α-Phase manganese dioxide, when in a mesoporous form, has useful properties enabling its use as electrodes, inter alia, in lithium batteries and supercapacitors.
Mesoporous electrode materials with large particle size where the majority of particles have sizes in excess of 15 μm have a well connected internal mesopore network, and have high power capability when used as intercalation materials for a range of battery and supercapacitor chemistries that rely on intercalation mechanisms to store charge.
H01M 4/48 - Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
H01M 4/50 - Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
H01M 4/52 - Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
H01M 4/58 - Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFySelection of substances as active materials, active masses, active liquids of polyanionic structures, e.g. phosphates, silicates or borates
Relatively disordered mesoporous particulate materials have internal porosity, a surface area of 100 m2/g or greater with a network of pores characterised by a peak in the pore size distribution at a value between 2 and 20 nm and a ratio of the half-height width of the distribution's peak to the pore diameter axis position of the peak of at least 0.6.
A metal such as tin which it is difficult to prepare from its salt by- reduction in a liquid crystal system may more rea'dily be obtained if the reduction is carried out in the presence of a compound of a second metal, such as copper, where the compound of the second metal is more readily reduced by the reducing agent such as sodium hypophosphite than is the salt of the first-mentioned metal.
B22F 9/24 - Making metallic powder or suspensions thereofApparatus or devices specially adapted therefor using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
An electrochemical cell for a smart is compressible under a pressure not exceeding 4.5 MegaPascal to reduce reversibly its thickness by at least 5% and has at least two external surfaces (3, 4), electrically insulated from each other, which are electrically conducting and are, or are in electrical contact with, respective electrodes (1, 2).
A lithium ion electrochemical cell comprises a positive electrode, a negative electrode and a non-aqueous electrolyte. The negative electrode comprises a powder of a mesoporous material capable of forming a lithium insertion alloy in contact with a support, the powder being chemically deposited from a liquid crystal phase.
An electrochemical cell has a negative electrode comprising a liquid crystal templated mesoporous material capable of forming a lithium insertion alloy, and having a relatively high porosity of from 38% to 80%.
A hybrid supercapacitor comprises a double layer electrode and a redox electrode, in which the ratio of the volumes, and hence the thicknesses, of the two electrodes (the double layer electrode and the redox electrode) is significantly higher than previously considered optimum, specifically from 9:1 to 100:1. The active material is a mesoporous structurewith a periodic arrangement of pores having a defined recognisable topology and architecture. The mesoporous material of the electrodes may be prepared by a liquid crystal templating.
When depositing a metal or a compound of the metal from a liquid crystal phase comprising a metal compound, e.g. a metal salt, by electrochemical means, high concentrations of the salt may be employed by using an ionic surfactant in place of the commonly used non-ionic surfactant.
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