Provided is a negative electrode in which during manufacture thereof a negative electrode paste has an appropriate viscosity, and which is capable of preventing an increase in resistance of a battery when left at a high temperature for a long period of time. A negative electrode disclosed herein includes a negative electrode current collector, and a negative electrode active material layer supported by the negative electrode current collector. The negative electrode active material layer contains a negative electrode active material, and a trace component. The trace component is at least one element selected from the group consisting of Ti, Si, Ca, and Cr. The content of the trace component is not less than 10 mass ppm and not more than 800 mass ppm with respect to the negative electrode active material.

A negative electrode and a secondary battery including the negative electrode, the negative electrode includes a negative electrode active material layer, the negative electrode active material layer includes a negative electrode active material, the negative electrode active material includes a carbon-based negative electrode active material particles. Each carbon-based negative electrode active material particle includes a core comprising a plurality of flake artificial graphite primary particles; natural graphite present on the core; and an amorphous carbon-based material, wherein the natural graphite is present in the carbon-based negative electrode active material particles in an amount of 10 wt % to 30 wt %, and the carbon-based negative electrode active material particles have a sphericity of 0.78 to 0.83.

An active material particle include a lithium silicate composite particle including a lithium silicate phase, and silicon particles dispersed in the lithium silicate phase, and a first coating that covers at least a portion of a surface of the lithium silicate composite particle; wherein the first coating includes an oxide of a first element other than a non-metal element, and a carbon atom, the first coating has a thickness T1.sub.A, an element ratio Rb of the first element relative to the carbon atom at a position of 0.25T1.sub.A of the first coating from the surface of the lithium silicate composite particle, and an element ratio Rt of the first element relative to the carbon atom at a position of 0.75T1.sub.A of the first coating from the surface of the lithium silicate composite particle satisfy Rb>Rt.

The positive electrodes each have a core-body exposed part at which a positive electrode core body is exposed, and a base part in which a composite material layer is formed on at least one surface of the positive electrode core body. The base part has formed therein a first region in which an active material is embedded in the positive electrode core body and a second region in which the the average embedment depth of active material embedded in the positive electrode core body is smaller than that in the first region. The second region is formed adjacent to the core-body exposed part.

Provided is a negative electrode material for a secondary battery capable of improving cycle characteristics due to charge and discharge of the secondary battery. A negative electrode material for a secondary battery includes a negative electrode active material containing a particle 1 and a first carbon material capable of occluding and releasing alkali metal ions or alkaline earth metal ions; and a conductive aid containing a second carbon material different from the first carbon material, in which the particle 1 has a mother particle 2 including a metal or a metal compound, a covering layer 3 covering at least a portion of a surface 2a of the mother particle 2 and including amorphous carbon, and a conductive material 4 attached directly or indirectly to the surface 2a of the mother particle 2 and having conductivity higher than that of the amorphous carbon.

The present disclosure provides a method for forming an ionically conductive polymer composite interlayer. The method may include forming a precursor layer between a first surface of an electroactive material layer and a first surface of a solid-state electrolyte layer and converting the precursor layer to the ionically conductive polymer composite interlayer. The at least one of the electroactive material layer or solid-state electrolyte may include lithium. The first surface of the electroactive material layer and the first surface of the solid-state electrolyte layer may be substantially parallel. The precursor layer may include one or more fluoropolymers comprising carbon and fluorine. The ionically conductive polymer composite layer may have an ionic conductivity greater than or equal to about 1.0×10.sup.−8 S.Math.cm.sup.−1 to less than or equal to about 1.0 S.Math.cm.sup.−1 and may include a lithium fluoride embedded in a carbonaceous matrix.

Silicon-carbon composite materials and related processes are disclosed that overcome the challenges for providing amorphous nano-sized silicon entrained within porous carbon. Compared to other, inferior materials and processes described in the prior art, the materials and processes disclosed herein find superior utility in various applications, including energy storage devices such as lithium ion batteries.

Embodiments described herein relate generally to devices, systems and methods of producing high energy density batteries having a semi-solid cathode that is thicker than the anode. An electrochemical cell can include a positive electrode current collector, a negative electrode current collector and an ion-permeable membrane disposed between the positive electrode current collector and the negative electrode current collector. The ion-permeable membrane is spaced a first distance from the positive electrode current collector and at least partially defines a positive electroactive zone. The ion-permeable membrane is spaced a second distance from the negative electrode current collector and at least partially defines a negative electroactive zone. The second distance is less than the first distance. A semi-solid cathode that includes a suspension of an active material and a conductive material in a non-aqueous liquid electrolyte is disposed in the positive electroactive zone, and an anode is disposed in the negative electroactive zone.

An immobilized selenium body, made from carbon and selenium and optionally sulfur, makes selenium more stable, requiring a higher temperature or an increase in kinetic energy for selenium to escape from the immobilized selenium body and enter a gas system, as compared to selenium alone. Immobilized selenium localized in a carbon skeleton can be utilized in a rechargeable battery. Immobilization of the selenium can impart compression stress on both the carbon skeleton and the selenium. Such compression stress enhances the electrical conductivity in the carbon skeleton and among the selenium particles and creates an interface for electrons to be delivered and or harvested in use of the battery. A rechargeable battery made from immobilized selenium can be charged or discharged at a faster rate over conventional batteries and can demonstrate excellent cycling stability.

A negative electrode material for a lithium-ion secondary battery includes composite particles, each of the composite particles having a structure in which plural flat graphite particles are stacked, wherein the composite particles have a particle size distribution D90/D10 of from 2.0 to 5.0, or wherein the plural flat graphite particles have a particle size distribution D90/D10 of from 2.0 to 4.4.