An electrolyte for use in an energy storage device, an energy storage device and a method of forming such electrolyte. The electrolyte includes a polymer matrix of at least two crosslinked structures, including a first polymeric material and a second polymeric material; and an electrolytic solution retained by the polymer matrix; wherein the electrolyte is arranged to physically deform when subjected to an external mechanical load applied to the polymer matrix.

Electrolytes and electrolyte additives for energy storage devices comprising functional thiophene compounds are disclosed. The energy storage device comprises 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, an electrolyte, and at least one electrolyte additive selected from a thiophene compound.

A nonaqueous electrolyte composition for use in a redox flow battery system, comprising: a nonaqueous supporting electrolyte; and a metal ligand complex of formula II: ##STR00001##
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.6 are each independently H, halogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy, aryloxy, substituted aryloxy, heteroaryloxy, substituted heteroaryloxy, or a polyether, ##STR00002##
wherein R.sub.5 is H, alkyl, or substituted alkyl; and M is a transition metal or zinc.

The invention relates to the technical field of secondary batteries, specifically to a high-temperature lithium secondary battery electrolyte and a battery cell. The high-temperature lithium secondary battery contains an additive composition consisting of a diisocyanate compound and a bicyclic sulfate compound.

Batteries and battery cells are described including batteries and battery cells having solid-state components such as porous and/or dense solid state components. Aspects of dimensions, porosity and pore structure are also described.

This invention provides nonaqueous electrolyte solutions for lithium batteries. The nonaqueous electrolyte solutions comprise a liquid electrolyte medium; a lithium-containing salt; 4-bromomethyl-1,3-dioxolan-2-one, and at least one electrochemical additive.

A nonaqueous electrolyte secondary battery according to one embodiment of the present disclosure comprises a positive electrode, a negative electrode and a nonaqueous electrolyte solution; the negative electrode comprises a negative electrode collector and a negative electrode active material layer that is provided on the negative electrode collector; the negative electrode active material layer contains, as negative electrode active materials, graphite particles A and graphite particles B; the graphite particles A have an internal void fraction of 5% or less; the graphite particles B have an internal void fraction of from 8% to 20%; if the negative electrode active material layer is halved in the thickness direction, a region on the half closer to the outer surface contains more graphite particles A than a region on the half closer to the negative electrode collector.

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte, wherein the negative electrode includes a negative electrode current collector and a negative electrode active material layer supported by the negative electrode current collector, when dividing the negative electrode active material layer into two layers of a first region and a second region having the same thickness, the second region is closer to the negative electrode current collector than the first region, the first region and the second region each contains graphite particles, a ratio P1/P2 of interparticle porosity P1 of the first region to interparticle porosity P2 of the second region is greater than 1, and the nonaqueous electrolyte includes at least one additive selected from the group consisting of a sulfite compound and a sulfate compound.

Disclosed is a secondary battery, comprising a positive electrode, a negative electrode, and an electrolyte, wherein the electrolyte comprises a lithium salt, an organic solvent, and an additive, wherein the additive comprises a fluorinated compound that accounts for 5-20% of the total mass of the electrolyte, and a polynitrile compound that accounts for 0.2-4% of the total mass of the electrolyte and a sulfate compound that accounts for 0.3-5% of the total mass of the electrolyte; and the negative electrode has a compacted density of not less than 1.55 g/cm3. When the secondary battery is used, the battery can still have both a high temperature characteristic and a low temperature charging ability under the conditions of a higher negative electrode density, thereby having market application prospects, and overcoming the problem of the performance of existing secondary batteries deteriorating when the compacted density of a negative electrode is improved.

Provided are an additive represented by Chemical Formula 1, an electrolyte for a lithium secondary battery including same, and a lithium secondary battery. The details of Chemical Formula 1 are as described in the specification.