JP5591205B2 - A novel lithium insertion electrode material based on orthosilicate derivatives - Google Patents

Description

  The present invention relates to novel lithium insertion electrode materials based on orthosilicate derivatives, electrochemical power generation devices and variable photoconductive devices having electrodes comprising these materials.

The electrode material is mainly a transition metal chalcogenide, in particular an oxide and has a lamellar structure, for example Li _x CoO ₂ or a spinel, for example Li _2x Mn ₂ O ₄ . These materials typically operate via a lithium insertion mechanism with exchanged lithium and electrons (0 ≦ x ≦ 0.6) less than 1 per transition metal in the unit formula. In addition, these materials suffer from the loss of transition metals that can easily be leached into the electrode. Cobalt is too expensive to be used on a large scale.
LiFePO ₄ of olivine type structure (Torifiru stone) and "□ FePO _4" homomorphic delithiated material shown as (where "□" means after exiting lithium), the flat plate of the discharge (lithiation) In the stable window of both liquid and polymer electrolyte with plateau, it has the advantage that the operating voltage is 3.5 V vs. Li ⁺ / Li ⁰ .

However, this material is limited by the relatively low Li ⁺ diffusion rate kinetics and electronic conductivity both due to the high electronegativity of the phosphate anion. The absence of non-stoichiometry or mutual miscibility in both phases (LiFePO ₄ and □ FePO ₄ ) is advantageous in terms of the shape of the discharge curve, but eventually the material is fragmented at a high current density, It also limits the kinetics of phase transitions that reduce contact with carbon particles acting as current collectors. This type of phosphate offers the possibility of exchanging only one lithium per unit formula.
Conversely, Li ₂ SO ₄ , Li ₃ PO ₄ , Li ₄ SiO ₄ and their composite solutions are known to have relatively high diffusion coefficients for lithium ions, but no redox activity. ing.

In the present invention, an orthosilicate containing SiO ₄ ^4- tetranion as a building block is used as a redox material by incorporating at least one divalent transition metal. Lithium enters and exits the structure to compensate for changes in the valence of the redox conjugate acting as an electrode and to maintain overall electrical neutrality.

The general formula of the material of the present invention is as follows:
Li _x M _{m- (d + t + q + r)} D _d T _t Q _q R _r [SiO ₄ ] _{1- (p + s + g + v + a + b)} [SO ₄ ] _s [PO ₄ ] _p [GeO ₄ ] _g [VO ₄ ] _v [AlO ₄ ] _a [BO ₄ ] _b
Where
M means Mn ²⁺ or Fe ²⁺ and mixtures thereof;
D is a metal in the +2 oxidation state and means a metal selected from Mg ²⁺ , Ni ²⁺ , Co ²⁺ , Zn ²⁺ , Cu ²⁺ , Ti ²⁺ , V ²⁺ , and Ca ²⁺ ;
T is a metal in the +3 oxidation state, meaning a metal selected from Al ³⁺ , Ti ³⁺ , Cr ³⁺ , Fe ³⁺ , Mn ³⁺ , Ga ³⁺ , Zn ³⁺ , V ³⁺ ;
Q is a metal in the +4 oxidation state, meaning a metal selected from Ti ⁴⁺ , Ge ⁴⁺ , Sn ⁴⁺ , V ⁴⁺ ;
R is a metal in the +5 oxidation state, meaning a metal selected from V ⁵⁺ , Nb ⁵⁺ , Ta ⁵⁺ ;
M, D, T, Q, R are all elements located in octahedral or tetrahedral sites;
s, p, g, v, a and b are S ⁶⁺ (sulfate), P ⁵⁺ (phosphate), Ge ⁴⁺ (germanate), V ⁵⁺ (vanadate), Al located in the silicon tetrahedral site. ³⁺ is (aluminate) and B ³⁺ (borate) stoichiometric coefficient corresponding to each.
The stoichiometric coefficients d, t, q, r, p, s, v, a, and b are all positive numbers and are numbers between 0 (including) and 1 (including). Other conditions are:
0 ≦ x ≦ 2; 1 ≦ m ≦ 2; p + s + v + a + b <1 (not included)
x + 2m + t + 2q + 3r = 4-p-2s-v + a + b.

Silicon is the second most abundant element in the crust, and the silicate structure is chemically strong and therefore electrochemically stable. In addition to iron and manganese, preferred transition metals are selected from: titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, niobium and tantalum. Composites containing large amounts of iron and / or manganese are preferred because they are rich in these elements and are not toxic. In addition, fixed valence or redox metals with potentials outside the working region of the electrode may be partially replaced with transition elements to improve lithium ion diffusion properties and / or to increase the number of sites available. It can be increased to help control particle size and to allow the presence of a continuous solid solution between the oxidized and reduced forms of the electrode material. These elements are preferably selected from lithium, magnesium, calcium, zinc, aluminum, gallium and tin. For example, given the coexistence of iron and / or manganese in two different oxidation states in the same phase, these substitutions are specific interactions with other elements at levels similar to the redox level of iron and manganese. (For example, Fe ²⁺ / Ti ⁴⁺ ⇔Fe ³⁺ / Ti ³⁺ , Mn ²⁺ / V ⁵⁺ ⇔Mn ³⁺ / V ⁴⁺ etc.), both of which are preferable for electron conduction, anions Sex site mismatch provides preferential diffusion over Li ⁺ .

Another aspect of the present invention relates to the possibility of replacing the silicon site with various elements. The orthosilicate anion is equivalent to the sulfate, phosphate, germanate and vanadate anions and, like boron and aluminum, in this type of structure, the corresponding element easily replaces silicon and charges at the anionic site. Provides a wide selection of materials that fully control density. Similarly, the tendency of orthosilicates to accommodate large amounts of bond vacancies and intermediate ions is highly favorable for the diffusion of lithium ions while retaining the structure uniformly during the lithium entry and exit process.
The material of the present invention preferably has an orthorhombic structure determined by X-ray and electron diffraction for low and high temperature type lithium phosphates (a and b types), with metal ions remaining. seven unoccupied tetrahedral sites or four octahedral sites (ASTM N ^o 25-1020 and 15-760) or partially occupied lithium orthosilicate Li ₄ SiO ₄ "staff Boom run stone type" structure Partially occupy any of the. Volume wells greater than 160 mAh / g can be obtained, which is superior to conventional electrode materials. Another advantage of the material of the present invention is that it prevents the transition metal from leaching to the electrode, which is an orthosilicate anion SiO ₄ ⁴⁻ that selectively binds multiple charged cations containing transition elements. This is because of the high charge.

The composites of the present invention are particularly useful when used alone or in electrochemical cells and other redox-active composites as components of stable electrode materials in primary or secondary batteries where the negative electrode is a lithium ion source. It is a case where it mixes with and uses. Typical examples are not intended to limit, metal lithium, lithium alloys, such as SnO or alloy of nanodispersion in lithium oxide matrix obtained by reducing the SnO ₂ (nanodispersion), carbon, in particular graphite or A compound in which lithium is inserted into a carbon material obtained by pyrolyzing an organic derivative such as petroleum coke or polyparaphenylene, and a general formula Li _{1 + y} Ti _{2-x / 4} O ₄ (independently 0 ≦ x ≦ 1, 0 ≦ y ≦ 1) lithium-titanium spinel and its solid solution with other spinels or lithium-transition metal mixed nitrides such as Li _3-x Co _x N (0 ≦ x ≦ 1). These materials can be used alone or in combination.
Other applications include use in supercapacitors or as counter electrodes for controlled reflection-transmission windows (“smartwindows”), which are in different oxidation states. This is due to the low light absorption of some composites.

  The composites of the present invention are readily produced by inorganic chemistry and ceramic techniques known to those skilled in the art. In general, the elemental oxides, salts or derivatives incorporated into the final composition of the material are mixed in a predetermined ratio and heated at that temperature to ensure a reaction. Preferably, the metal salt is a salt derived from an anion that readily decomposes at moderate temperatures to release the oxide. These include organic salts such as acetates, oxalates and generally salts of carboxylic acid derivatives, beta diketones, alkoxides or mixtures thereof. Likewise preferred inorganic salts are selected from hydroxides, nitrates, carbonates, sulfates. The so-called sol-gel technique is particularly appreciated because it allows the incorporation of elements in a highly dispersed form, resulting in a uniform powder with controllable particle size at relatively low temperatures. It is because it is obtained. Silicon alkoxides are particularly useful for this purpose because they are hydrolyzed at room temperature into silica precursors, and the silica gel thus formed has a large surface area and is a homogeneous material upon heat treatment. This is because a large amount is adsorbed. A wide selection of silicon, titanium, germanium, aluminum derivative alkoxides is commercially possible. Variations on this technique include elemental coprecipitation from aqueous or non-aqueous media and the Pechini method, in which polyester polyacids are formed in solution and chelate ions from solution, then dried and Thermally decomposes. Control of the degree of oxidation of elements, especially transition metals, can be achieved by operating in a controlled environment. A low oxygen partial pressure can be maintained by a vacuum, an inert gas or a reducing mixture such as hydrogen or a carbon monoxide / carbon dioxide mixture. Thus, a well-defined oxygen activity can be obtained from known thermodynamic data. Conversely, the valence state of the transition metal is increased by air or oxygen.

The redox state of the material can also be controlled by chemical extraction or insertion of lithium from the structure, which mimics electrode manipulation. Lithium known oxidizing agents that can be extracted, bromine, chlorine, iodine, nitrosonium or nitronium salts stable anions, e.g. NO ⁺ BF ₄ ^- or NO ₂ ⁺ PF ₆ ^- can be selected from, in this It is not limited. The reducing agent can be selected from, but is not limited to, iodide ions, LiBH ₄ , free radical anion derivatives of lithium with condensed aromatic nuclei (naphthalene, anthracene, benzophenone), organometallic reagents such as butyl lithium, lithium thiolate. Not what you want. The desired lithium content of the composite of the present invention can also be obtained electrochemically.
The following examples are presented to illustrate the present invention and should not be construed as limiting its scope.

Reference example 1
20.4 g lithium acetate dihydrate Li (C ₂ H ₃ O ₂ ) · 2 (H ₂ O), 24.5 g manganese acetate tetrahydrate (Mn (C ₂ H ₃ O ₂ ) in 90 ml water and 10 ml methanol ) ₂ · 4 (H ₂ O)) and 14.8 ml of tetramethoxysilane are added. The mixture is ground for 60 hours with zirconia pellets in a thick-walled plastic container on a roller mill. The dense slurry is put into a PTFE evaporating dish and air is circulated in an oven to dry at 90 ° C. The resulting material is powdered in a mortar and heat treated at 350 ° C. in air to remove organic residues. The resulting brown-green powder is transferred to an alumina boat and the composite is treated at 800 ° C. in an electric furnace with a reducing air stream containing 8% hydrogen diluted with argon. 13 g of Li ₂ MnSiO ₄ are obtained (yield 81%).

Reference example 2
71.8 g ferrous oxide FeO and 89.9 g lithium metasilicate Li ₂ SiO ₃ are ball milled with high carbon steel balls for 4 hours. The resulting mixture is transferred to a quartz ampoule and a small amount of iron turnings is added. The ampoule is evacuated and sealed under a second vacuum while maintaining 200 ° C. The following reaction
FeO + Li ₂ SiO ₃ ⇒Li ₂ FeSiO ₄
Is completed at 800 ° C for 4 hours. After cooling, the ampoule is opened under an argon atmosphere, and the iron turning is removed magnetically.

Reference example 3
Iron protooxide FeO (71.8 g) and lithium metasilicate Li ₂ SiO ₃ (90 g) are ball milled with high carbon steel balls for 4 hours. The resulting mixture is transferred to a quartz ampoule and a small amount of iron turnings is added. The ampoule is evacuated and sealed under a second vacuum while maintaining 200 ° C. The following reaction
FeO + Li ₂ SiO ₃ ⇒Li ₂ FeSiO ₄
Is completed at 800 ° C for 4 hours.

Reference example 4
21.6 g of iron oxalate dihydrate, 1.79 g of manganese oxalate dihydrate and 5.17 g of lithium carbonate were added to 13.4 g of polydiethoxysiloxane (Gelest Inc, 100 ml of 96% ethyl alcohol as in Reference Example 1). Tullytouwn PA, ground in a USA catalog N ^o PSI-023). The resulting slurry is evaporated and calcined in air at 500 ° C. The cake is ground in a ball mill for 20 minutes and the resulting powder is treated in the presence of an equal mixture of CO ₂ and CO in a tubular furnace at 1050 ° C. for 10 hours. The resulting composite has the formula Li _1.4 Fe _1.2 Mn _0.1 SiO ₄ .

Reference Example 5
19.4 g of lithium acetate dihydrate Li (C ₂ H ₃ O ₂ ) · 2 (H ₂ O), 19.6 g of manganese acetate tetrahydrate Mn (C ₂ H ₃ O ₂ ) ₂ · 4 ( H ₂ O), 14.8 ml tetramethoxysilane and 2.75 ml isopropanol diluted in 20 ml titanium tetraisopropoxide. The mixture is ground for 60 hours with zirconia pellets in a thick-walled plastic container on a roller mill. The slurry is opened in a PTFE evaporating dish and dried at 80 ° C. in an air circulating oven. The resulting material is powdered in a mortar and heat treated at 350 ° C. in air to remove organic residues. The resulting powder is transferred to an alumina boat and the composite is treated as in Reference Example 1 at 800 ° C. with a reducing stream containing 8% hydrogen diluted with argon. A composite corresponding to the formula Li _1.9 Mn _0.8 Ti _0.1 SiO ₄ is obtained, where Ti is in the +3 state and manganese is divalent.

Reference Example 6
3 g of the composite Li ₂ FeSiO ₄ of Reference Example 2 is suspended in 20 ml of acetonitrile and treated with 1.7 g of bromine with stirring at room temperature. After 2 hours, the suspension is filtered and washed with acetonitrile, leaving a solid with the composition Li ₁ FeSiO ₄ . This corresponds to an electrode capacity of 172 mAh / g. Similarly, 7 g of the material of Reference Example 4 is treated with 3 g of bromine in 50 ml of acetonitrile. After filtration, the material Li _0.1 Fe _1.2 Mn _0.1 SiO ₄ is obtained. This corresponds to an electrode capacity of 260 mAh / g.

Reference Example 7
5 g of the composite Li ₂ MnSiO ₄ of Reference Example 1 is suspended in 40 ml of nitromethane and treated with 12 g of nitronium hexafluorophosphate NO ₂ PF ₆ with stirring at room temperature. After 2 hours, the suspension is filtered and washed with nitromethane leaving a brown-purple solid having the composition MnSiO ₄ . This corresponds to an electrode capacity of 345 mAh / g.

Example 8
8 g of the composite Li ₂ MnSiO ₄ of Reference Example 1 and 3.36 g of lithium iron phosphate LiFePO ₄ in an inert atmosphere until the particle size does not exceed 4 μm (4 microns), and then pulverized by a ball mill with a steel ball Do. The mixture is placed in a nickel tube closed at one end and welded under vacuum. The tube is treated at 750 ° C. for 10 hours and allowed to cool to room temperature. The resulting solid solution has the formula Li _1.7 Mn _0.7 Fe _0.3 Si _0.7 P _0.3 O ₄ .

Reference Example 9
A solid state battery using a 10 mm lithium anode coated with 10 mm nickel foil, a 25 mm polymer electrolyte and a 45 mm positive electrode is constructed with a 4 cm ² active surface. The electrolyte is a cross-linked condensation polymer having lithium trifluoromethanesulfonimide Li (CF ₃ SO ₂ ) ₂ N as a solute, corresponding to a ratio of oxygen to Li ⁺ from the ether group of the polymer of 16: 1. Electrochem. Soc. 141-7, 1915 (1994) and Journal of Power sources, 54-1, 40 (1995). The positive electrode was made from 53% by volume of PEO with a molecular weight of 200,000, 40% by volume of the material of Reference Example 4 and the delithiated material according to Reference Example 6, and 7% by volume of Ketjenblack® in acetonitrile. Obtained by coating technique on aluminum foil. 1.2 lithium per formula unit can be circulated between 3.5 and 2.4 volts.

Reference Example 10
A gel-type rocking chair ("lithium ion") battery is coated with a 40mm anode made from graphite flakes (4mm) containing 5% by volume ethylene-propylene-diene binder, and 10mm copper foil, and vinylidene fluoride. Fume with mixed solvent gelled with liquid electrolyte (65% by weight) consisting of 1.2 mol lithium hexafluorophosphate in 30% by weight of hexafluoropropylene copolymer (Solvay, Belgium), equal amount of ethylene carbonate-ethyl methyl carbonate Consists of 45 mm electrolyte containing dosilica (5% by weight). The positive electrode consists of a mixture of the electrode material of Reference Example 5 (80% by weight), Ketjenblack® and the vinylidene-hexafluoropropylene copolymer (12% by weight) used in the electrolyte. Place the battery in a flat metal-plastic coated container so that current leads can pass through it. At 25 ° C, 1.3 lithium per manganese can be exchanged at the positive electrode within the range of 2-4.3 volts by battery operation.
Although the present invention has been described in connection with specific embodiments thereof, further variations are possible, and the present invention generally follows the spirit of the invention and from this description as known or practiced in the art. Modifications, which are intended to include all modifications, uses or adaptations of the invention, including deviations from, and which are applicable to the essential features described above and within the scope of the appended claims, It is intended to include all uses or indications.
Moreover, this invention can be the following aspects.
[1]
Lithium-insertion-type electrode material based on an orthosilicate structure and having the following general formula:
Li _x M _{m- (d + t + q + r)} D _d T _t Q _q R _r [SiO ₄ ] _{1- (p + s + g + v + a + b)} [SO ₄ ] _s [PO ₄ ] _p [GeO ₄ ] _g [VO ₄ ] _v [AlO ₄ ] _a [BO ₄ ] _b
Where
M means Mn ²⁺ or Fe ²⁺ and mixtures thereof;
D means a metal in the +2 oxidation state including Mg ²⁺ , Ni ²⁺ , Co ²⁺ , Zn ²⁺ , Cu ²⁺ , Ti ²⁺ , V ²⁺ , Ca ²⁺ ;
T means a metal in the +3 oxidation state including Al ³⁺ , Ti ³⁺ , Cr ³⁺ , Fe ³⁺ , Mn ³⁺ , Ga ³⁺ , Zn ³⁺ , V ³⁺ ;
Q means a metal in the +4 oxidation state, including Ti ⁴⁺ , Ge ⁴⁺ , Sn ⁴⁺ , V ⁴⁺ ;
R means a metal in the +5 oxidation state including V ⁵⁺ , Nb ⁵⁺ , Ta ⁵⁺ ;
M, D, T, Q, R are elements located in octahedral or tetrahedral sites;
s, p, g, v, a and b are S ⁶⁺ (sulfate), P ⁵⁺ (phosphate), Ge ⁴⁺ (germanate), V ⁵⁺ (vanadate), Al located in the silicon tetrahedral site. ³⁺ be (aluminate) and B ³⁺ (borate) stoichiometric coefficient corresponding to each;
The stoichiometric coefficients d, t, q, r, p, s, v, a, b are all positive numbers and are numbers between 0 (including) and 1 (including);
0 ≦ x ≦ 2; 1 ≦ m ≦ 2; p + s + v + a + b <1 (not included); and
x + 2m + t + 2q + 3r = 4-p-2s-v + a + b.
[2]
The electrode material according to [1], which has a crystal structure that matches the crystal structure of lithium phosphate or lithium orthosilicate.
[3]
The electrode material according to [1] and [2], wherein more than one lithium ion can be extracted or inserted per unit formula.
[4]
At least one positive electrode and one negative electrode, characterized in that at least one positive electrode comprises a material of [1] and [2] and at least one negative electrode is a lithium ion source in high chemical activity Having an electricity generator.
[5]
The cathode is a metallic lithium, lithium alloy, as much nano-dispersion as possible in lithium oxide, a lithium insertion composite of carbon material obtained from pyrolysis of carbon or organic derivatives, lithium-titanium spinel Li _{1 + y} Ti _{2 -x / 4} O ₄ (where 0 ≦ x ≦ 1, 0 ≦ y ≦ 1) and solid solutions thereof with other spinels, or lithium-transition metal mixed nitrides and mixtures thereof, 4] The electricity generator.
[6]
The electricity generator according to [4], wherein the conductive additive is present in the positive electrode.
[7]
The electricity generator according to [5], wherein the conductive additive in the positive electrode material is carbon.
[8]
The positive electrode has the formula Li _λ Fe _f Mn _m Si _s P _p O ₄ (where f + m ≦ 1.2; s + p = 1; 0 ≦ p ≦ 0.6; 8-5p-4s-2m-2f ≧ λ ≧ 8-5p-4s-4m-3f) [4] The electricity generator characterized by including the material.
[9]
[4] The electricity generating device according to [4], wherein the positive electrode includes another insertion material in addition to the material of [1].
[10]
The insertion material is a Nasicon-like material such as lamellar dichalcogenide , vanadium oxide VO _x (2.1 ≦ x ≦ 2.5) or Li ₃ Fe ₂ (PO ₄ ) _{3 according} to [9] Electricity generator.
[11]
The electricity generator according to [4] to [7], wherein the positive electrode contains a polymerizable binder.
[12]
The electricity generator according to [4] and [11], wherein the polymerizable binder is a homopolymer or copolymer of tetrafluoroethylene or an ethylene-propylene-diene terpolymer.
[13]
[12] The electricity generator according to [12], wherein the positive electrode contains an aprotic solvent and a salt, and the cation is at least partially Li ⁺ .
[14]
The electricity generator of [4] and [11], wherein the polymerizable binder has ionic conductivity.
[15]
[13] The electricity generator according to [13], wherein the polymerizable binder is a crosslinked or non-crosslinked polyether, dissolves a salt, and its cation is at least partially Li ⁺ .
[16]
The electricity generator according to [11], wherein the polymerizable binder swells with an aprotic solvent and contains a salt, and the cation is at least partially Li ⁺ .
[17]
[11] The electricity generating device according to [11], wherein the polymerizable binder is a polymer mainly composed of polyether, polyester, or methyl methacrylate, a polymer mainly composed of acrylonitrile, or a polymer mainly composed of vinylidene fluoride.
[18]
Aprotic solvent is ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl-ethyl carbonate, γ-butyrolactone, tetraalkylsulfamide, mono-, di-, tri-, tetra- or higher molecular weight of 2000 or less The electricity generator according to [13] and [16], which is a dialkyl ether of oligo-ethylene glycol and a mixture thereof.
[19]
A supercapacitor-type electricity generator, wherein at least one electrode includes the materials [1] and [2].
[20]
A variable photoconductive device comprising a transparent semiconductor coated with glass or plastic and two electrodes separated by a solid or gel electrolyte, wherein at least one electrode comprises the material [1] .
[21]
At least one electrode is obtained by placing a thin film of the material of [1] on a transparent semiconductor coated with glass or plastic from a vacuum deposition technique, sputtering or from a sol-gel precursor. [20] The variable photoconductive device.

Claims (21)

Lithium ion reversible insertion type electrode material having an orthosilicate structure and having the following formula:
Li _x M _mt T _t [SiO ₄ ] _1-p [PO ₄ ] _p
Where
M means Mn ²⁺ or Fe ²⁺ and mixtures thereof;
T means a metal in the +3 oxidation state selected from the group consisting of Al ³⁺ , Ti ³⁺ , Cr ³⁺ , Fe ³⁺ , Mn ³⁺ , Ga ³⁺ , Zn ³⁺ , and V ³⁺ And 0 ≦ t ≦ 1,
SiO ₄ ^4- anions are building blocks,
M and T are elements located in octahedral or tetrahedral sites;
p is the stoichiometric coefficient corresponding to P ⁵⁺ located in the silicon tetrahedral site; and 0 <p <1; 0 ≦ x ≦ 2; 1 ≦ m ≦ 2; and x + 2m = 4-p It is.   The electrode material according to claim 1, wherein more than one lithium ion can be extracted or inserted per unit formula.   An electric generator having at least one positive electrode and one negative electrode, characterized in that at least one positive electrode comprises the material of claim 1 and at least one negative electrode is a lithium ion source in high chemical activity . Negative electrode, metal lithium, lithium alloys, composites and insert the lithium into the carbon, or composite obtained by inserting lithium into carbon material in the resulting from the pyrolysis of organic derivatives, a lithium - titanium spinel Li _{1 + y} Ti _{2 -x / 4} O ₄ (where 0 ≦ x ≦ 1, 0 ≦ y ≦ 1) and its solid solution with other spinels, or lithium-transition metal mixed nitrides and mixtures thereof, Item 3. The electricity generator according to Item 3.   4. Electricity generator according to claim 3, characterized in that a conductive additive is present at the positive electrode.   6. The electricity generator according to claim 5, wherein the conductive additive in the positive electrode material is carbon. The positive electrode has the formula Li _λ Fe _f Mn _m Si _s P _p O ₄ (where f + m ≦ 1.2; s + p = 1; 0 ≦ p ≦ 0.6; 8-5p-4s-2m-2f ≧ λ ≧ The electric generator according to claim 3, characterized in that it comprises a material of 8-5p-4s-4m-3f).   4. The electrical generator according to claim 3, wherein the positive electrode contains other intercalation materials in addition to the material of claim 1. Wherein the insert material is a lamellar dichalcogenides, vanadium oxide _{VO x (2.1 ≦ x ≦ 2.5} ) or NASICON (NASICON) similar materials, electricity generating apparatus according to claim 8. The electricity generating device of claim 9, wherein the NASICON-like material is Li ₃ Fe ₂ (PO ₄ ) ₃ .   The electricity generator according to any one of claims 3 to 6, wherein the positive electrode contains a polymerizable binder.   12. Electric generator according to claim 3 or 11, characterized in that the polymerizable binder is a homopolymer or copolymer of tetrafluoroethylene or an ethylene-propylene-diene terpolymer. 13. The electricity generator of claim 12, wherein the positive electrode comprises an aprotic solvent and salt, and the cation is at least partially Li ⁺ .   The electric generator according to claim 3 or 11, wherein the polymerizable binder has ionic conductivity. 14. The electricity generating device according to claim 13, characterized in that the polymerizable binder is a crosslinked or uncrosslinked polyether and dissolves a salt, the cation of which is at least partly Li ⁺ . 12. Electric generator according to claim 11, characterized in that the polymerizable binder swells with an aprotic solvent and contains a salt, the cation of which is at least partly Li ⁺ .   12. The electricity generator according to claim 11, wherein the polymerizable binder is a polymer mainly composed of polyether, polyester or methyl methacrylate, a polymer mainly composed of acrylonitrile, or a polymer mainly composed of vinylidene fluoride.   Aprotic solvent is ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl-ethyl carbonate, γ-butyrolactone, tetraalkylsulfamide, mono-, di-, tri-, tetra- or higher molecular weight of 2000 or less 17. Electric generator according to claim 13 or 16, characterized in that it is a dialkyl ether of oligo-ethylene glycol and mixtures thereof.   A supercapacitor-type electricity generator, characterized in that at least one electrode comprises the material of claim 1.   A variable photoconductive device comprising a transparent semiconductor coated with glass or plastic and two electrodes separated by a solid or gel electrolyte, wherein at least one electrode comprises the material of claim 1 .   21. The variable photoconductive device of claim 20, wherein at least one electrode comprises a thin film layer of the material of claim 1 on a transparent semiconductor coated with glass or plastic.