A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The separator includes a substrate layer and a surface layer formed on at least one principal plane of the substrate layer, the surface layer contains polyvinylidene fluoride and an inorganic material particle, and an amount of deformation against pressure of the surface layer is larger than that of the substrate layer.

Cathodes for a fast charging lithium ion battery, processes for manufacturing thereof and corresponding batteries are provided. Cathode formulations comprise cathode material having an olivine-based structure, binder material, and monomer material selected to polymerize into a conductive polymer upon partial delithiation of the cathode material during at least a first charging cycle of a cell having a cathode made of the cathode formulation. When the cathode is used in a battery, polymerization is induced in-situ (in-cell) during first charging cycle(s) of the battery to provide a polymer matrix which is evenly dispersed throughout the cathode.

A lithium ion secondary battery has, as a positive electrode active material into and from which lithium ions can be intercalated and deintercalated, a lithium oxide represented by Formula Li(1+y)CoPO.sub.4X(y) (in the formula, X is selected from the group consisting of F, Cl, Br and I, and y lies in the range of 1<y≤2).

The present invention is a lithium-phosphorus-based composite oxide/carbon composite used for a positive electrode active material of an electrochemical device, including lithium-phosphorus-based composite oxide with the surface being coated with carbon, wherein the lithium-phosphorus-based composite oxide/carbon composite has elutable fluoride ions, which are eluted to an elute from the composite dispersed to ultrapure water, in a mass ratio of 500 ppm or more and 15000 ppm or less in comparison with the lithium-phosphorus-based composite oxide/carbon composite, and the lithium-phosphorus-based composite oxide has a composition of the following general formula (1):

Li.sub.1-xFe.sub.1-zM.sub.zPO.sub.4-aF.sub.a(−0.1≦x<1,0≦z≦1,0≦a≦4)  (1)

(wherein, M represents one or more kinds of metal element selected from the group of Mn, Ni, Co, V, Cr, Al, Nb, Ti, Cu, and Zn). This provides a lithium-phosphorus-based composite oxide/carbon composite that gives higher charge/discharge capacity when it is used as a positive electrode active material of an electrochemical device even though a trivalent-containing raw material is used.

A positive electrode plate may include a current collector, a first positive electrode active material layer and a second positive electrode active material layer. The first positive electrode active material layer may comprise a first positive electrode active material, a first binder and a first conductive agent; the second positive electrode active material layer may comprise a second positive electrode active material, a second binder and a second conductive agent. The second positive electrode active material may be selected from carbon-coated Li.sub.βFe.sub.αM.sub.(1−α)PO.sub.4, and the second positive electrode active material may have a diffraction peak A between 29° and 30° in the X-ray diffraction pattern, and a diffraction peak B between 25° and 26°, and the intensity ratio I.sub.A/I.sub.B of the diffraction peaks may satisfy: 0.98≤I.sub.A/I.sub.B≤1.1.

The electrical resistance of active cathodic and anodic films may be significantly reduced by the addition of small fractions of conductive additives within a battery system. The decrease in resistance in the cathode and/or anode leads to easier electron transport through the battery, resulting in increases in power, capacity and rates while decreasing joules heating losses.

The electrical resistance of active cathodic and anodic films may be significantly reduced by the addition of small fractions of conductive additives within a battery system. The decrease in resistance in the cathode and/or anode leads to easier electron transport through the battery, resulting in increases in power, capacity and rates while decreasing joules heating losses.

The electrical resistance of active cathodic and anodic films may be significantly reduced by the addition of small fractions of conductive additives within a battery system. The decrease in resistance in the cathode and/or anode leads to easier electron transport through the battery, resulting in increases in power, capacity and rates while decreasing joules heating losses.

The electrical resistance of active cathodic and anodic films may be significantly reduced by the addition of small fractions of conductive additives within a battery system. The decrease in resistance in the cathode and/or anode leads to easier electron transport through the battery, resulting in increases in power, capacity and rates while decreasing joules heating losses.

A battery includes a fluid negative electrode and a fluid positive electrode separated by a solid electrolyte at least when the electrodes and electrolyte are at an operating temperature. The solid electrolyte includes ions of the negative electrode material forming the fluid negative electrode and has a softness less than beta-alumina solid electrolyte (BASE) ceramics. In one example, the fluid negative electrode comprises lithium (Li), the fluid positive electrode comprises sulfur (S) and the solid electrolyte comprises lithium iodide (LiI).