A negative electrode for a lithium secondary battery, a method for preparing a negative electrode for a lithium secondary battery, and a lithium secondary battery including the negative electrode. The negative electrode for a lithium secondary battery includes a negative electrode current collector layer, a first negative electrode active material layer on one surface or both surfaces of the negative electrode current collector layer, and a second negative electrode active material layer on a surface opposite to a surface of the first negative electrode active material layer facing the negative electrode current collector layer.

Polymer derived ceramic (PDC) materials, compositions and methods of making high capacity, long cycle, long life battery anodes to improve the performance of batteries of all types, including but not limited to coin cell batteries, electric vehicle (EV) batteries, hybrid electric vehicle (HEV) batteries, plug-in hybrid electric vehicle (PHEV) batteries, battery electric vehicle (BEV) batteries, lithium cobalt (LCO) batteries, lithium iron (LFP) batteries; and lithium-ion (Li) batteries, and lead acid batteries. Silicon is incorporated in the PDC material at a molecular level when reacting a polymer derived ceramic precursor and a silicon hydride constituent or a silicon alkoxide constituent to form a PDC composition useful as a powdered battery anode material. A predetermined amount of divinylbenzene is added as a crosslinker and a modifier to increase free carbon content. The resulting battery anode materials increase the specific capacity of a battery measured in milliampere-hours per gram (mAh/g) and increase the life cycle of a battery while minimizing distortion and stress of the anode structure.

A positive electrode active material includes a center portion including a first lithium transition metal oxide with an average composition represented by Formula 1,
Li.sub.1+a1(Ni.sub.b1Co.sub.c1Mn.sub.d1Al.sub.e1M.sup.1.sub.f1)O.sub.2  [Formula 1] wherein, in Formula 1, −0.1≤a1≤0.2, 0.8≤b1<1.0, 0<c1≤0.2, 0<d1≤0.1, 0<e1≤0.05, 0≤f1≤0.05, b1/c1≤25, and b1/d1≥20, and M.sup.1 includes at least one selected from the group consisting of Mg, Ti, Zr, Nb, and W, and a surface portion including a second lithium transition metal oxide with an average composition represented by Formula 2,
Li.sub.1+a2(Ni.sub.b2Co.sub.c2Mn.sub.d2Al.sub.e2M.sup.1.sub.f2)O.sub.2  [Formula 2] wherein, in Formula 2, −0.1≤a2≤0.2, 0.6≤b2≤0.95, 0≤c2≤0.2, 0≤d2≤0.1, 0≤e2≤0.05, 0≤f2≤0.05, b2/c2≤13, and b2/d2≥3, and M.sup.1 includes at least one selected from the group consisting of Mg, Ti, Zr, Nb, and W.

The present invention relates to composite particles containing silicon and carbon, wherein a domain size region of vacancies of 2 nm or less is 44% by volume or more and 70% by volume or less when volume distribution information of domain sizes obtained by fitting a small-angle X-ray scattering spectrum of the composite particles with a spherical model in a carbon-vacancy binary system is accumulated in ascending order, and a true density calculated by dry density measurement by a constant volume expansion method using helium gas is 1.80 g/cm.sup.3 or more and 2.20 g/cm.sup.3 or less.

A cathode for a lithium secondary battery according to embodiments of the present invention includes a cathode current collector, and a cathode active material layer formed on the cathode current collector. The cathode active material layer includes first lithium metal oxide particles each having a secondary particle shape in which primary particles are aggregated and second lithium metal oxide particles each having a single particle shape. A cross-section of the cathode active material layer from an SEM satisfies Equations 1 and 2.

Hybrid electrodes for batteries are disclosed having a protective electrochemically active layer on a metal layer. Other hybrid electrodes include a silicon salt on a metal electrode. The protective layer can be formed directly from the reaction between the metal electrode and a metal salt in a pre-treatment solution and/or from a reaction of the metal salt added in an electrolyte so that the protective layer can be formed in situ during battery formation cycles.

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.

This application provides a positive active material, a positive electrode plate, an electrochemical energy storage apparatus, and an apparatus. The positive active material is Li.sub.xNi.sub.yCo.sub.zM.sub.kMe.sub.pO.sub.rA.sub.m, or Li.sub.xNi.sub.yCo.sub.zM.sub.kMe.sub.pO.sub.rA.sub.m with a coating layer on its surface; and the positive active material is single crystal or quasi-single crystal particles, and a particle size D.sub.n10 of the positive active material satisfies: 0.3 μm≤D.sub.n10≤2 μm. In this application, particle morphology of the positive active material and an amount of micro powder in the positive active material are properly controlled, to effectively reduce side reactions between the positive active material and an electrolyte solution, decrease gas production of the electrochemical energy storage apparatus, and improve storage performance of the electrochemical energy storage apparatus without deteriorating an energy density, cycle performance, and rate performance of the electrochemical energy storage apparatus.

A binder for a secondary battery includes a copolymer having a first repeating unit, a second repeating unit, and a third repeating unit. A ratio of a number of the first repeating unit (A) and a sum of a number of the second repeating unit and a number of the third repeating unit (B) is 90:10 to 52:48. A ratio of the number of the second repeating unit and the number of the third repeating unit is 67:33 to 1:99. A weight average molecular weight of the copolymer is 225,000 to 2,000,000.

Systems and methods for water soluble weak acidic resins as carbon precursors for silicon-dominant anodes may include an electrode coating layer on a current collector, where the electrode coating layer is formed from silicon and pyrolyzed water-soluble acidic polyamide imide as a primary resin carbon precursor. The electrode coating layer may include a pyrolyzed water-based acidic polymer solution additive. The polymer solution additive may include one or more of: polyacrylic acid (PAA) solution, poly (maleic acid, methyl methacrylate/methacrylic acid, butadiene/maleic acid) solutions, and water soluble polyacrylic acid. The electrode coating layer may include conductive additives. The current collector may include a metal foil, where the metal current collector includes one or more of a copper, tungsten, stainless steel, and nickel foil in electrical contact with the electrode coating layer. The electrode coating layer may be more than 70% silicon.