Abstract: Disclosed are a system and method for automatically evaluating an essay. The system includes a structure analysis module configured to divide learning data and learner essay text in a predetermined structure analysis unit, generate structure tagging information for each structure analysis unit, and structure the learning data and the learner essay text by attaching the structure tagging information to the learning data and the learner essay text, a learning module configured to generate an essay evaluation model through learning by using essay text that is included in the structured learning data and the structure tagging information as an input value and using an evaluation score that is included in the structured learning data as a label, and an evaluation module configured to generate essay evaluation results using the essay evaluation model.

Abstract: An electrode including a current collector; and an electrode active material layer disposed on at least one surface of the current collector is disclosed. The electrode active material layer includes a lower layer region facing the current collector, and an upper layer region facing the lower layer region and extended to the surface of the electrode active material layer. The lower layer region includes a first active material and a first non-rubbery binder and is free from a rubbery binder. The upper layer region includes a second active material, a second non-rubbery binder, and a rubbery binder. The rubbery binder is a hydrogenated nitrile butadiene rubber (H-NBR). Each of the first non-rubbery binder and the second non-rubbery binder includes a polyvinylidene fluoride (PVDF)-based polymer, and the weight ratio of the second non-rubbery binder to the rubbery binder in the upper layer region is 1:0.03-1:0.07.

Abstract: A lithium secondary battery includes a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode includes a positive electrode active material layer having a positive electrode active material containing an overlithiated manganese-based oxide represented by Formula 1 below, and the negative electrode includes a negative electrode active material layer having a silicon-based negative electrode active material, LiaNibCocMndMeO2 ??[Formula 1] wherein, M is at least one selected from the group consisting of Al, B, Co, W, Mg, V, Ti, Zn, Ga, In, Ru, Nb, Sn, Sr, and Zr, and 1<a, 0?b?0.5, 0?c?0.1, 0.5?d<1.0, and 0?e?0.2, and. Preferably, in the Formula 1, 1.1?a?1.5, 0.1?b?0.4, 0?c?0.05, 0.5?d?0.80, and 0?e?0.1.

Abstract: An electrode including a current collector; and an electrode active material layer disposed on at least one surface of the current collector is disclosed. The electrode active material layer includes a lower layer region facing the current collector, and an upper layer region facing the lower layer region and extended to the surface of the electrode active material layer. The lower layer region includes a first active material and a first non-rubbery binder and is free from a rubbery binder. The upper layer region includes a second active material, a second non-rubbery binder, and a rubbery binder. The rubbery binder is a hydrogenated nitrile butadiene rubber (H-NBR). Each of the first non-rubbery binder and the second non-rubbery binder includes a polyvinylidene fluoride (PVDF)-based polymer, and the weight ratio of the second non-rubbery binder to the rubbery binder in the upper layer region is 1:0.03-1:0.07.

Abstract: A negative electrode active material that includes an active material core that allows the intercalation and deintercalation of lithium ions; and a conductive material that is attached to a surface of the active material core through an organic linker. The conductive material includes at least one selected from the group consisting of a linear conductive material and a planar conductive material. The organic linker is a compound that includes a hydrophobic structure and a substituent including a polar functional group.

Abstract: A composite electrode comprising a charge-conducting material, a charge-providing material bound to the charge-conducting material, and a plurality of single-walled carbon nanotubes bound to a surface of the charge-providing material. High-capacity electroactive materials that assure high performance are a prerequisite for ubiquitous adoption of technologies that require high energy/power density lithium (Li)-ion batteries, such as smart Internet of Things (IoT) devices and electric vehicles (EVs). Improved electrode performance and lifetimes are desirable. The disclosed electrode can have a Coulombic efficiency of 99% or greater, and a stable capacity retention after 100 cycles or more. Methods of making a composite electrode are disclosed.

Abstract: Disclosed herein is a composite electrode comprising a charge-conducting material, a charge-providing material bound to the charge-conducting material, and a plurality of single-walled carbon nanotubes bound to a surface of the charge-providing material. High-capacity electroactive materials that assure high performance are a prerequisite for ubiquitous adoption of technologies that require high energy/power density lithium (Li)-ion batteries, such as smart Internet of Things (IoT) devices and electric vehicles (EVs). Improved electrode performance and lifetimes are desirable. The disclosed electrode can have a Coulombic efficiency of 99% or greater, and a stable capacity retention after 100 cycles or more. Also disclosed herein are methods of making a composite electrode.

Abstract: The present technology relates to a method of manufacturing a negative electrode, and the method includes: manufacturing a negative electrode having a negative electrode active material layer formed thereon by coating a negative electrode slurry including a negative electrode active material at least on one surface of a current collector; pre-lithiating the negative electrode; and forming an inorganic coating layer on a surface of the negative electrode active material layer by aging the pre-lithiated negative electrode under an CO2 atmosphere.

Abstract: The present invention relates to a three-dimensional structure electrode, a method for manufacturing same, and an electrochemical element including the electrode. The present invention is characterized by comprising: (a) an upper conductive layer and a lower conductive layer which have a structure constituting an assembly within which a conductive material and a porous nonwoven fabric including a plurality of polymeric fibers are three-dimensionally connected in an irregular and continuous manner, thereby forming a mutually connected porous structure; and (b) an active material layer forming the same assembly structure as the conductive layers and forming a three-dimensionally filled structure in which electrode active material particles are uniformly filled inside the mutually connected porous structure formed in the assembly structure, wherein the active material layer is formed between the upper conductive layer and the lower conductive layer.

Abstract: An activation method for a lithium secondary battery, and a lithium secondary battery manufactured using the same are disclosed herein. In some embodiments, the method comprises charging a secondary battery, wherein the secondary battery includes a positive electrode having a sacrificial positive electrode material represented by Formula 1 and having an orthorhombic structure, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte solution, and then holding the secondary battery for a predetermined period of time at a voltage of 3.2 V or greater.

Abstract: The present invention relates to a three-dimensional structure electrode, a method for manufacturing same, and an electrochemical element including the electrode. The present invention is characterized by comprising: (a) an upper conductive layer and a lower conductive layer which have a structure constituting an assembly within which a conductive material and a porous nonwoven fabric including a plurality of polymeric fibers are three-dimensionally connected in an irregular and continuous manner, thereby forming a mutually connected porous structure; and (b) an active material layer forming the same assembly structure as the conductive layers and forming a three-dimensionally filled structure in which electrode active material particles are uniformly filled inside the mutually connected porous structure formed in the assembly structure, wherein the active material layer is formed between the upper conductive layer and the lower conductive layer.

Abstract: A rolling method for an electrode, the method comprising the steps of: coating an electrode slurry including an electrode active material, on a current collector, to form an electrode specimen; measuring rheological properties of the electrode specimen according to temperature; deriving an appropriate temperature condition for rolling the electrode from the rheological properties of the electrode specimen according to temperature; and rolling the electrode in the appropriate temperature condition.

Abstract: Disclosed is a binder composition for a negative electrode which includes a binder polymer containing at least one first functional group selected from the group consisting of a hydroxy group and a carboxyl group, and a crosslinked polymer containing at least one second functional group selected from the group consisting of an amino group and an isocyanate group, wherein the crosslinked polymer is present in an amount of 1.5 parts by weight to 8.5 parts by weight based on 100 parts by weight of the binder polymer.

Abstract: The present invention relates to an anode including multiple current collectors juxtaposed in parallel, and a secondary battery comprising same, wherein the anode enables providing a high-capacity secondary battery while suppressing volume changes due to a silicone component-containing active material employed therein.

Abstract: A negative electrode active material that includes active material core particles that allow the intercalation and deintercalation of lithium ions; a conductive material disposed on a surface of each active material core particle; an organic linker that connects the active material core particles and the conductive material; and an elastomer that covers at least a part of the active material core particles and the conductive material. The conductive material includes at least one selected from the group consisting of a linear conductive material and a planar conductive material, and the organic linker is a compound that includes a hydrophobic structure and a substituent including a polar functional group.

Abstract: A negative electrode active material that includes an active material core that allows the intercalation and deintercalation of lithium ions; and a conductive material that is attached to a surface of the active material core through an organic linker. The conductive material includes at least one selected from the group consisting of a linear conductive material and a planar conductive material. The organic linker is a compound that includes a hydrophobic structure and a substituent including a polar functional group.

Abstract: A negative electrode active material that includes an active material core that allows for the intercalation and deintercalation of lithium ions. The negative electrode active material also includes a plurality of conductive materials positioned on a surface of the active material core, a plurality of organic linkers each including a hydrophobic group and a polar functional group bonded to the hydrophobic group, and an elastic unit. The elastic unit includes an elastic moiety having two or more binding sites, and a functional group bonded to a binding site of the elastic moiety. The functional group reacts with the polar functional group of the organic linker, and one or more of the plurality of organic linkers are connected to the conductive materials through the hydrophobic groups of the organic linkers.

Abstract: A flexible electrode includes: a current collector; an electrode layer positioned at a top of the current collector; a first support layer positioned at a top of the electrode layer; and a second support layer positioned at a bottom of the current collector, wherein each of the first support layer and the second support layer is a conductive coating layer-containing porous polymer substrate including a porous polymer substrate, and a conductive coating layer positioned on a surface of the porous polymer substrate and including a conductive material and a dispersing agent, and the porous polymer substrate is a non-woven web provided with a plurality of polymer fibers and a pore structure interconnected by the plurality of polymer fibers.

Abstract: Provided are a film for covering an entire outer surface of a secondary battery electrode assembly and a method for manufacturing the same, wherein the film comprises a mechanical support layer, a reduced graphene oxide layer disposed on an outer surface of the mechanical support layer, and a sealant layer disposed on an outer surface of the reduced graphene oxide layer, wherein reduced graphene oxide sheets of the reduced graphene oxide layer form electrostatic interaction between adjacent ones of the reduced graphene oxide sheets.

Abstract: A packaging for a flexible secondary battery improves the vapor barrier performance and flexibility of the flexible secondary battery. The packaging is in a shape of a tube that is wrapped around an outer surface of an electrode assembly, and includes a mechanical support layer; a reduced graphene oxide layer disposed on the mechanical support layer and including a plurality of reduced graphene oxide sheets; a heat shrink layer disposed on the reduced graphene oxide layer; and a sealant layer disposed on the heat shrink layer, wherein the plurality of reduced graphene oxide sheets in the reduced graphene oxide layer forms electrostatic interaction between adjacent sheets of the plurality of reduced graphene oxide sheets. A flexible secondary battery including the packaging is also provided.