Abstract: A negative active material, a lithium battery including the negative active material, and a method of preparing the negative active material. The negative active material includes a silicon-based alloy including Si, Al, and Fe. The silicon-based alloy includes an active phase of silicon nanoparticles and an inactive phase of Si3Al3Fe2 and Si2Fe in a ratios suitable to improve the lifespan of the lithium battery.

Abstract: An electrode for a lithium secondary battery including a silicon-based alloy having an expansion coefficient of 10% or greater and an electrochemically inactive whisker, and a lithium secondary battery using the electrode for a lithium secondary battery.

Abstract: In an aspect, an electrode active material for a lithium secondary battery, the electrode active material including a silicon-based alloy and a coating film containing a polymer that includes a 3,4-ethylenedioxythiophene repeating unit and an oxyalkylene repeating unit, coated on the surface of the silicon-based alloy are provided.

Abstract: A composite anode active material, an anode including the composite anode active material, a lithium battery including the anode, and a method of preparing the composite anode active material, the composite anode active material including a core including a ternary alloy, the ternary alloy being capable of intercalating and deintercalating lithium; and a carbonaceous coating layer on the core.

Abstract: An anode active material, a lithium battery including the anode active material, and a method of preparing the anode active material are provided. The anode active material includes an alloy containing silicon (Si), titanium (Ti) and nickel (Ni) elements, wherein the alloy includes a Si phase and an alloy phase, and a peak intensity ratio (I(111)/I(220)) of Si(111) to Si(220) plane in a X-ray diffraction spectrum of the Si phase is from about 1.0 to about 1.5.

Abstract: A silicon-based negative active material that includes a core including silicon oxide represented by SiOx (0<x<2); and a coating layer including metal oxide, and the metal of the metal oxide includes aluminum (Al), titanium (Ti), cobalt (Co), magnesium (Mg), calcium (Ca), potassium (K), sodium (Na), boron (B), strontium (Sr), barium (Ba), manganese (Mn), nickel (Ni), vanadium (V), iron (Fe), copper (Cu), phosphorus (P), scandium (Sc), zirconium (Zr), niobium (Nb), chromium (Cr), and/or molybdenum (Mo), the core has a concentration gradient where an atom % concentration of a silicon (Si) element decreases to the center of the core, and an atom % concentration of an oxygen (O) element increases to the center, and a depth from the surface contacting the coating layer where a concentration of the silicon (Si) element is about 55 atom % corresponds to about 2% to about 20% of a diameter of the core.

Abstract: In an aspect, a negative active material for a rechargeable lithium battery including surface modified silicon oxide particles is disclosed.

Abstract: According to an embodiment of the present invention, a negative active material for a rechargeable lithium battery includes silicon oxide particles represented by SiOx (where 0<x<2) in which an atom % of a silicon phase decreases in a concentration gradient according to a depth from the surface of each particle to the center of the particle, and has an atom % of an O phase that increases in a concentration gradient. In the atom % concentration graph of the silicon (Si) phase according to the depth, the integral value of the atom % concentration of the silicon (Si) phase from the surface (where the depth is 0) to a depth where the concentration of the silicon (Si) phase is 55 atom % is about 5000 to about 40000 nm·atom %.

Abstract: A negative active material for a rechargeable lithium battery includes a core including a SiO2 matrix and a Si grain, and a coating layer continuously or discontinuously coated on the core. The coating layer includes SiC and C, and the peak area ratio of the SiC (111) plane to the Si (111) plane as measured by X-ray diffraction analysis (XRD) using a CuK? ray ranges from about 0.01 to about 0.5.

Abstract: Disclosed is a rechargeable lithium battery that includes a positive electrode including a lithium nickel-based positive active material; a negative electrode including a negative active material; an electrolyte including a lithium salt and a non-aqueous organic solvent; and a separator including a polymer substrate and a hydroxide compound-containing coating layer disposed on the polymer substrate.

Abstract: Disclosed is a rechargeable lithium battery that includes a positive electrode including a lithium nickel-based positive active material; a negative electrode including a negative active material; an electrolyte including a lithium salt and a non-aqueous organic solvent; and a separator including a polymer substrate and a hydroxide compound-containing coating layer disposed on the polymer substrate.

Abstract: Disclosed is a rechargeable lithium battery that includes a positive electrode including a positive active material, a negative electrode including a silicon-based negative active material, an electrolyte including a lithium salt and a non-aqueous organic solvent, and a separator including a polymer substrate and a ceramic-containing coating layer on the polymer substrate. The ceramic-containing coating layer has a porosity at or between about 50% and about 90%, and a thickness at or between about 2 ?m and about 6 ?m. The rechargeable lithium battery has a capacity per volume of more than or equal to about 700 Wh/l.

Abstract: Disclosed is a rechargeable lithium battery that includes a positive electrode including a positive active material, a negative electrode including a silicon-based negative active material, an electrolyte including a lithium salt and a non-aqueous organic solvent, and a separator including a polymer substrate and a ceramic-containing coating layer on the polymer substrate. The ceramic-containing coating layer has a porosity at or between about 50% and about 90%, and a thickness at or between about 2 ?m and about 6 ?m. The rechargeable lithium battery has a capacity per volume of more than or equal to about 700 Wh/l.

Abstract: Disclosed is a rechargeable lithium battery that includes a positive electrode including a lithium nickel-based positive active material; a negative electrode including a negative active material; an electrolyte including a lithium salt and a non-aqueous organic solvent; and a separator including a polymer substrate and a hydroxide compound-containing coating layer disposed on the polymer substrate.