CA2708708C - Negative electrode material for li-ion batteries - Google Patents
Negative electrode material for li-ion batteries Download PDFInfo
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
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- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
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- H01M4/00—Electrodes
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- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
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Abstract
The invention relates to lithium cells, accumulators or batteries and more particularly to an active material for the negative electrode of rechargeable batteries. The invention more particularly relates to a material that comprises a phase of the general formula Li2 +v-4c C c Ti3-w Fe x M y M'z O7-.alpha. in which M and M' are metal ions of groups 2 to 15 with an ionic radius of between 0.5 and 0.8 .ANG. in an oxygen octahedral environment, v, w, x, y, z and .alpha. being bonded by the relations 2.alpha. = -v+4w-3x-ny-n'z guaranteeing the electrical neutrality and n and n' being the respective formal oxidation degrees of M and M'; -0.5 <= v <= +0.5; y-z > 0; x+y+z = w and 0 < w <= 0.3; characterised in that at least a portion of the lithium is substituted by carbon according to the relation 0 < c <= (2+v)/4. The material has enhanced mass and volumetric capacities that can reach 190 Ah/kg while preserving the previously acquired advantages, including: a low capacity loss at the first cycle from 2 to 10 Ah/kg; excellent cyclability; and a low polarisation of 30 to 70 mV in C/15 mode.
Description
Negative Electrode Material For Li-Ion Batteries Technical Field The present invention relates to lithium cells, accumulators or batteries, and more particularly an active material for the negative electrode of rechargeable batteries.
Background of the Invention Batteries of Li-ion type are designed for new applications (portable electronics, cableless tools, hybrid vehicles) which require still more power and energy in order to respond to requirements. They should be stable over their life span while cycling and over long periods of time. Finally, they should respond to society's requirements associated with safety and protection of the environment.
Graphite is commonly used as the negative electrode for Li-ion batteries. It is considered however that lithium titanate oxide (ramsdellite, Li2Ti307) is a promising material, by virtue of its electrochemical performance associated with its low production cost and its non-toxicity.
Such a negative electrode material functions at a higher voltage than that of carbon (> 1V), ensuring in this way better functioning security. Moreover it is less subject to polarization, that is to say the potential difference between charge and discharge, than graphite and thus lends itself to a use requiring high power. The capacity of this material is however relatively low, reaching approximately 130 Ah/kg on a low regime (C/15) and 100 Ah/kg on a high regime (1 C) but has the advantage of having excellent reversibility during rapid regime cycling.
The capacity and current density of this Li2Ti307 have been first of all improved by substituting part of the Ti4+ by Fe3+. Then, and according to the teaching of EP-1 623 473, the reversible capacity at a low regime may now reach 140 Ah/kg, by virtue of a supplementary substitution by one or more of the following elements: Ti3+, Co2+, Co3+, Ni2+, Ni3+, Cu2+, Mg2+, Al3+, In3+, Sn4+, Sb3+, Sb5+. These substitutions also make it possible to reduce the synthesis temperature, which reduces production costs.
Summary of the Invention The present invention proposes above all to improve a substituted ramsdellite, so as to obtain improved specific capacity, while preserving the other properties of the existing poly-substituted product.
.=
Background of the Invention Batteries of Li-ion type are designed for new applications (portable electronics, cableless tools, hybrid vehicles) which require still more power and energy in order to respond to requirements. They should be stable over their life span while cycling and over long periods of time. Finally, they should respond to society's requirements associated with safety and protection of the environment.
Graphite is commonly used as the negative electrode for Li-ion batteries. It is considered however that lithium titanate oxide (ramsdellite, Li2Ti307) is a promising material, by virtue of its electrochemical performance associated with its low production cost and its non-toxicity.
Such a negative electrode material functions at a higher voltage than that of carbon (> 1V), ensuring in this way better functioning security. Moreover it is less subject to polarization, that is to say the potential difference between charge and discharge, than graphite and thus lends itself to a use requiring high power. The capacity of this material is however relatively low, reaching approximately 130 Ah/kg on a low regime (C/15) and 100 Ah/kg on a high regime (1 C) but has the advantage of having excellent reversibility during rapid regime cycling.
The capacity and current density of this Li2Ti307 have been first of all improved by substituting part of the Ti4+ by Fe3+. Then, and according to the teaching of EP-1 623 473, the reversible capacity at a low regime may now reach 140 Ah/kg, by virtue of a supplementary substitution by one or more of the following elements: Ti3+, Co2+, Co3+, Ni2+, Ni3+, Cu2+, Mg2+, Al3+, In3+, Sn4+, Sb3+, Sb5+. These substitutions also make it possible to reduce the synthesis temperature, which reduces production costs.
Summary of the Invention The present invention proposes above all to improve a substituted ramsdellite, so as to obtain improved specific capacity, while preserving the other properties of the existing poly-substituted product.
.=
The present invention relates more precisely to a negative electrode material that responds to the aforementioned requirements.
The invention relates to an active material for a lithium battery electrode, comprising a phase having a general formula Li2 +v_4cCcTi3-wFexMyMiz07_,, in which M and M' are metal ions of groups of 2 to 15 having an ionic radius between 0.5 and 0.8 A in an octahedral oxygen environment, v, w, x, y, z and a being associated by the relationships:
2 a = -v +4w-3x-ny-n'z, guaranteeing electroneutrality, with n and n' the respective formal degrees of oxidation of M and M'; -0.5 < v < +0.5; y + z> 0; x + y + z = w;
and 0 <w < 0.3;
characterized in that at least part of the lithium is substituted by carbon according to the relationship 0 <c < (2+v)/4.
The M and M ions may be selected from the list composed of Ti3+, Co2+, Co3+, Ni2+, Ni3+ Cu2+, Mg2+, Al3+, 1113+, Sn4+, Sb3+, et Sb5+. M is preferably Ni2+ and M' A13+.
The best results are obtained with x < 0.1; y < 0.2; and z < 0.1. Moreover, it is useful to choose x : y : z ratios within a range 1 : 3.9 to 4.1 : 0.90 to 1.10. It is more recommended to comply with c > 0.1, preferably c? 0.2.
Another object of the invention relates to a method for synthesizing the active material defined above, and comprises the steps of:
- reactive mixing and grinding of precursor compounds containing the elements Li, Ti, Fe, C, 0, M and M';
- synthesis of the ceramic phase by heating the mixture in an inert atmosphere at a temperature of 950 to 1050 C;
- rapid cooling of the ceramic phase.
It is self-evident that a person skilled in the art will be able to define the suitable quantities of the various reactants, so that the synthesized product corresponds to the general formula of the desired phase, as defined above.
= CA 02708708 2010-06-10 During this process it is useful for cooling of the ceramic phase to be carried out at at least 100 C/min, from the synthesis temperature up to no more than 400 C.
The invention also relates to the use of the active material defined above for the manufacture of lithium cells, accumulators or batteries.
The invention finally relates to lithium cells, accumulators or batteries containing the active material defined above.
The material of the invention has mass and volume capacities that may reach 190 Ah/kg, or 602 Al/m3, that is to say greater than those of the prior art, while preserving the prevously acquired advantages, notably:
- a small loss of capacity at the first cycle, of 2 to10 Ah/kg;
- excellent cyclability;
- low polarization of 30 to 70 mV in C/15 regime.
The ramsdellite structure consists of a network comprising Ti and Li ions in an octahedral oxygen environment and channels partly occupied by Li atoms in a tetrahedral environment. This arrangement leaves a large number of vacant tetrahedral sites in the channels and the Li/voids distribution may vary according to the synthesis conditions. Substitution metals occupy the octahedral sites of the network.
It is demonstrated here that carbon may be partially or totally substituted for lithium to lead to the formation of a modified ramsdellite, low in lithium. A certain number of insertion sites represented by the conventional notation 1:12+µ,.-v-(x+y+z)+3c correspond with the general formula Li2+v_4cCcTi3,FexMyM',07_,,. This modification favors the occupation of these sites, and on account of this improves the capacity of the original material. It is not however excluded for the synthesized material to be a composite, in particular for high values of the parameter c. The synthesized material therefore comprises a carbonaceous ramsdellite phase low in Li, and as the case may be also a non-carbonaceous ramsdellite enriched with Li.
The invention relates to an active material for a lithium battery electrode, comprising a phase having a general formula Li2 +v_4cCcTi3-wFexMyMiz07_,, in which M and M' are metal ions of groups of 2 to 15 having an ionic radius between 0.5 and 0.8 A in an octahedral oxygen environment, v, w, x, y, z and a being associated by the relationships:
2 a = -v +4w-3x-ny-n'z, guaranteeing electroneutrality, with n and n' the respective formal degrees of oxidation of M and M'; -0.5 < v < +0.5; y + z> 0; x + y + z = w;
and 0 <w < 0.3;
characterized in that at least part of the lithium is substituted by carbon according to the relationship 0 <c < (2+v)/4.
The M and M ions may be selected from the list composed of Ti3+, Co2+, Co3+, Ni2+, Ni3+ Cu2+, Mg2+, Al3+, 1113+, Sn4+, Sb3+, et Sb5+. M is preferably Ni2+ and M' A13+.
The best results are obtained with x < 0.1; y < 0.2; and z < 0.1. Moreover, it is useful to choose x : y : z ratios within a range 1 : 3.9 to 4.1 : 0.90 to 1.10. It is more recommended to comply with c > 0.1, preferably c? 0.2.
Another object of the invention relates to a method for synthesizing the active material defined above, and comprises the steps of:
- reactive mixing and grinding of precursor compounds containing the elements Li, Ti, Fe, C, 0, M and M';
- synthesis of the ceramic phase by heating the mixture in an inert atmosphere at a temperature of 950 to 1050 C;
- rapid cooling of the ceramic phase.
It is self-evident that a person skilled in the art will be able to define the suitable quantities of the various reactants, so that the synthesized product corresponds to the general formula of the desired phase, as defined above.
= CA 02708708 2010-06-10 During this process it is useful for cooling of the ceramic phase to be carried out at at least 100 C/min, from the synthesis temperature up to no more than 400 C.
The invention also relates to the use of the active material defined above for the manufacture of lithium cells, accumulators or batteries.
The invention finally relates to lithium cells, accumulators or batteries containing the active material defined above.
The material of the invention has mass and volume capacities that may reach 190 Ah/kg, or 602 Al/m3, that is to say greater than those of the prior art, while preserving the prevously acquired advantages, notably:
- a small loss of capacity at the first cycle, of 2 to10 Ah/kg;
- excellent cyclability;
- low polarization of 30 to 70 mV in C/15 regime.
The ramsdellite structure consists of a network comprising Ti and Li ions in an octahedral oxygen environment and channels partly occupied by Li atoms in a tetrahedral environment. This arrangement leaves a large number of vacant tetrahedral sites in the channels and the Li/voids distribution may vary according to the synthesis conditions. Substitution metals occupy the octahedral sites of the network.
It is demonstrated here that carbon may be partially or totally substituted for lithium to lead to the formation of a modified ramsdellite, low in lithium. A certain number of insertion sites represented by the conventional notation 1:12+µ,.-v-(x+y+z)+3c correspond with the general formula Li2+v_4cCcTi3,FexMyM',07_,,. This modification favors the occupation of these sites, and on account of this improves the capacity of the original material. It is not however excluded for the synthesized material to be a composite, in particular for high values of the parameter c. The synthesized material therefore comprises a carbonaceous ramsdellite phase low in Li, and as the case may be also a non-carbonaceous ramsdellite enriched with Li.
It should be noted that it is tetrahedral lithium that is substituted by carbon, constituting a C032 groupwhile being placed in the plane of 3 oxygens, the number of voids then being dependent on the values of v, x, y, z and c in the general formula above. For limiting values of substitutions of Li by C, the phase is emptied of structural lithium. It should be noted that any excess carbon will be deposited preferably at the grain boundaries and could improve the conductivity of the material.
The first step of the method according to the invention comprises a reactive mixture of compounds.
Solid precursors in the form of a fine powder are selected and mixed. This mixture preferably comprises the oxides of Ti and Fe, as well as those of the metals M and M'.
Other precursors are equally suitable, it being possible for these to be organic and/or inorganic compounds capable of forming Me-O-Me bonds (where Me is a metal) by condensation or hydrolysis/condensation.
Reference may be made, as an example, of oxides, carbonates, acetates, hydroxides, chlorides (e.g. AlC13), nitrates, Me-oxoalkoxides, this not being exhaustive and a person skilled in the art will know how to complete this. As regards lithium, this may be provided by another precursor, such as an oxide, hydroxide or chloride. Li2CO3 is however preferred.
The mixture will also include carbon or precursors of carbon that will be the most simple carbohydrate-containing phases, such as saccharides or derivatives of saccharides, for example glucose, fructose, sucrose, ascorbic acid, and polysaccharides corresponding to the condensation of saccharides, such as starch, cellulose and glycogen.
The proportion of each of the metals in the mixture of precursors corresponds to the stoichiometric proportion of the material in question, leading to the formation of the composite.
The proportion of carbon will be calculated taking account of losses of CO and CO2 by oxidation. This proportion it may be increased if an excess of carbon is desired at the grain boundaries.
The second step of the method according to the invention comprises heat treatment.
According to the invention, heat treatment is carried out in a controlled atmosphere (e.g. N2, Ar). It is carried out at a temperature that may lie between 980 C and 1050 C, preferably between 1 h 30 and 2h in order to obtain good crystallinity, connected with a limited particle size. The temperature rise to reach the reaction plateau may be carried out in a single rapid step since it makes it possible to minimize secondary reactions and the formation of undesirable titanates.
The last step consists of rapidly cooling the material.
The manufacturing process in its entirety is rapid and has reduced operating costs.
Description of the figures Figure 1: Scanning electron photomicrographs of the material Li2Ti307 substituted with Fe, Ni, Al without carbon (a) and with various carbon contents from 0.14 (b), 0.27 (c) and 0.68 (d) mole per mole of synthesized material.
Figure 2: Comparison of infrared spectroscopy bands between various materials substituted with Fe, Ni, Al synthesized without carbon (a) with various carbon contents, from 0.14 (b), 0.27 (c) and 0.68 (d) mole per mole of material synthesized.
Figure 3: Charge/discharge galvanostatic curves in C/15 regime of the material Li2Ti307 substituted with Fe, Ni, Al without carbon (a) and with 0.27 (b) mole of carbon per mole of synthesized material.
Figure 4: Specific capacities, in AK/kg of active material as a function of the quantity of carbon, in mole per mole of synthesized material, with C/15 and 1C regimes.
Detailed Description of Preferred Embodiments Comparative example 1 Example 1 concerns a ramsdellite Li2Ti307 substituted by three elements Fe, Ni, Al, without carbon according to the general formula Li2+v-4cCeTi3-wFexNiyA1,07_,E, where c = 0; v = -=
0.14; w = 0.15; x = 0.025; y = 0.1; and z = 0.025. Reactive grinding of the compounds Li2CO3 (0.7235 g), anatase TiO2 with a nanometric size (1.2028 g), Fe203 (0.021g), NiO (0.0393g) and finally A1203 (0.0134g) was carried out in a Pulverisette 7 (duration 15 min; speed 8) with agate balls and a ratio of the weight of balls/weight of product equal to 10.
Heat treatment was carried out in a boat under Ar in a single step. A ramp of 7 C/min was applied up to the synthesis temperature of 980 C, this temperature being maintained for 1 h 30. Cooling was carried out rapidly in argon so as to set the high temperature structure.
Examples 2 to 4 Examples 2 to 4 concern a ramsdellite Li2Ti307 substituted by three elements, Fe, Ni, Al, and by carbon, according to the general formula Li2 4-v-4cCcTi3_,,FeõNiyA1,07_õ, where v = -0.14; w =
0.15; x = 0.025; y = 0.1 and z = 0.025 and 0.1 <c <0.465. Sucrose was added as a carbon precursor, representing 5, 10 and 15 weight % based on the total weight weighed before synthesis. Refer to table 1 for the various carbon levels. Reactive grinding of the compounds Li2CO3, anatase TiO2 of nanometric size, Fe203, NiO, A1203 in stoichiometric quantities, was carried out in a Pulvérisette 7 (duration 15 min; speed 8) with agate balls and a ratio of the weight of balls/weight of product equal to 10. Heat treatment was carried out as in example 1.
Table 1: Summary of carbon levels in examples 1 to 4 Sucrose Total C Total C Substituted C
(%) (%) (mole/mole) (parameter c) before after synthesis after synthesis after synthesis synthesis Example 1 (*) 0 0 0 0 Example 2 5 0.63 0.14 0.14 Example 3 10 1.25 0.27 0.27 Example 4 15 2.95 0.68 0.465 (*) Comparative Figure 1 shows scanning electron photomicrographs of various synthesized examples. The base material without carbon according to example 1 shows (a) aggregates 10-20 jtm in diameter with a porous texture. By substituting the ramsdellite phase with various carbon levels according to examples 2 to 4, a change in morphology and texture was observed (b-d) creating an agglomerate of particles and filaments. With 0.68 mole of carbon, according to example 4, the remainder of presence of vibration bands between 1430 and 1500 cm-1 characteristic of the group C032-. This confirms substitution of carbon in the ramsdellite structure. The product prepared according to example 4 also shows (d) vibration bands towards 1650 cm-1. These correspond to conjugated C-C bands that belong to surface carbon.
Electrochemical tests were carried out in a half cell with two electrodes of which the negative was a metallic lithium washer. The positive comprised a mixture of 85% by weight of active material, 5% by weight of carbon black, and 10% by weight of PTFE binder. The electrolyte used was LiPF6 (1 M) in ethylene carbonate, dimethyl carbonate and propylene carbonate Figure 3 (a) shows charge and discharge curves (vs. Li) of the material without carbon, prepared according to example 1. Figure 3 (b) corresponds to the material with carbon, according to In figure 4, the values of specific capacities for the products prepared according to examples 1 and 4 are shown as a function of the quantity of carbon measured in the ramsdellite phase. With the two regimes, C/15 and C, the specific capacities increased with the presence of carbon. The capacity was no longer improved beyond the saturation point (c = 0.465, beyond which excess carbon was found on the surface of the material.
The first step of the method according to the invention comprises a reactive mixture of compounds.
Solid precursors in the form of a fine powder are selected and mixed. This mixture preferably comprises the oxides of Ti and Fe, as well as those of the metals M and M'.
Other precursors are equally suitable, it being possible for these to be organic and/or inorganic compounds capable of forming Me-O-Me bonds (where Me is a metal) by condensation or hydrolysis/condensation.
Reference may be made, as an example, of oxides, carbonates, acetates, hydroxides, chlorides (e.g. AlC13), nitrates, Me-oxoalkoxides, this not being exhaustive and a person skilled in the art will know how to complete this. As regards lithium, this may be provided by another precursor, such as an oxide, hydroxide or chloride. Li2CO3 is however preferred.
The mixture will also include carbon or precursors of carbon that will be the most simple carbohydrate-containing phases, such as saccharides or derivatives of saccharides, for example glucose, fructose, sucrose, ascorbic acid, and polysaccharides corresponding to the condensation of saccharides, such as starch, cellulose and glycogen.
The proportion of each of the metals in the mixture of precursors corresponds to the stoichiometric proportion of the material in question, leading to the formation of the composite.
The proportion of carbon will be calculated taking account of losses of CO and CO2 by oxidation. This proportion it may be increased if an excess of carbon is desired at the grain boundaries.
The second step of the method according to the invention comprises heat treatment.
According to the invention, heat treatment is carried out in a controlled atmosphere (e.g. N2, Ar). It is carried out at a temperature that may lie between 980 C and 1050 C, preferably between 1 h 30 and 2h in order to obtain good crystallinity, connected with a limited particle size. The temperature rise to reach the reaction plateau may be carried out in a single rapid step since it makes it possible to minimize secondary reactions and the formation of undesirable titanates.
The last step consists of rapidly cooling the material.
The manufacturing process in its entirety is rapid and has reduced operating costs.
Description of the figures Figure 1: Scanning electron photomicrographs of the material Li2Ti307 substituted with Fe, Ni, Al without carbon (a) and with various carbon contents from 0.14 (b), 0.27 (c) and 0.68 (d) mole per mole of synthesized material.
Figure 2: Comparison of infrared spectroscopy bands between various materials substituted with Fe, Ni, Al synthesized without carbon (a) with various carbon contents, from 0.14 (b), 0.27 (c) and 0.68 (d) mole per mole of material synthesized.
Figure 3: Charge/discharge galvanostatic curves in C/15 regime of the material Li2Ti307 substituted with Fe, Ni, Al without carbon (a) and with 0.27 (b) mole of carbon per mole of synthesized material.
Figure 4: Specific capacities, in AK/kg of active material as a function of the quantity of carbon, in mole per mole of synthesized material, with C/15 and 1C regimes.
Detailed Description of Preferred Embodiments Comparative example 1 Example 1 concerns a ramsdellite Li2Ti307 substituted by three elements Fe, Ni, Al, without carbon according to the general formula Li2+v-4cCeTi3-wFexNiyA1,07_,E, where c = 0; v = -=
0.14; w = 0.15; x = 0.025; y = 0.1; and z = 0.025. Reactive grinding of the compounds Li2CO3 (0.7235 g), anatase TiO2 with a nanometric size (1.2028 g), Fe203 (0.021g), NiO (0.0393g) and finally A1203 (0.0134g) was carried out in a Pulverisette 7 (duration 15 min; speed 8) with agate balls and a ratio of the weight of balls/weight of product equal to 10.
Heat treatment was carried out in a boat under Ar in a single step. A ramp of 7 C/min was applied up to the synthesis temperature of 980 C, this temperature being maintained for 1 h 30. Cooling was carried out rapidly in argon so as to set the high temperature structure.
Examples 2 to 4 Examples 2 to 4 concern a ramsdellite Li2Ti307 substituted by three elements, Fe, Ni, Al, and by carbon, according to the general formula Li2 4-v-4cCcTi3_,,FeõNiyA1,07_õ, where v = -0.14; w =
0.15; x = 0.025; y = 0.1 and z = 0.025 and 0.1 <c <0.465. Sucrose was added as a carbon precursor, representing 5, 10 and 15 weight % based on the total weight weighed before synthesis. Refer to table 1 for the various carbon levels. Reactive grinding of the compounds Li2CO3, anatase TiO2 of nanometric size, Fe203, NiO, A1203 in stoichiometric quantities, was carried out in a Pulvérisette 7 (duration 15 min; speed 8) with agate balls and a ratio of the weight of balls/weight of product equal to 10. Heat treatment was carried out as in example 1.
Table 1: Summary of carbon levels in examples 1 to 4 Sucrose Total C Total C Substituted C
(%) (%) (mole/mole) (parameter c) before after synthesis after synthesis after synthesis synthesis Example 1 (*) 0 0 0 0 Example 2 5 0.63 0.14 0.14 Example 3 10 1.25 0.27 0.27 Example 4 15 2.95 0.68 0.465 (*) Comparative Figure 1 shows scanning electron photomicrographs of various synthesized examples. The base material without carbon according to example 1 shows (a) aggregates 10-20 jtm in diameter with a porous texture. By substituting the ramsdellite phase with various carbon levels according to examples 2 to 4, a change in morphology and texture was observed (b-d) creating an agglomerate of particles and filaments. With 0.68 mole of carbon, according to example 4, the remainder of presence of vibration bands between 1430 and 1500 cm-1 characteristic of the group C032-. This confirms substitution of carbon in the ramsdellite structure. The product prepared according to example 4 also shows (d) vibration bands towards 1650 cm-1. These correspond to conjugated C-C bands that belong to surface carbon.
Electrochemical tests were carried out in a half cell with two electrodes of which the negative was a metallic lithium washer. The positive comprised a mixture of 85% by weight of active material, 5% by weight of carbon black, and 10% by weight of PTFE binder. The electrolyte used was LiPF6 (1 M) in ethylene carbonate, dimethyl carbonate and propylene carbonate Figure 3 (a) shows charge and discharge curves (vs. Li) of the material without carbon, prepared according to example 1. Figure 3 (b) corresponds to the material with carbon, according to In figure 4, the values of specific capacities for the products prepared according to examples 1 and 4 are shown as a function of the quantity of carbon measured in the ramsdellite phase. With the two regimes, C/15 and C, the specific capacities increased with the presence of carbon. The capacity was no longer improved beyond the saturation point (c = 0.465, beyond which excess carbon was found on the surface of the material.
Claims (12)
1. An active material for a lithium battery electrode, comprising a phase having a general formula Li2 +v-4c C c Ti3-w Fe x M y M'z O7-.alpha., in which M and M' are metal ions of groups of 2 to 15 having an ionic radius between 0.5 and 0.8 .ANG. in an octahedral oxygen environment, v, w, x, y, z and .alpha. being associated by the relationships:
2 .alpha. = -v +4w-3x-ny-n'z, with n and n' the respective formal degrees of oxidation of M and M';
-0.5 <= v <= +0.5;
y + z > 0;
x + y + z = w; and 0 < w <= 0.3;
characterized in that at least part of the lithium is substituted by carbon according to the relationship 0 < c <= (2+v)/4.
2 .alpha. = -v +4w-3x-ny-n'z, with n and n' the respective formal degrees of oxidation of M and M';
-0.5 <= v <= +0.5;
y + z > 0;
x + y + z = w; and 0 < w <= 0.3;
characterized in that at least part of the lithium is substituted by carbon according to the relationship 0 < c <= (2+v)/4.
2. The active material as claimed in claim 1, characterized in that M and M' are selected from the list composed of: Ti3+, Co2+, Co3+, Ni2+, Ni3+ Cu2+, Mg2+, Al3+, In3+, Sn4+, Sb3+ and Sb5+.
3. The active material as claimed in claim 1 or 2, characterized in that M
is Ni2+ and M' is Al3+.
is Ni2+ and M' is Al3+.
4. The active material as claimed in any one of claims 1 to 3, characterized in that x <= 0.1;
y <= 0.2; and z <= 0.1.
y <= 0.2; and z <= 0.1.
5. The active material as claimed in any one of claims 1 to 4, characterized in that the ratios x : y : z lie within a range of 1 : 3.9 to 4.1 : 0.90 to 1.10.
6. The active material as claimed in any one of claims 1 to 5, characterized in that c >= 0.1.
7. The active material as claimed in any one of claims 1 to 6, characterized by the presence of a phase substantially consisting of carbon.
8. A method for synthesizing the active material as claimed in any one of claims 1 to 7, comprising the steps of:
- reactive mixing and grinding of precursor compounds containing the elements Li, Ti, Fe, C, O, M and M';
- synthesis of the ceramic phase by heating the mixture in an inert atmosphere at a temperature of 980 to 1050°C, thereby obtaining a ceramic phase having the general formula Li2 +v-4c C cTi3-w Fe x M y M' z O 7-.alpha.;
- rapid cooling of the ceramic phase.
- reactive mixing and grinding of precursor compounds containing the elements Li, Ti, Fe, C, O, M and M';
- synthesis of the ceramic phase by heating the mixture in an inert atmosphere at a temperature of 980 to 1050°C, thereby obtaining a ceramic phase having the general formula Li2 +v-4c C cTi3-w Fe x M y M' z O 7-.alpha.;
- rapid cooling of the ceramic phase.
9. The method for synthesizing the active material as claimed in claim 8, characterized in that the rapid cooling of the ceramic phase to be carried out at at least 100°C/mM, from the synthesis temperature up to no more than 400°C.
10. Use for the manufacture of a lithium cell, accumulator or battery, of the active material as claimed in any one of claims 1 to 7.
11. A lithium cell, accumulator or battery containing the active material as claimed in any one of claims 1 to 7.
12. The active material as claimed in any one of claims 1 to 5, characterized in that c >= 0.2.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP07291475 | 2007-12-10 | ||
| EP07291475.7 | 2007-12-10 | ||
| US633008P | 2008-01-07 | 2008-01-07 | |
| US61/006.330 | 2008-01-07 | ||
| PCT/EP2008/009763 WO2009074208A2 (en) | 2007-12-10 | 2008-11-19 | Negative electrode material for li-ion batteries |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2708708A1 CA2708708A1 (en) | 2009-06-18 |
| CA2708708C true CA2708708C (en) | 2013-11-05 |
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ID=39885000
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2708708A Expired - Fee Related CA2708708C (en) | 2007-12-10 | 2008-11-19 | Negative electrode material for li-ion batteries |
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| Country | Link |
|---|---|
| US (1) | US8486309B2 (en) |
| EP (1) | EP2231524A2 (en) |
| JP (1) | JP5389046B2 (en) |
| KR (1) | KR101439586B1 (en) |
| CN (1) | CN101918317B (en) |
| BR (1) | BRPI0821589A2 (en) |
| CA (1) | CA2708708C (en) |
| TW (1) | TWI462378B (en) |
| WO (1) | WO2009074208A2 (en) |
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| KR101340821B1 (en) | 2009-03-30 | 2013-12-11 | 유미코르 | High voltage negative active material for a rechargeable lithium battery |
| JP2011165372A (en) * | 2010-02-05 | 2011-08-25 | Nippon Telegr & Teleph Corp <Ntt> | Negative electrode material for lithium secondary battery, method of manufacturing the same, and lithium secondary battery |
| US7909576B1 (en) * | 2010-06-24 | 2011-03-22 | General Electric Company | Fastening device for rotor blade component |
| JP5662261B2 (en) * | 2011-06-20 | 2015-01-28 | 日本電信電話株式会社 | Method for producing negative electrode material for lithium secondary battery and lithium secondary battery |
| DE102012203139A1 (en) * | 2012-02-29 | 2013-08-29 | Robert Bosch Gmbh | Solid cell |
| FR2992955A1 (en) | 2012-07-06 | 2014-01-10 | Saint Gobain Ct Recherches | MELT PRODUCT BASED ON LITHIUM |
| FR2992956A1 (en) | 2012-07-06 | 2014-01-10 | Saint Gobain Ct Recherches | MELT PRODUCT BASED ON LITHIUM |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPH11283624A (en) * | 1998-03-31 | 1999-10-15 | Matsushita Electric Ind Co Ltd | Lithium secondary battery and method of manufacturing the same |
| JP2001185141A (en) * | 1999-12-22 | 2001-07-06 | Kyocera Corp | Lithium battery |
| JP2002008658A (en) * | 2000-06-27 | 2002-01-11 | Toyota Central Res & Dev Lab Inc | Lithium-titanium composite oxide for electrode active material of lithium secondary battery and method for producing the same |
| CA2327370A1 (en) * | 2000-12-05 | 2002-06-05 | Hydro-Quebec | New method of manufacturing pure li4ti5o12 from the ternary compound tix-liy-carbon: effect of carbon on the synthesis and conductivity of the electrode |
| EP1261050A1 (en) * | 2001-05-23 | 2002-11-27 | n.v. Umicore s.a. | Lithium transition-metal phosphate powder for rechargeable batteries |
| ES2336200T3 (en) * | 2001-10-02 | 2010-04-09 | Valence Technology, Inc. | LITHIUM BATTERY BASED ON TITANATES OF LITIATED TRANSITION METALS. |
| CN100448071C (en) * | 2003-03-18 | 2008-12-31 | 黄穗阳 | Lithium battery positive electrode material and preparation method thereof |
| DE602004001349T2 (en) * | 2003-05-09 | 2007-05-10 | Umicore | NEGATIVE ELECTRODE FOR LITHIUM BATTERIES |
-
2008
- 2008-11-19 CA CA2708708A patent/CA2708708C/en not_active Expired - Fee Related
- 2008-11-19 KR KR1020107013399A patent/KR101439586B1/en not_active Expired - Fee Related
- 2008-11-19 US US12/746,319 patent/US8486309B2/en not_active Expired - Fee Related
- 2008-11-19 BR BRPI0821589A patent/BRPI0821589A2/en not_active IP Right Cessation
- 2008-11-19 CN CN2008801200794A patent/CN101918317B/en not_active Expired - Fee Related
- 2008-11-19 EP EP08859157A patent/EP2231524A2/en not_active Withdrawn
- 2008-11-19 WO PCT/EP2008/009763 patent/WO2009074208A2/en not_active Ceased
- 2008-11-19 JP JP2010537271A patent/JP5389046B2/en not_active Expired - Fee Related
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| Publication number | Publication date |
|---|---|
| CN101918317B (en) | 2013-03-27 |
| KR101439586B1 (en) | 2014-09-11 |
| KR20100113488A (en) | 2010-10-21 |
| EP2231524A2 (en) | 2010-09-29 |
| TWI462378B (en) | 2014-11-21 |
| JP2011507166A (en) | 2011-03-03 |
| TW200941801A (en) | 2009-10-01 |
| CA2708708A1 (en) | 2009-06-18 |
| US20110042628A1 (en) | 2011-02-24 |
| CN101918317A (en) | 2010-12-15 |
| WO2009074208A3 (en) | 2009-09-17 |
| BRPI0821589A2 (en) | 2015-09-29 |
| WO2009074208A2 (en) | 2009-06-18 |
| JP5389046B2 (en) | 2014-01-15 |
| US8486309B2 (en) | 2013-07-16 |
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