphosphate.

[0104] Precursor-7 was obtained following the general precursor method, adding 0 grams of boric acid, 0 grams of sodium metasilicate, 13.2 grams of sodium hexametaphosphate.

[0105] Precursor-8 was obtained following the general precursor method, adding 0 grams of boric acid, 1.1 grams of sodium metasilicate, 0 grams of sodium hexametaphosphate.

[0106] Precursor-9 was obtained following the general precursor method, adding 0 grams of boric acid, 1.7 grams of sodium metasilicate, 0 grams of sodium hexametaphosphate.

[0107] Precursor-10 was obtained following the general precursor method, adding 0 grams of boric acid, 6.7 grams of sodium metasilicate, 0 grams of sodium hexametaphosphate.EXAMPLES

[0108] The present disclosure is further illustrated by the following examples. All examples and comparative examples have been obtained following the general method described below.General method to obtain a cathode active material according to this disclosure and comparative examples

[0109] A cathode active material is obtained through following steps:mixing the corresponding hydroxide metal-based precursor comprising Ni, Mn and Co, with LiOH and 0.125 mol% of ZrO? relative to Ni, Mn, and Co, to obtain a first mixture having a Li / (Ni, Mn, and Co) ratio of 0.96,heating the first mixture under oxygen atmosphere at 870 °C for 8 hours to obtain a first heated material,adding to the first heating material, 0.5 mol% of CoSO4 relative to Ni, Mn, and Co, and mixing to obtain a mixture A,subjecting the mixture A to wet ball milling to obtain a milled mixture comprising a solid phase and a liquid phase;separating the solid phase from the liquid phase by filtering and drying the solid phase, to obtain a solid-state intermediate;mixing the solid-state intermediate with LiOH, 0.125 mol% of ZrO? and 0.5 mol% of CO3O4, relative to Ni, Mn, and Co, to obtain a second mixture, wherein the Li / (Ni, Mn, and Co) ratio of the second mixture is about 1;heating the second mixture at 755 °C for 9 hours to obtain a second heated mixture; grinding and sieving the second heated mixture with AI2O3 to obtain a mixture B, wherein the amount of Al in the mixture B is 500 ppm relative to Ni, Mn, Co; mixing the mixture B with H3BO3 and WO3 to obtain a mixture C, wherein the amount of B is 500 ppm relative to Ni, Mn, Co, and the amount of W in the mixture C is 4500 ppm relative to Ni, Mn, Co;heating mixture C at 375 °C for 9 hours to obtain a heated mixture C; and grinding and sieving the heated mixture C with AI2O3, wherein the amount of Al is 500 ppm relative to Ni, Mn, Co, thereby obtaining a cathode active material.Example 1

[0110] Example 1 or EX 1 has been obtained following the general method using Precursor-1 as metal-based precursor.Example 2

[0111] Example 2 or EX 2 has been obtained following the general method using Precursor-2 as metal-based precursor.Example 3

[0112] Example 3 or EX 3 has been obtained following the general method using Precursor-3 as metal-based precursor.Comparative Example 1

[0113] Comparative Example 1 or CE 1 has been obtained following the general method using Precursor-4 as metal-based precursor.Comparative Example 2

[0114] Comparative Example 2 or CE 2 has been obtained following the general method using Precursor-5 as metal-based precursor.Comparative Example 3

[0115] Comparative Example 3 or CE 3 has been obtained following the general method using Precursor-6 as metal-based precursor.Comparative Example 4

[0116] Comparative Example 4 or CE 4 has been obtained following the general method using Precursor-7 as metal-based precursor.Comparative Example 5

[0117] Comparative Example 5 or CE 5 has been obtained following the general method using Precursor-8 as metal-based precursor.Comparative Example 6

[0118] Comparative Example 6 or CE 6 has been obtained following the general method using Precursor-9 as metal-based precursor.Comparative Example 7

[0119] Comparative Example 7 or CE 7 has been obtained following the general method using Precursor-10 as metal-based precursor.RESULTSTable II: P and Si mol % content relative to the total content of Ni, Mn, Co, Si and P, cell thickness increase, and recovered capacity of the examples and comparative examples.

[0120] According to the results present in Table II, a cathode active material comprising Si and P (Examples 1 to 3) show a lower cell thickness increase and a higher recovered capacity when compared to the corresponding cathode active material without P and Si (CE 1).

[0121] Additionally, Table II also indicates that only compositions comprising both P and Si, achieve the technical effects described above, see EX 1 and CE 2 to 7.

[0122] Therefore, a cathode active material according to the present disclosure might have an improved stability and capacity retention.

Claims

CLAIMS1. A cathode active material for lithium batteries, wherein the cathode active material comprises Li, M, and O, wherein M comprises:Ni in an atomic content x, wherein 0.60 < x < 0.98 relative to M;Mn in an atomic content y, wherein 0.005 < y < 0.30 relative to M;Co in an atomic content z, wherein 0.005 < z < 0.30 relative to M;P in an atomic content a, wherein 0.00001 < a < 0.07 relative to M;Si in an atomic content b, wherein 0.00005 < b < 0.01 relative to M;wherein x, y, z, a and b are determined by Inductively Coupled Plasma - Optical Emission Spectrometry, and wherein the Li / M atomic ratio is between 0.8 to 1.5.

2. A cathode active material according to claim 1, wherein 0.80 < x < 0.98 relative to M.

3. A cathode active material according to claim 1 or 2, wherein 0.01 < y < 0.15 relative to M.

4. A cathode active material according to any of the claims 1 to 3, wherein 0.01 < z < 0.15 relative to M.

5. A cathode active material according to any of the claims 1 to 4, wherein 0.00001 < a < 0.007 relative to M.

6. A cathode active material according to any of the claims 1 to 5, wherein 0.00005 < b < 0.005 relative to M.

7. A cathode active material according to any of the claims 1 to 6, wherein the Li / M atomic ratio is between 0.98 and 1.05.

8. A cathode active material according to any of the claims 1 to 7, wherein 0.80 < x < 0.98 relative to M; Mn in an atomic content y, wherein 0.01 < y < 0.10 relative to M; Co in an atomic content z, wherein 0.01 < z < 0.10 relative to M; P in an atomic content a, wherein 0.00008 < a < 0.002, Si in an atomic content b, wherein 0.00007 < b < 0.0005 relative to M, and wherein the Li / M atomic ratio is between 0.9 and 1.2, and wherein x+y+z+a + b = 1.

9. A method for manufacture a cathode active material according to any of the claims 1 to 8, wherein the method comprises the following steps:1) mixing a metal-based precursor with a first lithium source obtaining a first mixture;2) heating the first mixture at a temperature between 600 °C and 1000 °C to obtain a first heated mixture;3) mixing the first heated mixture with a second lithium source obtaining a second mixture; and4) heating the second mixture at a temperature between 400 °C and 1000 °C to obtain the cathode active material.

10. A method according to claim 9, wherein the first and / or second lithium source is LiOH, IJ2CO3 or a mixture thereof.

11. A method according to claim 9 or 10, wherein the first mixture is heated for a time between 5 and 12 hours.

12. A method according to any of the claims 9 or 11, wherein the second mixture is heated for a time between 3 and 12 hours.

13. A method according to any of the claims 9 to 12, further comprising the step of mixing the first heated mixture with 0.5 mol% of a cobalt source, relative to Ni, Mn and Co.

14. A battery comprising a cathode active material according to any of the claims 1 to 8.

15. The use of a battery according to claim 14 in an electrically powered device or system selected from the group consisting of: a portable computer, a tablet, a mobile phone, a telecommunication device, a power tool, mobile machinery, a robotic device, an energy storage system, an uninterruptible power supply system, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an extended-range electric vehicle, a fuel cell electric vehicle, a two-wheeler transportation system, a rail vehicle, a marine vessel, an aircraft, an aerospace system, a defense system, and a medical device.

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