CN1454184A

CN1454184A - Vanadium oxide hydrate compositions

Info

Publication number: CN1454184A
Application number: CN00819943A
Authority: CN
Inventors: C·托拉迪
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 2000-10-07
Filing date: 2000-10-07
Publication date: 2003-11-05
Also published as: EP1337468A1; JP2004511407A; AU2000279975A1; WO2002030824A1; WO2002030824A9; KR20030059177A

Abstract

Disclosed herein are new vanadium oxide hydrate compositions highly suitable for use as electrode-active materials in primary and secondary lithium and lithium ion batteries, and a process for their preparation.

Description

Vanadium oxide hydrate composition

Technical Field

The present invention relates to novel vanadium oxide hydrate compositions and methods for their preparation that are particularly suitable for use as electrode active materials in lithium and lithium ion primary and secondary batteries.

Background

As already known in the art, the general formula V is used₂O₅.nH₂Vanadium oxide hydrates, denoted by O, have generally never been shown to have the properties required for practical use in rechargeable or "storage" lithium batteries, while having high lithium ion insertion capacity, low hysteresis in charge/discharge cycles, high power density and low sensitivity to discharge rate.

Le, etcHuman, U.S. Pat. No. 5,674,642 discloses a fibrous V₂O₅.nH₂O compositions having a lithium insertion capacity high enough to be selected as an electrode active material in a lithium battery. Fibers and ribbons made by methods similar to Le et al are also disclosed in s.passerini et al, electro chemica Acta, volume 44, 1999, pp.2209-2217, and j.livage, chem.mater. (chemicals), volume 3, 1991, pp.578-593.

It is known in the art to combine an electrode active material with a binder resin and carbon black to form an electrode paste or ink for use in the battery art. Carbon black greatly enhances the performance of the electrode material, enabling it to reach much higher percentages relative to its theoretical capacity at high charge/discharge rates. Although Le et al disclose such compositions in the above literature, their capacity and reversibility still suffer considerable losses at high charge/discharge rates; the problem will become more severe at higher rates.

Further improvement of the capacity towards the theoretical limit at high charge/discharge rates can be achieved by using higher carbon black and V at constant binder loading₂O₅.nH₂The ratio between O is achieved by forming the electrodes, but there are practical limits to this ratio. If the amount of carbon black is increased without also increasing the binder, this results in a loss of mechanical integrity of the finished electrode layer. And the addition of the binder dilutes the electrode active material, so that the energy density of the fabricated battery is seriously lowered.

Le et al also disclose V₂O₅.nH₂O with 4-7 wt% chemically bonded carbon solvent residue, which provides an improvement in electrochemical potential to the cell but maintains only the capacity and reversibility attributes of the precursor composition.

Le et al describe a manufacturing V₂O₅.nH₂O gelling process, which is complicated and slowSlow and expensive. In textbook "advanced inorganic chemistry" (fourth edition, j.wiley&Sons corporation, 1980, p.711), Cotton and Wilkinson, describe a method, packageComprises the following steps: precipitation of a brick-red form of V by addition of a mineral acid to an aqueous vanadate solution₂O₅. This process is also used in EP747123a2, but the products produced are said to be of low yield and high impurities content, and the performance fluctuations are large. Similar methods have been used by Theobald, and the results are almost equally poor in "Bulletin de la Societe Chimique de France" 1975, 7-8, pp.1607-1612.

Summary of The Invention

The invention provides a method for producing MxV₂O₅Ay.nH₂O, wherein M is selected from NH₄ ⁺、Na⁺、K⁺、Rb⁺、Cs⁺And Li⁺(ii) a A is selected from NO₃ ^-、SO₄ ^-2And Cl^-(ii) a X is more than 0 and less than 0.7, and y is more than 0 and less than 0.7; and 0.1 < n < 2, the method comprising,

mixing water-soluble vanadate with water to form a solution; and

adding a strong mineral acid into the solution so that the molar ratio of acid protons to vanadium is between 0.70: 1 and 6: 1.

In addition, the present invention provides a composition comprising non-fibrous MxV₂O₅Ay.nH₂O, wherein M is selected from NH₄ ⁺、Na⁺、K⁺、Rb⁺、Cs⁺And Li⁺(ii) a A is selected from NO₃ ^-、SO₄ ^-2And Cl^-(ii) a X is more than 0 and less than 0.7, and y is more than 0 and less than 0.7; and 0.1 < n < 2, the method comprising 0.1 < n < 2.0, the electrode active material composition being characterized in that its initial discharge capacity is equal to 315 to 400mAh/g of electrode active material composition.

Also provided is an electrode composition comprising the electrode active material composition of the present invention.

Finally, an electrochemical cell (electrochemical cell) is provided which comprises an electrode composition comprising the electrode active material composition of the present invention.

Drawings

FIG. 1 is a graph showing the initial discharge capacity as a function of the H/V ratio measured in examples 1 to 16.

FIGS. 2a and 2b show scanning electron microscope micrographs of example 10 non-fibrous product at 10,000 and 30,000 magnifications, respectively.

FIGS. 3a and 3b present scanning electron microscope micrographs of example 16 non-fibrous product at 10,000 and 30,000 magnifications, respectively.

Fig. 4 and 5 depict an initial discharge curve and a first recharge curve, representing milliamp hours per gram of electrode active material as a function of voltage, as determined in examples 10 and 16, respectively.

Detailed Description

The invention relates to a method for forming a high-purity non-fibrous form V₂O₅.nH₂O, wherein 0.1 < n < 2, which is particularly suitable for use as an electrode active material in batteries, particularly lithium and lithium ion primary and secondary batteries, and to compositions, electrodes and chemical cells made therefrom. It was found in the practice of the process of the invention that the V so formed₂O₅.nH₂O generally exhibits a degree of impurity, both residual cations from the vanadate and residual anions from the strong acid used in the process of the invention. These residues do not affect the invention V₂O₅.nH₂Suitability of O for its intended use.

Since the impurities are chemically incorporated into the product, the product of the process is more appropriately represented by the following formula: MxV₂O₅Ay.nH₂O, wherein M is selected from NH₄ ⁺、Na⁺、K⁺、Rb⁺、Cs⁺And Li⁺(ii) a A is selected from NO₃ ^-、SO₄ ^-2And Cl^-(ii) a X is more than 0 and less than 0.7, and y is more than 0 and less than 0.7; and n is more than 0.1 and less than 2. Preferably, x and y are as close to 0 as possible, but in practice they are usually about 0.2.

For clarity of explanation and ease of use in the present invention, the term "V" is used₂O₅.nH₂O "will be used as a shorthand to refer to the product of the process of the present invention, which covers the entire range of x and y numerical values, i.e., from 0 to 0.7.

In the process according to the invention, the water-soluble vanadate is dissolved in water, preferably with heating, and the desired product V is subsequently obtained₂O₅.nH₂O precipitates in high yield. The resulting product exhibits a non-fibrous morphology characterized by a surprisingly high initial discharge capacity in standard lithium battery test cells and very high reversibility.

For the purposes of the present invention, the term "initial discharge capacity" refers to the discharge capacity of a standard lithium metal battery in which the invention V is incorporated as an electrode active cathode material₂O₅.nH₂And (3) O composition. The "initial discharge capacity" measured in the standardized configuration is believed to be the V of the invention₂O₅.nH₂Relative indication of the intrinsic lithium ion insertion capacity of the O composition. For the purposes of the present invention, the initial discharge capacity is determined by: v of the invention₂O₅.nH₂O is combined with carbon black and a binder resin as in the various embodiments described below to form an electrode ink or paste. The electrode ink or paste so formed was incorporated into a standard lithium metal button cell structure as described below. The button cell so formed is in a charged state. Subsequently, the cell is discharged in the range of 4-1.5V, during which the voltage (V) and current (I) are measured as a function of time. The initial discharge capacity was measured under a constant current discharge of 0.5mA at the initial stage. When the voltage reaches 1.5V, the discharge mode changes to a constant voltage, during which the voltage remains constant and the current slowly decays to 1/10 mA, i.e. 0.05mA, of the original value. The constant voltage discharge portion has the effect of reducing the potential drop due to current flow by allowing the cell to reach almost equilibrium, so that the remaining cell polarization is essentially due to insertion of lithium into the cathode materialCaused by the overvoltage. The initial discharge capacity is a constant current andintegrated charge transfer amount during constant voltage discharge portion. To perform such a determination, it has been found desirable to employ a Maccor series 4000 tester (Maccor corporation, Tulsa, Oklahoma) employing a 10mA maximum current capacity channel and version 3.0 software (SP 1).

In the process according to the invention, water, preferably deionized water, is mixed with vanadate, and the mixture thus formed is preferably heated, preferably with stirring, to a temperature in the range from 80 ℃ up to and including the boiling point of the mixture, so as to form a solution having a vanadium concentration of 0.01 to 3M, preferably 0.1 to 1M. Suitable vanadate solutions include ammonium, alkali and alkaline earth vanadate salts, e.g., NH₄VO₃、LiVO₃、NaVO₃、KVO₃、RbVO₃、CsVO₃And MgV₂O₆. Preferably NH₄VO₃、LiVO₃、KVO₃、MgV₂O₆. Most preferably NH₄VO₃、LiVO₃And MgV₂O₆. Or, V₂O₅It is also possible to mix the aqueous ammonium, alkali metal or alkaline earth metal hydroxide in a stoichiometric amount to form the corresponding vanadate solution in situ. Most preferably, the solution is heated to its boiling point.

To the preferably heated, most preferably boiling, solution so prepared, a strong mineral acid is added to provide a ratio of acid protons to vanadium (hereinafter "H/V ratio") in the range of about 0.70: 1 to 6: 1. Acids suitable for the practice of the present invention include sulfuric acid, nitric acid, hydrochloric acid, or other strong acids, except for phosphorus-containing acids, since it will undesirably form vanadium phosphate byproducts. In addition, in NH₄And Rb and possibly Na, K and Cs, the acid/vanadium ratio must be sufficiently high, typically at least 1: 1, to avoid and greatly reduce M₂V₆O₁₆Co-generation of (1). The acid may be incorporated in concentrated or diluted form, preferably in dilute solution form for safety.

After addition of the acid, mixing, preferably with heating to a temperature of at least 80 ℃, most preferably to the boiling point, should last for at least 1min, but may last for several hours. In general terms, the amount of the solvent to be used,mixing for 5-60 min will be sufficient. Generated V₂O₅.nH₂The O precipitate may be recovered by any convenient method, including decanting the supernatant after precipitation, filtering, centrifuging, and the like. The precipitate is characterized by a non-fibrous morphology and a trash content of less than about 15%, typically less than about 4%.

Dissolution of vanadate in water can in most cases be accomplished at any convenient temperature, including at room temperature, but in the practice of the invention it has been found that the rate of dissolution is rather slow at room temperature, while heating can be greatly accelerated, especially to and near boiling temperatures. At temperatures below the boiling point, dissolution can be greatly accelerated by stirring.

Invention V₂O₅.nH₂Precipitation of O by addition of an acid to the vanadate solution may be accomplished at any convenient temperature, including at room temperature. However, it has been found highly desirable in the practice of the present invention that the reaction be carried out at elevated temperatures, particularly in the range of 80 ℃ to the boiling point of the solution.Most preferably, the reaction is carried out at the boiling point. In the practice of the present invention, it has been found that when the reaction temperature is less than 80 ℃, it is highly likely that the yield will be reduced, the quality of the reaction product will be lowered and the properties will be deteriorated.

Although not strictly necessary, it is highly preferred that the recovered solids, regardless of the manner in which they are collected, be reslurried with fresh water to remove impurities, and then the solids be recovered again. The number of washing steps required to achieve the desired level of purity will depend on the solubility of the impurities, the amount of water used, the desired level of purity, and the efficiency of the slurry formulation process. In the practice of the present invention, it has been found that for many purposes, it is sufficient that the washing be continued until the supernatant pH reaches about pH 2 or higher.

The recovered solids are then dried by any convenient means, including but not limited to radiant heating and oven drying. After drying, crushing and sieving, the V thus prepared₂O₅.nH₂O may be incorporated into the electrode composition.

The precipitate obtained is in the form of a non-fibrous form V having a high initial discharge capacity₂O₅.nH₂And O. The percentage of precipitated dissolved vanadium, the main factor determining the single pass yield, depends mainly on the H/V ratio, with the highest yields being achieved at H/V ratios equal to about 1: 1 to 2: 1. By "non-fibrous" is meant having no microstructure consisting of fibers or ribbons, as revealed by scanning electron microscopy at 30,000 magnification. FIGS. 2a and 2b present scanning electron micrographs at 10,000 and 30,000 magnifications, respectively, of the sample of example 10 herein; figures 3a and 3b represent similar micrographs of the carbon coated sample of example 16 herein.

Non-fibrous V prepared according to the process of the invention₂O₅.nH₂O is characterized by a ratio of V outside the limits of the H/V ratio of the process according to the invention, prepared by precipitation of vanadium with hydrochloric acid₂O₅.nH₂O significantly high initial discharge capacity. This is shown in FIG. 1, where the initial discharge capacity from the specific embodiment exemplified below is shown as a function of the H/V ratio. Of particular note is the rapid increase and decrease in initial discharge capacity at the lower upper limit of the range of H/V ratios suitable for practicing the present invention. The optimum H/V ratio is achieved at an H/V ratio equal to about 1.5: 1 to 2.5: 1.

Falling outside the preferred H/V ratio range, the product will begin to deteriorate, the yield will begin to decrease, the impurity content increases, and the initial discharge capacity decreases. Exceeding a ratio of H/V6 of 0.70 will result in such less desirable characteristics.

Invention V₂O₅.nH₂O provides a high degree of reversibility to standard lithium test cells described herein. A proportion of up to 99% of the available capacity can be recovered by recharging. As illustrated in FIGS. 4 and 5, which give the discharges described below in connection with examples 10 and 16, each charge is followed by a charge cycle representing the inverse of the discharge cycleAnd (4) period. As can be seen from the figure, low polarization occurs. Examples 10 and 16 represent the same synthesis except that example 16 includes a coated carbon composition and example 10 does not. Polarization of the coated carbon sample is less than V₂O₅.nH₂O is not coated on carbon, e.g. closerThe low pressure area of the curve is indicated. The beneficial effects of the coated carbon composition become more pronounced as the charge/discharge rate increases.

Cycle life is defined as the number of cycles of charge/discharge cycling that the test button cell can withstand before the discharge capacity drops to 80% of its initial value. The inventors believe that the cycle life reaches an optimum value at an H/V ratio equal to about 4. That is, there appears to be a certain balance between yield on the one hand and initial discharge capacity, and on the other hand cycle life.

It has also been found in the practice of the present invention that the initial discharge capacity is dependent on the cation of the vanadium salt used in the process of the present invention. The highest initial discharge capacity is at V₂O₅.nH₂O is replaced by NH₄VO₃、LiVO₃Or MgV₂O₆Achieved at the time of generation.

Those skilled in the art will appreciate that the present invention V₂O₅.nH₂The requirements for a given application will allow different tradeoffs between the several process variables described to obtain the product best suited for that application.

In a preferred embodiment of the process of the invention, for example, elemental carbon, such as carbon black, is slurried into the vanadium salt solution prior to the addition of acid. In the practice of the invention, the carbon black may be added to the water prior to dissolution of the vanadium salt therein, either simultaneously with or after dissolution of the vanadium salt. The precipitated product produced after the addition of acid in the manner described above is a finely divided powder of carbon black coated with V₂O₅.nH₂O, which is highly preferred for use in lithium batteries or rechargeable batteries. The coated carbon black product exhibits V₂O₅.nH₂O's characteristic high initial discharge capacity, low polarization, high capacity retention at high charge rates and high vanadium utilization or energy efficiency. It has been found that carbon black suitable for the practice of the present invention is used in an amount of 1 to 12%, preferably 4 to 8% by weight, based on the final carbon-V isolated₂O₅.nH₂The total weight of the dry powder is taken as a reference. 1 to 12 wt% corresponding to a carbon-vanadium molar ratio of about 0.1 to 1.2, when n is approximatelyEqual to 1.2, is a preferred value.

Any form of finely divided elemental carbon is suitable for the practice of the present invention. Super P carbon black, commercially available from MMMS. A. carbon company (Brussel, Belgium), is one of the suitable elemental carbons and has a surface area of about 62m²(ii) in terms of/g. Although there is no particular limitation on the surface area of the carbon black suitable for use in the present invention, it is believed that higher surface areas are preferred over lower surface areas. In one embodiment, the carbon black is first slurried separately in an aqueous dispersion and the resulting slurry is then added to a heated vanadate solution.

The process of the present invention can be carried out either in batch or continuous mode. A continuous process with a circulating stream of undeposited vanadate is particularly desirable when the reaction is operated at relatively low yields.

The process of the present invention preferably reduces the values of x and y to approximately zero as much as possible and removes any other residual ionic impurities such as adsorbed protons. This was achieved by washing the precipitate thoroughly with water and filtering.

As is well known in the art of chemical cell manufacture, the shaping of the electrode composition involves the application of an electrode active material such as V of the present invention₂O₅.nH₂O, mixed with carbon black and binder resin, thereby providing the electrode composition with improved electronic conductivity and excellent physical integrity. However, in practice it has been found that 8 wt% carbon black represents a typical practical maximum carbon black concentration, as levels in excess of 8% often result in the electrode composition becoming undesirably difficult to process and brittle. The present invention solves the problem of incorporating additional amounts of elemental carbon into the composition with minimal negative impact on the physical integrity of the electrode compositions made therefrom. For example, a preferred electrode composition of the invention comprises a V incorporating 8% carbon black made according to the process of the invention as described above₂O₅.nH₂An O-coated carbon black composition. Such compositions can be mixed with additional 8% carbon black and binder resin according to prior art methods, resulting in a tough, formable electrode compositionContaining 16% carbon black and improved electrochemical performance as would be expected from this higher total carbon black concentration in the electrode composition.

Suitable binder resins include EPDM rubber, polyvinylidene fluoride and copolymers thereof with, for example, hexafluoropropylene, as well as other resins such as are known in the art to be suitable for this purpose. The binder resin is typically first dissolved in a volatile solvent and then combined with the other electrode components. Suitable solvents are well known in the art and include, inter alia, acetone, cyclohexane and cyclopentanone. Not all binders suitable for the practice of the present invention require dissolution in a solvent.

Found in the practice of the invention and comprise the invention V₂O₅.nH₂O but the V₂O₅.nH₂O is not coated on elemental carbon, and comprises coating with V₂O₅.nH₂The electrode compositions of the present invention of the elemental carbon of O exhibit considerable benefits. These benefits include a reduction in polarization upon charge/discharge cycling, an increase in the initial discharge capacity per gram of vanadium, and a significant reduction in the tendency of the initial discharge capacity to decrease as the discharge rate increases.

Production of V by the invention₂O₅.nH₂The method of O-coating carbon can also be used to add or dope other elements. For example, if the addition of acid precipitates V₂O₅.nH₂Addition of a transition metal or metal compound before O gives a chemically modified precipitated product having the general formula M_xB_zV₂O₅A_y.H₂O, wherein M is the product from which the V of the invention precipitates₂O₅.nH₂A cation derived from a vanadate parent to O, wherein x is 0.0 to 0.7, A is an anion derived from an acid, y is 0.0 to 0.7, and BIs a transition, main group or rare earth metal, z is 0.0 to 1.0 and n is 0.1 to 2.0.

The invention will be further described in the following specific embodiments. Those skilled in the art will appreciate that the invention is capable of numerous modifications, substitutions and rearrangements without departing from the spirit and essential attributes thereof.

Most of the specific embodiments given below relate to the formation of a standard chemical battery in which the electrode composition of this embodiment is used as the cathode as opposed to a lithium metal anode. Lithium ion batteries can also be formed according to the methods of the present invention and are preferred for many applications.

Lithium ion batteries can be assembled in a charged state using anode materials that already contain suitable recyclable lithium or portions thereof. This can be achieved in a manner known in the art, for example, by contacting lithium metal or other lithium source with the carbon-based anode material during cell assembly, which will allow the desired recyclable lithium to be incorporated into the carbon structure. Another means of employing the materials of the present invention in a lithium ion battery would include deliberately prelithiating the vanadium oxide hydrate, for example either by chemical means or by electrochemical means. This will increase the lithium content in the material of the invention to a desirably high level for use in a lithium ion battery having an initially discharged anode. An example of a lithium ion battery is given in example 17.

Examples of the invention	H+/V Ratio of	Li Discharge capacity (mAh/g)	Raw materials MVO₂	The acid used is	％ Yield of	H₂O (mL)	Temperature of (B/℃)	Time of day (min)	Thickness of electrode (μm)
Examples of the invention	H+/V Ratio of	Li Discharge capacity (mAh/g)	Raw materials MVO₂	The acid used is	％ Yield of	H₂O (mL)	Temperature of (B/℃)	Time of day (min)	Thickness of electrode (μm)	1	0.7	315	LiVO₃ 18.2g	HNO₃	42	450	B	5	115
2	0.75	264	V₂O₅ 15.6g LiOH.H₂O 7.2g	H₂SO₄	65	900	B	35	108	1	0.7	315	LiVO₃ 18.2g	HNO₃	42	450	B	5	115
2	0.75	264	V₂O₅ 15.6g LiOH.H₂O 7.2g	H₂SO₄	65	900	B	35	108	3	1	355	LiVO₃ 18.2g	H₂SO₄	97	900	B	15	115
4	1.1	378	V₂O₅ 50g LiOH.H₂O 23.1g	HCl	-	350	80℃	15	90	3	1	355	LiVO₃ 18.2g	H₂SO₄	97	900	B	15	115
4	1.1	378	V₂O₅ 50g LiOH.H₂O 23.1g	HCl	-	350	80℃	15	90	5	1.4	367	NH₄VO₃ 20.1g	HNO₃	88	450	B	5	125
6	1.4	340	LiVO₃ 18.2g	HNO₃	89	450	B	10	110	5	1.4	367	NH₄VO₃ 20.1g	HNO₃	88	450	B	5	125
6	1.4	340	LiVO₃ 18.2g	HNO₃	89	450	B	10	110	7	1.4	370	NH₄VO₃ 20.1g	HNO₃	91	900	B	20	130
8	1.5	383	NH₄VO₃ 8.2g	HNO₃	-	150	B	2	120	7	1.4	370	NH₄VO₃ 20.1g	HNO₃	91	900	B	20	130
8	1.5	383	NH₄VO₃ 8.2g	HNO₃	-	150	B	2	120	9	2	365	MgV₂O₆ 18.3g	H₂SO₄	96	900	B	15	123
10	2	370	NH₄VO₃ 20.1g	H₂SO₄	92	900	B	20	130	9	2	365	MgV₂O₆ 18.3g	H₂SO₄	96	900	B	15	123
10	2	370	NH₄VO₃ 20.1g	H₂SO₄	92	900	B	20	130	11	2	374	NH₄VO₃ 20.1g	H₂SO₄	89	900	B	60	125
12	2.8	350	NH₄VO₃ 20.1g	HNO₃	73	900	B	20	115	11	2	374	NH₄VO₃ 20.1g	H₂SO₄	89	900	B	60	125
12	2.8	350	NH₄VO₃ 20.1g	HNO₃	73	900	B	20	115	13	4	325	NH₄VO₃ 20.1g	H₂SO₄	76	900	B	20	115
14	4	321	LiVO₃ 18.2g	H₂SO₄	62	900	B	20	98	13	4	325	NH₄VO₃ 20.1g	H₂SO₄	76	900	B	20	115
14	4	321	LiVO₃ 18.2g	H₂SO₄	62	900	B	20	98	15	6	272	NH₄VO₃ 20.1g	H₂SO₄	55	900	B	20	105

Examples

In examples 1-16 below, a vanadium oxide hydrate is formed which is then combined with other materials, such as those known in the art, to form an electrode for subsequent incorporation into a lithium battery, all according to the methods described below. Is measured byLithium discharge capacity of the button cell in shape, results are given to the invention V₂O₅.nH₂The ratio of vanadium to acid used in the O formation is plotted as shown in fig. 1.

Example 1

In a 1L Pyrex beaker, 18.2g LiVO₃Added to about 450mL of deionized water with stirring with a magnetic stirrer coated with polytetrafluoroethylene. The contents of the beaker are heated to boiling point, resulting in a solution. 7.5mL of concentrated nitric acid was added to the boiling solution with stirring. The resulting solution was boiled for an additional 5min with stirring. The H/V ratio was 0.7.

Subsequently, the beaker was removed from the heater and stirring was continued at room temperature for 3.5 h. The unwashed gelatinous precipitate was collected on filter paper by suction filtration. The product was filtered very slowly and the filtrate was orange indicating the presence of a significant amount of un-precipitated vanadium. The pH of the filtrate was measured using multi-color pH paper and was about 3. The filter cake was dried overnight under an infrared heating lamp to yield 7.4g of material. The composition (Li) is converted from chemical and thermogravimetric analysis_0.07V₂O₅(NO₃)_0.070.9H₂And O. From this composition, the product yield was calculated to be 42%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

After grinding to a powder, the powder was sieved through a 200 mesh screen to obtain a powder suitable for the manufacture of cathodes. To make an electrode, 1.5000g of the powder was combined with 0.1364g of Super P carbon black commercially available from MMM S.A. carbon (Brussel, Belgium) and 1.705g of a 4 wt% solution of EPDM rubber in cyclohexane. 2.5mL of additional cyclohexane was added to improve flow. The mixture was shaken in a mechanical shaker for 15min in a glass vial with a lid, resulting in the formation of a cathode paste.

Spreading the cathode paste to Teflon^®FEP (DuPont, Wilmington DE) and was drawn into a film using a 15 mil gap doctor blade. Dried film consisting of 88% by weight of powder, 4% by weight of binder and 8% by weight of carbon black, passed through calendering rolls in a Kapton^®Polyimide sheets (dupont) were thermoformed between sheets at 2000psi and 110 c to form a dense electrode sheet suitable for use as a cathode in a lithium battery. The sheet thickness was 115 μm.

The resulting compact electrode sheet is used in an electrochemical cell as a cathode as opposed to a lithium metal anode. LiPF₆Dissolved in EC/DMC (ethylene carbonate/dimethyl carbonate) was used as an electrolyte solution. A glass fiber separator was used between the two electrodes. Disks of cathode, anode and separator were die cut. The cathode and separator sheets were soaked in the electrolyte solution in a dry nitrogen atmosphere and then stacked with the lithium sheets into button cell disks and packaged under pressure using a 2325 button cell clamping machine system (manufactured by National research council, canada). The button cell was tested as described above and the initial discharge capacity was found to be 315 mAh/g.

Example 2

15.6g of Anhydrous V₂O₅And 7.2g LiOH₂O was mixed with 900mL of deionized water and treated as in example 1, resulting in V₂O₅.nH₂O, except that dilute sulfuric acid prepared by mixing 3.6mL of concentrated sulfuric acid with 40mL of water was added to the boiling solution, and the heating time after the acid addition was 35 min. The H/V ratio was 0.75.

Subsequently, the beaker was removed from the heater and the stirring was stopped. The unwashed gel-like solid that did not settle after 1h was collected on filter paper by suction filtration. The product was filtered very slowly and the filtrate was orange indicating the presence of a significant amount of un-precipitated vanadium. The pH of the filtrate was measured using multi-color pH paper and was about 3. The filter cake was spread on a large coverslip and placed in the chamberDried warm for 4 days and then under an infrared heating lamp for 2 hours to obtain 12.5g of a dry powder. One impurity phase, believed to be Li₂SO₄.H₂O, as seen from x-ray diffraction. The inactive impurities have a diluting effect on the active material and reduce the total lithium insertion capacity. The product yield was estimated to be 65%.

Obtained V₂O₅.nH₂The O dry powder was then processed and combined as described in example 1 to form a 108 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 265 mAh/g.

Example 3

18.2g LiVO₃Combined with 900mL of deionized water and then treated as in example 1 to form V₂O₅.nH₂O, except that dilute sulfuric acid prepared by mixing 4.8mL of concentrated sulfuric acid with 20mL of water was added to the boiling solution, and the heating time after the acid addition was 15 min. The H/V ratio was 1.0.

Subsequently, the beaker was removed from the heater and the stirring was stopped. The solid was allowed to settle until the beaker had cooled to the touch. About 400mL of the supernatant was decanted. The decanted supernatant was light yellow, indicating the presence of some non-precipitated vanadium.

About 400mL of fresh water was added to the sediment in the beaker, then water was added and stirred for about 1min to make a slurry. The precipitate was allowed to settle for 10min, then about 500mL of supernatant was decanted. About 500mL of fresh water was added and slurried for 1 min. The precipitate was allowed to settle for about 20min and the supernatant was again decanted off.

The solid was collected on filter paper by suction filtration. The pH of the filtrate was measured using multi-color pH paper and was about 3. The filter cake was spread on a large glass coverslip and dried under an infrared heating lamp to yield 17.2g of dry powder. The composition (Li) is converted from chemical and thermogravimetric analysis_0.14V₂O₅(SO₄)_0.071.1H₂And O. From this composition, the product yield was calculated to be 97%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Obtained V₂O₅.nH₂Ogan (O)The dry powder was then processed as described in example 1 andthe combined 115 μm thick electrodes were formed and incorporated into button cells as in example 1, and the initial discharge capacity was found to be 355 mAh/g.

Example 4

In a 600mL Pyrex beaker, 50.0g anhydrous V₂O₅And 23.1g LiOH₂O was mixed with 350mL of deionized water under stirring with a teflon-coated magnetic stirrer and heated to about 80 ℃ to form a solution. 50mL of concentrated HCl was added to the hot solution with stirring. The H/V ratio was 1.1. After 15min, heating and stirring were stopped and the slurry was cooled to room temperature.

The solid was deposited on the filter paper by suction filtration. The filter cake was dried overnight under an infrared heating lamp, then reslurried with about 500mL of fresh deionized water, again collected on filter paper by suction filtration, and dried under an infrared lamp. According to thermogravimetric analysis and assuming a two-step reaction Converted to the composition Li_0.2V₂O₅Cl_0.2.0.5H₂And O. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Obtained V₂O₅.nH₂The O dry powder was then processed as described in example 1, combined, except that the amounts of active material, EPDM binder and carbon black were 90%, 2% and 8 wt%, respectively, to form a 90 μm thick electrode, and the electrode was incorporated into a button cell as in example 1, with an initial discharge capacity of 378 mAh/g.

Example 5

20.1g NH₄VO₃Combined with 450mL of deionized water and then treated as in example 1 to form V₂O₅.nH₂O, except that 15mL of concentrated nitric acid was added to the boiling solution and the heating time after the acid addition was 5 min. The H/V ratio was 1.4.

Subsequently, the beaker was removed from the heater and stirring was continued until the beaker had cooled to the touch. The solid was collected on filter paper by suction filtration. Then, the wet solid isThe slurry was made up of 350mL fresh deionized water with magnetic stirrer for 1min and then collected as before. The solid was again slurried with a portion of 350mL fresh water and collected as described above. The pH of the filtrate is then about 3. The filter cake was air dried at 110 ℃. 15.4g of product are obtained. The composition (NH) was converted from thermogravimetric analysis₄)_0.1V₂O₅(NO₃)_0.10.8H₂And O. From this composition, the product yield was calculated to be 88%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Obtained V₂O₅.nH₂The O dry powder was then processed and combined as described in example 1 to form a 125 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 367 mAh/g.

Example 6

18.2g LiVO₃Combined with 450mL of deionized water and then treated as in example 1 to form V₂O₅.nH₂O except that 15mL of concentrated nitric acid was carefully added to the boiling solution and the heating time after the acid addition was 10 min. The H/V ratio was 1.4.

Subsequently, the beaker is removed from the heater and allowed to cool to approximately room temperature. The solid was collected on filter paper by suction filtration. The wet solid was then slurried in 400mL of fresh deionized water with a magnetic stirrer for 1min and then collected as above. The pH of the filtrate was measured using multi-color pH paper and was about 1. The filter cake was dried under an infrared heating lamp. 15.5g of product are obtained. The composition (Li) is converted from chemical and thermogravimetric analysis_0.05V₂O₅(NO₃)_0.051H₂And O. From this composition, the product yield was calculated to be 89%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Obtained V₂O₅.nH₂The O dry powder was then processed and combined as described in example 1 to form a 110 μm thick electrode, and the electrode was incorporated into a button cell as in example 1The initial discharge capacity was found to be 340 mAh/g.

Example 7

20.1g NH₄VO₃Combined with 900mL of deionized water and then treated as in example 5 to produce V₂O₅.nH₂O, except that the heating time after the addition of the acid was 20 min.

Subsequently, the beaker was removed from the heater and the stirring was stopped. The solids settled quickly and were allowed to settle for 5 min. About 600mL of the supernatant was decanted. The decanted supernatant was light yellow, indicating the presence of some non-precipitated vanadium. About 700mL of fresh water was added to the sediment in the beaker and then slurried with water by stirring for about 1 min. The precipitate was allowed to settle for 10min and 700mL of supernatant was decanted. About 700mL of fresh water was added and the slurry was slurried for 1 min. The precipitate was allowed to settle for about 20min and the supernatant was again decanted off. The pH of the supernatant was about 2. The product was collected on filter paper by suction filtration smoothly and quickly. The wet cake was crushed and spread on a large glass cover and dried in air at room temperature for 3.5 days, resulting in 15.8g of material. The fluffy product was easily ground to a powder in a mortar. The composition (NH) was converted from thermogravimetric analysis₄)_0.1V₂O₅(NO₃)_0.10.7H₂And O. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O. From this composition, the product yield was calculated to be 91%.

Obtained V₂O₅.nH₂The O dry powder was then processed and combined as described in example 1 to form a 130 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 370 mAh/g.

Example 8

8.2g NH₄VO₃Combined with 150mL of deionized water and then treated as in example 1Generating V₂O₅.nH₂O, except that 6.6mL of concentrated nitric acid was added and the heating time after the acid addition was 2 min. The H/V ratio was 1.5.

Subsequently, the beaker was removed from the heater and stirring was continued until the beaker was warm to the touch. The product was collected on the filter paper smoothly and rapidly by suction filtration. The unwashed filter cake was dried overnight under an infrared heating lamp.

The composition (NH) was converted from thermogravimetric analysis₄)_0.1V₂O₅(NO₃)_0.11H₂And O. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Obtained V₂O₅.nH₂The O dry powder was then processed as described in example 1, combined, except that the active material, EPDM binder and carbon black were used in amounts of 90%, 2% and 8% by weight, respectively, to form a 120 μm thick electrode, and the electrode was incorporated into a button cell as in example 1, and the initial discharge capacity was found to be 383 mAh/g.

Example 9

18.3g MgV₂O₆V was made as in example 3₂O₅.nH₂O except that a solution of 9.5mL of concentrated sulfuric acid in 20mL of deionized water was added and the H/V ratio was 2.1.

Subsequently, the beaker was removed from the heater and the stirring was stopped. The solids settled quickly and were allowed to settle for 5 min. About 700mL of the supernatant was decanted. The decanted supernatant was light yellow, indicating the presence of some non-precipitated vanadium. About 700mL of fresh water was added to the sediment in the beaker and then slurried with water by stirring for about 1 min. The precipitate was allowed to settle for 10min and 700mL of supernatant was decanted. This washing/decanting step was repeated two more times. The pH of the supernatant from the last wash is between 3 and 4. The product was collected on filter paper by suction filtration smoothly and quickly. The wet cake was crushed and spread on a large glass cover and dried in air at room temperature for 2.5 days, and then under an infrared heating lamp for 5 hours, to obtain 16.3g of a material. The product was easily ground to a powder in a mortar. The product yield was estimated to be 96%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Obtained V₂O₅.nH₂The O dry powders were then processed and combined as described in example 1 to form 123 μm thick electrodesAnd the electrode was incorporated into a button cell as in example 1, the initial discharge capacity was found to be 365 mAh/g.

Example 10

20.1g NH₄VO₃Combined with 900mL of deionized water and then treated as in example 1 to make V₂O₅.nH₂O except that a solution of 9.6mL of concentrated sulfuric acid in 25mL of deionized water was added and the heating time was 20 minutes after the acid addition. The H/V ratio was 2.

Subsequently, the beaker was removed from the heater and the stirring was stopped. The solids settled quickly. Pressing and compactingThe washing was carried out as in example 7. The final supernatant had a pH of 2. The product was collected on filter paper by suction filtration smoothly and quickly. The wet cake was crushed, spread on a large glass cover and dried in the typical manner, resulting in 16.2g of product. The bulk material was easily ground to a powder in a mortar. The composition (NH) is converted from chemical and thermogravimetric analysis₄)_0.12V₂O₅(SO₄)_0.060.8H₂And O. From this composition, the product yield was calculated to be 92%. SEM images at 30,000 magnification showed that the product was non-fibrous. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Subsequently, V obtained₂O₅.nH₂The O dry powder was processed and combined as described in example 1 to form a 130 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 370 mAh/g.

Example 11

Example 10 was repeated except that a solution of 9.6mL of concentrated sulfuric acid in 40mL of deionized water was used and the heating time after the acid addition was 60 min. The H/V ratio was 2. 15.4g of product are recovered.

The composition (NH) was converted from thermogravimetric analysis₄)_0.12V₂O₅(SO₄)_0.060.6H₂And O. From this composition, the product yield was calculated to be 89%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Subsequently, V obtained₂O₅.nH₂The O dry powder was processed and combined as described in example 1 to form a 125 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 374 mAh/g.

Example 12

Example 7 was repeated, except that 30mL of concentrated nitric acid was used, and the H/V ratio was 2.8. After washing and drying as in example 7, 12.4g of material was collected. The composition (NH) was converted from thermogravimetric analysis₄)_0.09V₂O₅(NO₃)0_.090.5H₂And O. From this composition, the product yield was calculated to be 73%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Subsequently, V obtained₂O₅.nH₂The O dry powder was processed and combined as described in example 1 to form a 115 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 350 mAh/g.

Example 13

Example 10 was repeated except that a solution of 19.2mL of concentrated sulfuric acid in 40mL of deionized water was used. The H/V ratio was 4. 13.6g of product are recovered. The composition (NH) was converted from thermogravimetric analysis₄)_0.12V₂O₅(SO₄)_0.061H₂And O. From this composition, the product yield was calculated to be 76%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Subsequently, V obtained₂O₅.nH₂The O dry powder was processed and combined as described in example 1 to form a 115 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 325 mAh/g.

Example 14

Example 3 was repeated except that a solution of 19.2mL of concentrated sulfuric acid in 50mL of deionized water was added and the heating time after the addition of the acid was 20 min.The H/V ratio was 4. After washing and drying, 10.8g of product are obtained. The product yield was estimated to be 62%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Subsequently, V obtained₂O₅.nH₂The O dry powder was processed and combined as described in example 1 to form a 98 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 321 mAh/g.

Example 15

Example 10 was repeated except that a solution of 28.8mL of concentrated sulfuric acid in 50mL of deionized water was used. The H/V ratio was 6. 9.6g of product were recovered. The product yield was estimated to be 55%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Subsequently, V obtained₂O₅.nH₂The O dry powder was processed and combined as described in example 1 to form a 105 μm thick electrode and the electrode was incorporated into a button cell as in example 1 and the initial discharge capacity was found to be 272 mAh/g.

Example 16

In a 1L Pyrex beaker, 20.1g NH₄VO₃Added to about 900mL of deionized water with stirring with a teflon-coated magnetic stirrer. The contents of the beaker are heated to boiling point, resulting in a solution. 1.56g of commercially available Super P carbon black of MMM S.A. carbon (Brussel, Belgium) was slurried in 100mL of deionized water by shaking, and the resulting slurry was stirred into the boiling solution in an amount that would yield a carbon content in the product of about 8 wt%.

The vanadium solution/carbon black mixture was reheated to boiling point with stirring.

9.6mL of concentrated sulfuric acid is diluted in 30-40 mL of deionized water, and the diluted acid is added to the boiling solution under stirring. The H/V ratio was 2. The resulting mixture was boiled for a further 15min with stirring.

Subsequently, the beaker was removed from the heater and stirring was continued for 1 h. The solids were allowed to settle for about 5 min. The warm supernatant was decanted off.

The precipitate was reslurried in a fresh aliquot of water for about 1 h. The precipitate was allowed to settle again for about 10min and the supernatant decanted. A second aliquot of fresh water was added and the washing and solids separation process was repeated.

The washed, settled precipitate was collected on filter paper by suction filtration. The filter cake was chopped into small pieces and dried in air for about 64h, then dried under an infrared heating lamp for 4 h. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

After grinding to a powder, the powder was sieved through a 200 mesh screen to obtain a powder suitable for the manufacture of cathodes. The product was shown to be non-fibrous under Scanning Electron Microscope (SEM) magnification to 30,000 times.

2 electrodes were made with different binders. An electrode was fabricated as described in example 1, forming a 120 μm thick electrode, which was incorporated into a button cell as in example 1, and the initial discharge capacity was found to be 350 mAh/g.

As another electrode, 1.0000g of this powder was mixed with 0.1000g of MMM Super P carbon, 0.1539g of Kynarflex (Elf Atochem), 0.285g of dibutyl phthalate and 4.6mL of acetone. The mixture was shaken on a mechanical shaker in a glass vial with a lid for 15 min.

The cathode paste was spread to Teflon^®FEP, and drawn into a film using a 10 mil gap doctor blade. After evaporation of the acetone, the dibutyl phthalate is extracted with dimethyl ether. Dried film consisting of 79.8% by weight of active powder, 12.2% by weight of binder and 8% by weight of carbon black, passed through calendering rolls in a Kapton^®Polyamide sheets (dupont) were thermoformed between sheets at 2000psi and 110 c to form a dense electrode sheet suitable for use as a cathode in a lithium battery. The sheet thickness was 86 μm.

The cathode disk sheet was die cut and incorporated into a button cell as described in example 1. The initial discharge capacity was found to be 357 mAh/g.

Example 17

The electrode of example 16 was used as a cathode in a lithium ion chemical cell. The anode consisted of lithiated graphite, which was formed by reacting thin disks of lithium metal and graphite in a button cell at room temperature.

6.0000g of graphite powder MCMB25-28 (Osaka gas Co., Japan) was mixed with 0.1936g of super P carbon black (MMM S.A. carbon, Brussel, Belgium) and 6.452g of a 4 wt% solution of EPDM rubber in cyclohexane. 2.0mL of additional cyclohexane was added to improve flow. The mixture was shaken on a mechanical shaker for 15min in a glass vial with a cap, resulting in the formation of a graphite paste.

The graphite paste was spread on Teflon^®FEP sheet (DuPont, Wilmington DE)And drawn into a film using a 40 mil gap doctor blade. After drying, the film, consisting of 93 wt% graphite, 4 wt% binder and 3 wt% carbon black, was passed through calendering rolls in a Kapton^®Polyimide sheets (dupont) were thermoformed between sheets of polyimide at 2000psi and 110 c to form a dense electrode sheet. The thickness of the sheet was about 295 μm.

Disks of cathode, graphite, lithium metal and fiberglass separator were die cut with both stone and lithium metal operating in a glove box under a dry nitrogen atmosphere. In a glove box, the cathode and the separator sheet were immersed in LiPF₆In an electrolyte solution of EC/DMC (ethylene carbonate/dimethyl carbonate), subsequently stacked together with two graphite disks and a lithium disk, to give a button cell disk, the lithium disk being approximately 100 μm thick and being encapsulated under pressure on a 2325 button cell clamping machine system (manufactured by National institute of canada).

Button cells were left for 90h before testing. The amounts of graphite and lithium metal give a roughly LiC₁₀It is believed that this will ensure that no lithium metal remains in the button cell prior to testing. The button cell test was performed according to the standard method used herein except that the voltage was adjusted from 1.5-4.0V to 1.4-3.9V, since the voltage of the lithium-graphite anode was observed to be 0.09V with respect to lithium metal. In the case of the non-optimized button cell assembly described above, 92% of the initial discharge capacity equivalent to that obtained in example 16 was obtained from the lithium ion battery of this example.

Example 18

Example 10 was repeated except that the heated solution was cooled to room temperature before the addition of the acid.

After 10min, only a small amount of solid was formed. More solid was observed after 1h, and some more solid was formed after stirring overnight. The supernatant was found to contain soluble, non-precipitated vanadium. The supernatant was decanted and the solid slurried with fresh deionized water by stirring for about 1 min. The precipitate was allowed to settle for about 10 min. The supernatant was measured using multicolor pH paper and had a pH of 3. The washed, settled precipitate was collected on filter paper by suction filtration. The filter cake was chopped into small pieces and dried in air overnight. 14g were obtained.

The formation of the desired product was confirmed by X-ray powder diffraction. The composition (NH) was converted from thermogravimetric analysis₄)_0.14V₂O₅(SO₄)_0.071.1H₂And O. From this composition, the product yield was calculated to be 77%. X-ray powder diffractogram showing only V₂O₅.nH₂A line of O.

Subsequently, V obtained₂O₅.nH₂The O dry powders were processed and combined as described in example 1 to form a 120 μm thick electrode and the electrode was incorporated into a button cell as in example 1, and the lithium capacity was found to be 330mAh/g as described above.

Example 19

In a 1L Pyrex beaker, 20.1gNH₄VO₃Added to about 900mL of deionized water with stirring with a teflon-coated magnetic stirrer. The contents of the beaker were heated to boiling point, resulting in a solution, which was then cooled to room temperature. 19.2mL of concentrated sulfuric acid was diluted in 50mL of water and added to the solution with stirring. The acid proton/vanadium ratio was 4. After 4h, only traces of solids were formed.

Example 20

Example 10 was repeated except that the temperature of the solution was reduced to 45 ℃ before the acid was added.

The reaction was maintained at about 45 ℃ overnight. The acid proton/vanadium ratio is 2. The supernatant was found to contain some soluble non-precipitated vanadium.The supernatant was decanted and the solid slurried with fresh deionized water by stirring for about 1 min. The precipitate was allowed to settle for about 10 min. And (4) measuring the supernatant by using multicolor pH test paper, wherein the pH value is 2-3. The washed, settled precipitate was collected on filter paper by suction filtration. The filter cake was chopped into small pieces and dried in air to yield 15.8g of product. X-ray powder diffraction shows that the product is mainly composed of the required material, plus some (NH)₄)₂V₆O₁₆And (4) forming. V₂O₅.nH₂Yield of O, assumed (NH)₄)₂V₆O₁₆The impurity content is 10%, and is estimated to be 75 to 80%.

Subsequently, the obtained dry mixed-phase powders were processed and combined as described in example 1 to form a 120 μm thick electrode, and the electrode was incorporated into a button cell as described in example 1, and the lithium capacity was found to be 329mAh/g as described above.

Claims

1. Production MxV₂O₅Ay.nH₂O, wherein M is selected from NH₄ ⁺、Na⁺、K⁺、Rb⁺、Cs⁺And Li⁺(ii) a A is selected from NO₃ ^-、SO₄ ^-2And Cl^-(ii) a X is more than 0 and less than 0.7, and y is more than 0 and less than 0.7; and 0.1 < n < 2, the method comprising,

mixing vanadate with water to form a solution; and

2. The process of claim 1, further comprising, prior to adding the strong mineral acid, the step of heating the solution to a temperature in the range of from 80 ℃ to the boiling point of the solution.

3. The method of claim 1, further comprising the step of dispersing elemental carbon in solution prior to adding the acid.

4. The process of claim 1, wherein the molar ratio is from 1: 1 to 4: 1.

5. A process according to claim 1, wherein the concentration of vanadate in the solution is between 0.1 and 1M.

6. The process of claim 3 wherein the carbon concentration in the final product is carbon plus MxV₂O₅Ay.nH₂1-12 wt% of the total weight of O.

7. The process of claim 3 wherein the carbon concentration in the final product is carbon plus MxV₂O₅Ay.nH₂4-8 wt% of the total weight of O.

8. A composition containing non-fibrous MxV₂O₅Ay.nH₂O, wherein M is selected from NH₄ ⁺、Na⁺、K⁺、Rb⁺、Cs⁺And Li⁺(ii) a A is selected from NO₃ ^-、SO₄ ^-2And Cl^-(ii) a 0 < x < 0.7 and 0.1 < n < 2, said composition being characterized by an initial discharge capacity equal to 315-400 mAh/g.

9. The composition of claim 8, further comprising carbon plus MxV₂O₅Ay.nH₂1 to 12 wt% of elemental carbon based on the total weight of O, wherein MxV₂O₅Ay.nH₂O is present as a coating on carbon.

10. The composition of claim 9, wherein the composition comprises carbon plus MxV₂O₅Ay.nH₂4-8 wt% of elemental carbon based on the total weight of O.

11. An electrode comprising the composition of claim 8, 9 or 10.

12. An electrochemical cell comprising the electrode of claim 11.

13. The electrochemical cell of claim 12 in the form of a lithium or lithium ion battery.