Abstract: The present invention discloses a cathode material for lithium ion secondary battery. The cathode material is in the form of powder particles. The powder particle includes a bulk portion and a coating portion coated on the outer surface of the bulk portion. The bulk portion is formed of at least one first cathode material which is a lithium-nickel based composite oxide. The first cathode material has electrochemical activity and has high charging-discharging specific capacity at a charged voltage of 4.2V versus Li/Li+. The coating portion is formed of at least one second cathode material. The second cathode material has no electrochemical activity or has low charging-discharging specific capacity at a charged voltage of 4.2V versus Li/Li+. Lithium ion secondary battery using the cathode material has high energy density, cycling stability, security, and output power.

Abstract: The present invention relates to a preparation method of ionic liquids, particularly to a one-step reaction method used for synthesizing quaternary ammonium compounds or quaternary phosphonium compounds. In the method, a nitrogenous or phosphorous compound, a proton compound, and a carbonate ester are added into a reactor simultaneously to synthesize corresponding the quaternary ammonium ionic liquid or the quaternary phosphonium ionic liquid through said one-step reaction, i.e., ‘one-pot method’ reaction, during which three reactants are involved. The present invention also provides a lithium ion secondary battery comprising the ionic liquid prepared by above-mentioned preparation method. The ionic liquid preparation method of the present invention can widen the choice range of raw materials needed when preparing ionic liquids, and further widen the synthesized ionic liquid species.

Abstract: The present invention relates to a preparation method of ionic liquids, particularly to a one-step reaction method used for synthesizing quaternary ammonium compounds or quaternary phosphonium compounds. In the method, a nitrogenous or phosphorous compound, a proton compound, and a carbonate ester are added into a reactor simultaneously to synthesize corresponding the quaternary ammonium ionic liquid or the quaternary phosphonium ionic liquid through said one-step reaction, i.e., ‘one-pot method’ reaction, during which three reactants are involved. The present invention also provides a lithium ion secondary battery comprising the ionic liquid prepared by above-mentioned preparation method. The ionic liquid preparation method of the present invention can widen the choice range of raw materials needed when preparing ionic liquids, and further widen the synthesized ionic liquid species.

Abstract: A two-step pathway for preparing high pure quaternary phosphonium salts is disclosed. In the first step, hydrogen phosphide (PH3) or a higher phosphine reacts with a protonic compound to produce a phosphonium salt, which then reacts with a carbonic acid diester to produce a quaternary phosphonium salt in the second step. On one hand, hydrogen phosphide (PH3) and higher phosphines, including primary phosphines, secondary phosphines, and tertiary phosphines, after neutralization with protonic compound, become sufficiently reactive and can be alkylated by carbonic acid diester to form quaternary phosphonium cations. On the other hand, as an anion-exchange procedure is completely avoided, the process not only gives quaternary phosphonium salts of high purity, but also gives people freedom to design the cation and the anion of a quaternary phosphonium salt synchronously by choosing a preferred phosphine and a protonic compound that can supply a desired anion.

Abstract: A graphite negative material for a lithium-ion battery includes a number of graphite layers parallel to each other. A number of channels are through the graphite layers. And the channels are capable of allowing lithium ions to pass therethrough freely. A method for preparing the graphite negative material and a lithium-ion battery including the graphite negative material are also provided.

Abstract: The present invention discloses a cathode material for lithium ion secondary battery. The cathode material is in the form of powder particles. The powder particle includes a bulk portion and a coating portion coated on the outer surface of the bulk portion. The bulk portion is formed of at least one first cathode material which is a lithium-nickel based composite oxide. The first cathode material has electrochemical activity and has high charging-discharging specific capacity at a charged voltage of 4.2V versus Li/Li+. The coating portion is formed of at least one second cathode material. The second cathode material has no electrochemical activity or has low charging-discharging specific capacity at a charged voltage of 4.2V versus Li/Li+. Lithium ion secondary battery using the cathode material has high energy density, cycling stability, security, and output power.

Abstract: A graphite negative material for a lithium-ion battery includes a number of graphite layers parallel to each other. A number of channels are through the graphite layers. And the channels are capable of allowing lithium ions to pass therethrough freely. A method for preparing the graphite negative material and a lithium-ion battery including the graphite negative material are also provided.

Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, a separator and an ionic liquid electrolyte. The separator is a polar porous membrane. The ionic liquid electrolyte and the separator made of the polar porous are used in the lithium ion secondary batteries, which can improve the electrochemical performance of the lithium ion secondary batteries.