A negative electrode active material includes a silicon-containing alloy having a composition represented by: Si.sub.xSn.sub.yM.sub.zA.sub.a (A is unavoidable impurities, M is one or more transition metal elements, x, y, z, and a represent values of percent by mass, and 0<x<100, 0<y<100, 0<z<100, and 0≦a <0.5 and x+y+z+a=100). The silicon-containing alloy has a lattice image subjected to Fourier transform processing to obtain a diffraction pattern and a size determined as an average value of maximum five major axis diameters of regions having a periodic array from a Fourier image obtained by subjecting a diffraction ring portion present in a width of from 0.7 to 1.0 when a distance between Si regular tetrahedrons is 1.0 in this diffraction pattern to inverse Fourier transform is 10 nm or less.

This disclosure relates to an SO.sub.2-based electrolyte for a rechargeable battery cell containing at least one conducting salt of the Formula (I) ##STR00001##
wherein M is a metal selected from the group consisting of alkali metals, alkaline earth metals, metals of group 12 of the periodic table of the elements and aluminum; x is an integer from 1 to 3; the substituents R, R.sup.2, R.sup.3 and R.sup.4 are each independently selected from the group consisting of C.sub.1-C.sub.10 alkyl, C.sub.2-C.sub.1 alkenyl, C.sub.2-C.sub.1 alkynyl, C.sub.3-C.sub.10 cycloalkyl, C.sub.6-C.sub.14 aryl, and C.sub.5-C.sub.14 heteroaryl; and Z is aluminum or boron.

The present invention provides an anode active material and a method for preparing the same, wherein the anode active material has a core-shell structure having formula (MOx-Liy)-C (here, M is a metal (or metalloid), x is greater than 0 and less than 1.5, and y is greater than 0 and less than 4) and including a core part containing an alloy of a metal (or metalloid) oxide-Li (MOx-Liy) and a shell part containing a carbon material coated on a surface of the core part, wherein the shell part contains lithium in an amount less than 5 atm % in the surface and the inner portion thereof. The anode active material can provide high capacity, excellent cycle characteristics, excellent volume expansion control capability, and high initial efficiency.

A metal-ion battery cell is provided that comprises anode and cathode electrodes, a separator, and an electrolyte. The anode electrode may, for example, have a capacity loading in the range of about 2 mAh/cm2 to about 10 mAh/cm2 and comprise anode particles that (i) have an average particle size in the range of about 0.2 microns to about 40 microns, (ii) exhibit a volume expansion in the range of about 8 vol. % to about 180 vol. % during one or more charge-discharge cycles of the battery cell, and (iii) exhibit a specific capacity in the range of about 600 mAh/g to about 2600 mAh/g. The electrolyte may comprise, for example, (i) one or more metal-ion salts and (ii) a solvent composition that comprises one or more low-melting point solvents that each have a melting point below about −70° C. and a boiling point above about +70° C.

Systems and methods for water based phenolic binders for silicon-dominant anodes may include an electrode coating layer on a current collector, where the electrode coating layer is formed from silicon and a pyrolyzed water-based phenolic binder. The water-based phenolic binder may include phenolic/resol type polymers crosslinked with poly(methyl vinyl ether-alt-maleic anhydride), poly(methyl vinyl ether-alt-maleic acid), and/or Poly(acrylamide-co-diallyldimethylammonium chloride) (PDADAM). The electrode coating layer may further include conductive additives. The current collector may comprise 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 include more than 70% silicon. The electrode may be in electrical and physical contact with an electrolyte, where the electrolyte includes a liquid, solid, or gel. The battery electrode may be in a lithium ion battery.

This invention relates to particulate electroactive materials consisting of a plurality of composite particles, wherein the composite particles comprise a plurality of silicon nanoparticles dispersed within a conductive carbon matrix. The particulate material comprises 40 to 65 wt % silicon, at least 6 wt % and less than 20% oxygen, and has a weight ratio of the total amount of oxygen and nitrogen to silicon in the range of from 0.1 to 0.45 and a weight ratio of carbon to silicon in the range of from 0.1 to 1. The particulate electroactive materials are useful as an active component of an anode in a metal ion battery.

Electrolyte additives for energy storage devices comprising functional epoxides compounds are disclosed. Catalysts may be combined with the functional epoxides to create bi-component electrolyte additive systems, which can be utilized as additives to an electrolyte composition. The energy storage device may comprise a first electrode and a second electrode, wherein at least one of the first electrode and the second electrode is a Si-based electrode, a separator between the first electrode and the second electrode, and an electrolyte composition.

A lithium-ion cell includes a ribbon-shaped electrode-separator assembly having an anode, a separator, and a cathode in a sequence anode/separator/cathode. The anode has a ribbon-shaped anode current collector having a first longitudinal edge, a second longitudinal edge, and two ends, wherein the anode current collector has a strip-shaped main region loaded with a layer of negative electrode material and a free edge strip extending along the first longitudinal edge that is not loaded with the electrode material. The cathode has a ribbon-shaped cathode current collector, wherein the cathode current collector has a strip-shaped main region loaded with a layer of positive electrode material and a free edge strip extending along the first longitudinal edge that is not loaded with the electrode material. The negative electrode material containing the at least one active material in a range of from 20 wt % to 90 wt %.

An electrochemical cell comprises an anode, a cathode and an electrolyte composition, wherein the anode comprises as anode active material a combination of at least a carbon material and a silicon material; and the electrolyte composition comprises a solvent, from 0.5 wt. % to 70 wt. %, based on the total weight of the electrolyte, of a fluorinated acyclic carboxylic acid ester compound, from 0.5 wt. % 10 wt. %, based on the total weight of the electrolyte, of a fluorinated cyclic carbonate compound; and an electrolyte salt.

An embodiment of the present invention relates to a silicon-based carbon composite, a preparation method therefor, and an anode active material for a lithium secondary battery, comprising same, and, more specifically, the silicon-based carbon composite of the present invention is a silicon-based carbon composite having a core-shell structure, wherein the core comprises silicon, silicon oxide compound and magnesium silicate, the shell comprises at least two carbon layers comprising a first carbon layer and a second carbon layer, and the second carbon layer is reduced graphene oxide, and thus, during application of the silicon-based carbon composite to an anode active material for a secondary battery, the charge/discharge capacity, initial charge/discharge efficiency and capacity retention of the secondary battery can be improved.