A method for the synthesis of compounds of the formula C--Li.sub.xM.sub.1-yM'.sub.y(XO.sub.4).sub.n, where C represents carbon cross-linked with the compound Li.sub.xM.sub.1-yM'.sub.y(XO.sub.4).sub.n, in which x, y and n are numbers such as 0.ltoreq.x.ltoreq.2, 0.ltoreq.y.ltoreq.0.6, and 1.ltoreq.n.ltoreq.1.5, M is a transition metal or a mixture of transition metals from the first period of the periodic table, M' is an element with fixed valency selected among Mg.sup.2+, Ca.sup.2+, Al.sup.3+, Zn.sup.2+ or a combination of these same elements and X is chosen among S, P and Si, by bringing into equilibrium, in the required proportions, the mixture of precursors, with a gaseous atmosphere, the synthesis taking place by reaction and bringing into equilibrium, in the required proportions, the mixture of the precursors, the procedure comprising at least one pyrolysis step of the carbon source compound in such a way as to obtain a compound in which the electronic conductivity measured on a sample of powder compressed at a pressure of 3750 Kgcm.sup.-2 is greater than 10.sup.-8 Scm.sup.-1. The materials obtained have excellent electrical conductivity, as well a very improved chemical activity.

A composition for applying a coating on a support at low temperature from a dispersion of at least a component of the coating to be deposited in the composition. The composition includes at least a strong and heavy solvent with a boiling point higher than 150.degree. C. approximately, and a weak solvent with a boiling point less than 100.degree. C. approximately. The solvents forming the composition must constitute a mixture that evaporates at a temperature less than 100.degree. C. The composition is particularly useful for forming electrodes or electrolyte in lithium-ion batteries. The method and the device used for forming the coating use a dispersion spreader and an infrared lamp.

The present invention is concerned with cross-linked sulfonated polymers, eventually perfluorinated, and their preparation process. When molded in the form of membranes, the polymers are useful in electrochemical cells, in a chlorine-sodium electrolysis process, as separator in an electrochemical preparation or organic and inorganic compounds, as separators between an aqueous phase and an organic phase, or as catalyst for Diels-Alder additions, Friedel-Craft reactions, aldol concentrations, cationic polymerisation, esterification, and acetal formation.

A breaking detector for a shear pin having a central bore, comprises an electrically conductive element forming an elongated loop extending on a length of the bore of the shear pin and having upper ends defining contact surfaces adjacent to each other. An electrically insulating element extends in the loop, to prevent the conductive element from short-circuiting. Power supply cables are connected respectively to the contact surfaces and are provided with connectors facilitating connection of the breaking detector to other breaking detectors or to an alarm panel. An electrically insulating body removably supports the elements of the detector in the bore of the shear pin. An identification circuit having a light indicator connected between the contact surfaces and projecting at an upper end of the body allows to locate a defective shear pin having broken the conductive element.

The low stray interconnecton power converting module is for converting a DC voltage into an AC voltage. It comprises two DC voltage terminals for receiving the DC voltage, an AC voltage terminal for delivering the AC voltage, and a half-bridge including a pair of power switching elements connected as a series totem pole between the DC voltage terminals via the AC voltage terminal. It also comprises a decoupling device for decoupling the half-bridge. The decoupling device comprises a series of at least two adjacent superimposed electrode plates separated by a dielectric material and extending proximately in overlapping relation with the half-bridge. Each of the adjacent electrode plates is connected to a different one of the DC terminals. The electrode plates form with the two power switching elements, the DC terminals and the AC terminal, a reduced cross section belt-like current closed loop by which a low stray interconnection inductance power converting module is obtained.