A lithium secondary battery includes: a positive electrode that includes a positive electrode active material including a compound represented by the following Formula (X) and a binder including a polyvinylidene fluoride having a weight average molecular weight of from 300,000 to 950,000; a negative electrode; and a non-aqueous electrolytic solution that includes at least one of lithium difluorophosphate or lithium monofluorophosphate. In Formula (X), each of a, b, and c is independently more than 0 but less than 1.00, and the sum of a, b, and c is from 0.99 to 1.00.

LiNi.sub.aMn.sub.bCo.sub.cO.sub.2  (X)

An electrolyte is provided. The electrolyte includes a solvent containing propylene carbonate (PC); a lithium salt dissolved in the solvent; a first additive dissolved in the solvent, the first additive being configured to stabilize an anode solid electrolyte interphase; a second additive dissolved in the solvent, the second additive being configured to stabilize at least one of an anode, a cathode, or the lithium salt; and a third additive dissolved in the solvent, the third additive being configured to stabilize at least one of an anode, a cathode, or the lithium salt. The first, second, and third additives are chemically distinct. Electrochemical cells including the electrolyte are also provided.

The electrolyte for a lithium secondary battery includes: a lithium salt; a solvent; and a functional additive, wherein the functional additive includes 1,2-bis(maleimido)ethane, represented by the following formula 1: ##STR00001##

An electrochemical apparatus, including an electrolyte and a positive electrode, where the electrolyte includes ethylene carbonate and propylene carbonate, the positive electrode includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, and the positive electrode active material layer includes a positive electrode active material, where percentages of ethylene carbonate and propylene carbonate satisfy a specific relationship, and under an X-ray diffraction (XRD) test, a peak intensity I.sub.003 of plane 003 of the positive electrode active material layer and a peak intensity I.sub.104 of plane 104 of the positive electrode active material layer satisfy a specific relationship. With the above configuration, the electrochemical apparatus of this application shows excellent performances, especially the high-temperature floating charge performance.

A reforming element for a molten carbonate fuel cell stack and corresponding methods are provided that can reduce or minimize temperature differences within the fuel cell stack when operating the fuel cell stack with enhanced CO.sub.2 utilization. The reforming element can include at least one surface with a reforming catalyst deposited on the surface. A difference between the minimum and maximum reforming catalyst density and/or activity on a first portion of the at least one surface can be 20% to 75%, with the highest catalyst densities and/or activities being in proximity to the side of the fuel cell stack corresponding to at least one of the anode inlet and the cathode inlet.

The present disclosure relates to a lithium secondary battery including: a non-aqueous electrolyte including a lithium salt, an organic solvent, a first additive represented by Chemical Formula 1 and a second additive represented by Chemical Formula 2; a positive electrode including a positive electrode active material including a lithium iron phosphate-based composite oxide; a negative electrode including an negative electrode active material; and a separator interposed between the positive electrode and the negative electrode.

An electrolyte including a compound

##STR00001##

R.sub.11 is a covalent bond, a substituted or unsubstituted C.sub.1-C.sub.20 alkylidene group, a substituted or unsubstituted C.sub.2-C.sub.20 alkenylene group, a substituted or unsubstituted C.sub.2-C.sub.20 alkynylene group, a substituted or unsubstituted C.sub.6-C.sub.20 arylene group, a substituted or unsubstituted C.sub.3-C.sub.20 heteroarylene group, a substituted or unsubstituted C.sub.3-C.sub.20 cycloalkylene group,

##STR00002##

or a combination thereof. R.sub.12, R.sub.13, and R.sub.14 are a substituted or unsubstituted C.sub.1-C.sub.20 alkylidene group, C.sub.2-C.sub.20 alkenylene group, C.sub.2-C.sub.20 alkynylene group, C.sub.6-C.sub.20 arylene group, C.sub.3-C.sub.20 heteroarylene group, or C.sub.3-C.sub.20 cycloalkylene group;

##STR00003##

or a combination thereof. R.sub.15 and R.sub.16 are a C.sub.1-C.sub.20 alkylidene group, a substituted or unsubstituted C.sub.2-C.sub.20 alkenylene group, a substituted or unsubstituted C.sub.2-C.sub.20 alkynylene group, a substituted or unsubstituted C.sub.6-C.sub.20 arylene group, a substituted or unsubstituted C.sub.3-C.sub.20 heteroarylene group, or a substituted or unsubstituted C.sub.3-C.sub.20 cycloalkylene group.

Provided are an electrolyte for a manganese ion battery and a manganese ion battery using the same. In the electrolyte for a manganese ion battery, manganese salt is dissolved in an organic solvent and dissociated into manganese ions and anions, and manganese ions are used as a charge transfer material in the electrolyte to enable charging and discharging of the manganese ion battery. The electrolyte for a manganese ion battery uses manganese ions as a charge transport material and thus has good compatibility with manganese metal used as a negative electrode. In addition, the manganese ion battery to which the electrolyte is applied can use manganese metal, which is significantly cheaper than lithium metal and has a lower reactivity than lithium metal, as a negative electrode, so there are fewer side reactions during battery operation.

A rechargeable lithium battery includes a positive electrode including a positive electrode active material including a secondary particle in which a plurality of primary particles are aggregated, the secondary particle having at least a portion of the primary particles radially arranged and comprising a lithium nickel-based composite oxide, and a boron coating layer on the surface of the secondary particle and including lithium borate; a negative electrode; a separator between the positive electrode and the negative electrode; an electrolyte including vinylene carbonate; and a case containing the positive electrode, the negative electrode, the separator, and the electrolyte.

A lithium secondary battery includes a cathode including a cathode active material that includes lithium metal oxide particles, an anode facing the cathode and including an anode active material, and an electrolyte solution including a lithium salt and an organic solvent. The lithium metal oxide particles contain at least 80 mol % of nickel and less than 10 mol % of manganese among all elements excluding lithium and oxygen. The organic solvent includes an acetate-based compound in an amount from 1 vol % to 10 vol % based on a total volume of the organic solvent.