摘要:
The invention concerns a method for producing a multilayer material based on active lithium, consisting of the deposition of an active lithium film on a protection layer with a sufficient speed to substantially avoid oxidation of the lithium and/ or over a sufficient period such that the adhesion of the lithium occurs upon contact with the protection layer. A multilayer material of the invention presents excellent impedance stability and absence of dendrite formation after the cycling process, when incorporated into an electrochemical battery as anode. The batteries, the anode of which is composed of a multilayer material of the invention are particularly efficient with respect to their coulombic efficiency.
摘要:
The invention concerns a synthesis method for a material consisting of particles comprising a core and a coating and/or being interconnected by a carbon cross-linkage, the core of said particles including at least a compound of formula LixM1-yM'y(XO4)n wherein: x, y and n are numbers such that 0≤ x ≤2, 0 ≤ y ≤0.6 and 1 ≤ n ≤1.5; M is a transition metal; M' is a element of fixed valency, and the synthesis being performed by reacting and balancing the mixture of precursors, with a reducing gas atmosphere, so as to bring the transition metal(s) to the desired degree of valency, the synthesis being carried out in the presence of a carbon source called conductive carbon which is pyrolyzed. The resulting materials exhibit excellent electrical conductivity and a highly enhanced chemical activity. M' can be selected among Mg?2+, Ca2+ Al3+, Zn2+¿ or a combination of those elements, X is selected among S, P, and Si. Said material can be used as active electrode material in batteries.
摘要:
The invention concerns the physical or chemical purification of natural graphite ore. Said purification is preferably applied to the surface of natural graphite to enable the formation of a passivation film during the first discharge or parting of lithium in the graphite when the latter is used in a lithium-ion cell. Grinding to a small size before purification enables to optimise particle distribution, resulting in a more homogeneous electrode. Said grinding is carried out in the presence of natural graphite impurities which act as micro-abrasive and provide the graphite with hardness thereby enhancing its mechanical properties.