An electrochemical or electric layer system, having at least two electrode layers and at least one ion-conducting layer disposed between two electrode layers. The ion-conducting layer has at least one ion-conducting solid electrolyte and at least one binder at grain boundaries of the at least one ion-conducting solid electrolyte for improving the ion conductivity over the grain boundaries and the adhesion of the layers.

An electrochemical or electric layer system, having at least two electrode layers and at least one ion-conducting layer disposed between two electrode layers. The ion-conducting layer has at least one ion-conducting solid electrolyte and at least one binder at grain boundaries of the at least one ion-conducting solid electrolyte for improving the ion conductivity over the grain boundaries and the adhesion of the layers.

The present invention relates to a cathode active material for a lithium secondary battery comprising: a core including a compound represented by chemical formula 1, and a shell including a compound represented by chemical formula 2, wherein the material composition of the core and the material composition of the shell are different; and a lithium secondary battery including the cathode active material for a lithium secondary battery.

The present invention relates to a cathode active material for a lithium secondary battery comprising: a core including a compound represented by chemical formula 1, and a shell including a compound represented by chemical formula 2, wherein the material composition of the core and the material composition of the shell are different; and a lithium secondary battery including the cathode active material for a lithium secondary battery.

According to the present invention, there are provided processes for preparing a porous composite material comprising a metal and a two-dimensional nanomaterial. In one aspect, the processes comprise the steps of: providing a powder comprising metal particles; heating the powder such that the metal particles fuse to form a porous scaffold; and forming a two-dimensional nanomaterial on a surface of the porous scaffold by chemical vapour deposition (CVD). Also provided are materials obtainable by the present processes, and products comprising said materials.

According to the present invention, there are provided processes for preparing a porous composite material comprising a metal and a two-dimensional nanomaterial. In one aspect, the processes comprise the steps of: providing a powder comprising metal particles; heating the powder such that the metal particles fuse to form a porous scaffold; and forming a two-dimensional nanomaterial on a surface of the porous scaffold by chemical vapour deposition (CVD). Also provided are materials obtainable by the present processes, and products comprising said materials.

The present invention relates to an electrochemical element and a method for producing same, the electrochemical element comprising: electrodes comprising a composite of active material and conductive material having a nanofiber structure; and a cellulose nanofiber separator combined with the electrodes. The electrochemical element according to the present invention obviates the need for separate binder and electrode current collector, has a stable interfacial surface due to the physical union of the separator and electrode, can assure superb mechanical and physical properties, and can maintain stable battery performance even against deformations due to a variety of external impact.

A sulfur-carbon composite including a carbon-based material of which surface is modified by acid treatment is provided, as well as a method for preparing the same, and a lithium-sulfur battery including the same. A sulfur-carbon composite suppresses polysulfide elution when used as a positive electrode active material of a lithium-sulfur battery by including a carbon-based material of which surface is modified to have a hydroxyl group and a carboxyl group capable of adsorbing polysulfide on the surface. Accordingly, capacity property and life time property of the battery may be enhanced. In addition, a surface of the carbon-based material can be modified using a simple process of treating with a mixed solution of nitric acid and sulfuric acid, and a content of functional groups on the surface can be controlled depending on a mixing ratio of the nitric acid and the sulfuric acid.

A sulfur-carbon composite including a carbon-based material of which surface is modified by acid treatment is provided, as well as a method for preparing the same, and a lithium-sulfur battery including the same. A sulfur-carbon composite suppresses polysulfide elution when used as a positive electrode active material of a lithium-sulfur battery by including a carbon-based material of which surface is modified to have a hydroxyl group and a carboxyl group capable of adsorbing polysulfide on the surface. Accordingly, capacity property and life time property of the battery may be enhanced. In addition, a surface of the carbon-based material can be modified using a simple process of treating with a mixed solution of nitric acid and sulfuric acid, and a content of functional groups on the surface can be controlled depending on a mixing ratio of the nitric acid and the sulfuric acid.

Disclosed are electrochemical devices, such as lithium ion battery electrodes, lithium ion conducting solid-state electrolytes, and solid-state lithium ion batteries including these electrodes and solid-state electrolytes. Also disclosed are methods for making such electrochemical devices. In particular, a segmented cell architecture disclosed herein enables solid state batteries to be flexible and capable of assuming a rolled or folded stack structure.