BINDER FOR LITHIUM CELL, COMPOSITION FOR PRODUCING ELECTRODE, AND ELECTRODE

摘要

It is an object of the present invention to provide an electrode capable of maintaining superior capacity retention without destruction of an electrode structure, even in the case of using an active material including silicon.;The present invention relates to “a binder for a lithium cell, the binder comprising polyacrylic acid cross-liked by a cross-linking agent selected from the compounds described in the general formulae [1] to [13] and the polymer described in the general formula [14] (provided that the one which includes a functional group-containing vinylidene fluoride-based polymer is excluded)”; a “composition for producing an electrode of a lithium cell, the composition comprising 1) an active material containing silicon, 2) a conductive assistant and 3) a cross-linked-type polyacrylic acid (provided that the one containing a functional group-containing vinylidene fluoride-based polymer is excluded)”; and an “electrode for a lithium cell, the electrode comprising 1) an active material containing silicon, 2) a conductive assistant, 3) a cross-linked-type polyacrylic acid, and 4) a current collector (provided that the one containing a functional group-containing vinylidene fluoride-based polymer is excluded)”.

主权项

1. A binder for a lithium cell comprising polyacrylic acid cross-liked by a cross-linking agent selected from the compounds described in the following general formulae [1] to [13] and the polymer described in the following general formula [14], provided that the one which includes a functional group-containing vinylidene fluoride-based polymer is excluded; wherein k represents an integer of 1 to 6,wherein R25 and R26 each independently represent a hydrogen atom or a methyl group, R20 represents an alkylene group having 1 to 20 carbon atoms, a group represented by the following general formula [2-1],
R17—Or  [2-1] wherein R17 represents an alkylene group having 1 to 6 carbon atoms, r represents an integer of 1 to 6, or the group represented by the following general formula [2-2]
R18—O—t—R19—  [2-2]wherein R18 and R19 each independently represent an alkylene group having 1 to 6 carbon atoms, t represents an integer of 1 to 12, wherein R1 to R6 and R61 each independently represent an alkylene group having 1 to 3 carbon atoms, wherein R7 to R10 each independently represent an alkylene group having 1 to 6 carbon atoms, 1 represents an integer of 1 to 6, m represents an integer of 0 to 6, v1 and v2 each independently represent an integer of 0 or 1, wherein R31 to R38 each independently represent a hydrogen atom, a vinyl group or a vinylketone group, and at least two or more groups thereof are a vinyl group or a vinylketone group, wherein R12 to R14 each independently represent an alkylene group having carbon 1 to 6 atoms, wherein Ar1 represents an aryl group having 6 to 10 carbon atoms, R15 represents an alkylene group having 1 to 6 carbon atoms, q represents an integer of 2 to 4, wherein Ar2 and Ar3 each independently represent an arylene group having 6 to 10 carbon atoms, R16 represents an alkylene group having 1 to 6 carbon atoms, wherein Ar4 represents an arylene group having 6 to 10 carbon atoms, wherein p represents an integer of 0 to 6, wherein, R11 represents an alkylene group having 1 to 6 carbon atoms, wherein R21 represents an alkylene group having 1 to 6 carbon atoms which has or does not have a substituent, an arylene group having 6 to 10 carbon atoms which has or does not have a substituent, or a group represented by the following general formula [12-A] wherein R35 represents an alkyl group having 1 to 6 carbon atoms, R36 represents an alkylene group having 1 to 6 carbon atoms, Ar5 represents an arylene group having 6 to 10 carbon atoms which may have b pieces of R35 as substituents, b represents an integer of 0 to 4, or the group represented by the following general formula [12-B] wherein R37 represents an alkylene group having 1 to 6 carbon atoms, R35, R36, Ar5 and b are the same as described above, wherein R22 each independently represents an alkyl group having 1 to 6 carbon atoms which has or does not have a substituent, an aryl group having 6 to 10 carbon atoms which has or does not have a substituent, or the group represented by the following general formula [13-A] wherein R40 represents an alkyl group having 1 to 6 carbon atoms, R41 represents an alkylene group having 1 to 6 carbon atoms, Ar6 represents an arylene group having 6 to 10 carbon atoms which have c pieces of R40 as substituents, c represents an integer of 0 to 5, wherein R23 represents an alkylene group having 1 to 6 carbon atoms which has or does not have a substituent, an arylene group having 6 to 10 carbon atoms which has or does not have a substituent, or a group represented by the following general formula [14-A] or [14-B] wherein R30 represents an alkyl group having 1 to 6 carbon atoms, R31 represents an alkylene group having 1 to 6 carbon atoms, Ar7 represents an arylene group having 6 to 10 carbon atoms which may have a pieces of R30 as substituents, a represents an integer of 0 to 4, or the group following general formula [14-C] wherein R32 represents an alkylene group having 1 to 6 carbon atoms, R30, R31, Ar7, and a are the same as described above, and s represents an integer of 10 to 10000.