The challenges for further development of Li rechargeable batteries for electric vehicles are reviewed. Most important is safety, which requires development of a nonflammable electrolyte with either a larger window between its lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) or a constituent (or additive) that can develop rapidly a solid/ electrolyte-interface (SEI) layer to prevent plating of Li on a carbon anode during a fast charge of the battery. A high Li-ion conductivity (σ Li > 10 ―4 S/cm) in the electrolyte and across the electrode/ electrolyte interface is needed for a power battery. Important also is an increase in the density of the stored energy, which is the product of the voltage and capacity of reversible Li insertion/extraction into/from the electrodes. It will be difficult to design a better anode than carbon, but carbon requires formation of an SEI layer, which involves an irreversible capacity loss. The design of a cathode composed of environmentally benign, low-cost materials that has its electrochemical potential μ C well-matched to the HOMO of the electrolyte and allows access to two Li atoms per transition-metal cation would increase the energy density, but it is a daunting challenge. Two redox couples can be accessed where the cation redox couples are "pinned" at the top of the O 2p bands, but to take advantage of this possibility, it must be realized in a framework structure that can accept more than one Li atom per transition-metal cation. Moreover, such a situation represents an intrinsic voltage limit of the cathode, and matching this limit to the HOMO of the electrolyte requires the ability to tune the intrinsic voltage limit. Finally, the chemical compatibility in the battery must allow a long service life.

Challenges for Rechargeable Li Batteries

Electrolytes and interphases in Li-ion batteries and beyond.

Thermal runaway caused fire and explosion of lithium ion battery

A review on electrolyte additives for lithium-ion batteries

A review of conduction phenomena in Li-ion batteries

Additives-containing functional electrolytes for suppressing electrolyte decomposition in lithium-ion batteries

Disclosed is a lithium secondary battery which is excellent in battery characteristics such as long-term cycle characteristics, capacity and shelf life characteristics. Also disclosed is a nonaqueous electrolyte solution which can be used for such a lithium secondary battery. Specifically disclosed is a nonaqueous electrolyte solution for lithium secondary batteries obtained by dissolving an electrolyte salt in a nonaqueous solvent which is characterized by containing 0.01-10% by weight of a carboxylate compound represented by the general formula (I) below and 0.01-10% by weight or 0.01-10% by volume of a vinylene carbonate and/or 1,3-propane sultone. Also disclosed is a lithium secondary battery using such a nonaqueous electrolyte solution. (In the formula, R2 represents a hydrogen atom or COOR3 group, R1 and R3 respectively represent an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group or a phenyl group, and X represents an alkynylene group or an alkenylene group.)

Nonaqueous electrolyte solution and lithium secondary battery using same

Functional electrolytes: Novel type additives for cathode materials, providing high cycleability performance

A non-aqueous electrolyte comprising a non-aqueous solvent and a lithium salt dissolved therein, and a cyclic carbonate, linear carbonate, and vinylene carbonate having a chlorine content of 100 ppm or less, and a lithium secondary battery using the same

Non-aqueous electrolyte and lithium secondary battery using the same

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte which is excellent on battery characteristics such as electric capacity, cycle characteristics, and preservation characteristics and maintaining battery performance for a long period, and a lithium secondary battery using the nonaqueous electrolyte. SOLUTION: In the nonaqueous electrolyte wherein electrolytic salt is dissolved in a nonaqueous solvent, the nonaqueous electrolyte for a lithium secondary battery includes 0.1-10 wt.% ethylene carbonate derivative expressed by formula (I), and 0.01-10 wt.% pentafluorophenyloxy compound expressed by a triple-bond containing compound and/or formula (X), and the lithium secondary battery uses the nonaqueous electrolyte. Here, R 1 -R 3 in formula (I) independently show a hydrogen atom, a halogen atom, 2C-12C alkenyl group, 2C-12C alkynyl group, or 6C-18C aryl group, respectively, however, ethylene carbonate is excluded. R 15 in formula (X) shows 2-12C alkyl carbonyl group, 2C-12C alkoxy carbonyl group, 7C-18C aryloxy carbonyl group, or 1C-12C alkane sulfonyl group. However, at least one of hydrogen atoms held by R 15 may be replaced by a halogen atom or 6C-18C aryl group. COPYRIGHT: (C)2010,JPO&INPIT

Koji Abe

Papers

Additives-containing functional electrolytes for suppressing electrolyte decomposition in lithium-ion batteries

Nonaqueous electrolyte solution and lithium secondary battery using same

Functional electrolytes: Novel type additives for cathode materials, providing high cycleability performance

Non-aqueous electrolyte and lithium secondary battery using the same

Nonaqueous electrolyte and lithium secondary battery using the same