The present invention provides a binder for a secondary battery that can reduce the initial resistance value of the secondary battery. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains repeating units represented by formulae (1), (2), and (3):

##STR00001## in formula (1), R.sup.1 is a hydrogen atom or a methyl group, and M is a hydrogen atom or an alkali metal atom; and in formula (3), R.sup.2 is a hydrogen atom or a methyl group; and when a total ratio of repeating units constituting the polymer compound is taken as 100 mol %, a total ratio of the repeating unit represented by formula (3) is less than 2 mol %.

The present invention provides a binder for a secondary battery that can reduce the initial resistance value of the secondary battery. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains repeating units represented by formulae (1), (2), and (3):

##STR00001## in formula (1), R.sup.1 is a hydrogen atom or a methyl group, and M is a hydrogen atom or an alkali metal atom; and in formula (3), R.sup.2 is a hydrogen atom or a methyl group; and when a total ratio of repeating units constituting the polymer compound is taken as 100 mol %, a total ratio of the repeating unit represented by formula (3) is less than 2 mol %.

According to the present disclosure, it is possible to inhibit the electrically conductive foreign substance from falling off and being peeled off from the electrode plate that has been already manufactured, so as to contribute in improving the safety property of the secondary battery. The manufacturing method of the electrode plate herein disclosed includes a precursor preparing step for preparing an electrode precursor 20A including an active material provided area A1 in which an electrode active material layer 24 is provided on a surface of the electrode core 22 and including a core exposed area A2 in which the electrode active material layer 24 is not provided and the electrode core 22 is exposed, and an active material provided area cutting step for cutting the active material provided area A1 by a pulse laser, and a core exposed area cutting step for cutting the core exposed area A2 by the pulse laser. Then, in the case where the pulse width (ns) of the pulse laser is represented by X and the lap rate (%) is represented by Y for the core exposed area cutting step, a condition represented by Y≥−3log X+106 is satisfied. According to the manufacturing method of the electrode plate as described above, it is possible to inhibit the electrically conductive foreign substance from falling off and being peeled off from the electrode plate that has been already manufactured, and thus it is possible to contribute in improving the safety property of the secondary battery.

According to the present disclosure, it is possible to inhibit the electrically conductive foreign substance from falling off and being peeled off from the electrode plate that has been already manufactured, so as to contribute in improving the safety property of the secondary battery. The manufacturing method of the electrode plate herein disclosed includes a precursor preparing step for preparing an electrode precursor 20A including an active material provided area A1 in which an electrode active material layer 24 is provided on a surface of the electrode core 22 and including a core exposed area A2 in which the electrode active material layer 24 is not provided and the electrode core 22 is exposed, and an active material provided area cutting step for cutting the active material provided area A1 by a pulse laser, and a core exposed area cutting step for cutting the core exposed area A2 by the pulse laser. Then, in the case where the pulse width (ns) of the pulse laser is represented by X and the lap rate (%) is represented by Y for the core exposed area cutting step, a condition represented by Y≥−3log X+106 is satisfied. According to the manufacturing method of the electrode plate as described above, it is possible to inhibit the electrically conductive foreign substance from falling off and being peeled off from the electrode plate that has been already manufactured, and thus it is possible to contribute in improving the safety property of the secondary battery.

A battery module including: a battery stack of battery cells having opposite ends to which a plurality of electrode tabs are connected; end-side bus bar assemblies formed at opposite ends of the battery stack, respectively, and electrically connecting the electrode tabs of the battery cells; and a case accommodating the battery stack and the end-side bus bar assemblies.

An all-solid secondary battery includes: a cathode layer; an anode layer; and a solid electrolyte between the cathode layer and the anode layer, wherein the anode layer includes an anode current collector and a first anode active material layer on the anode current collector, the first anode active material layer includes a modified ordered mesoporous carbon, and an oxygen content of a surface of the modified ordered mesoporous carbon is about 3 atomic percent to about 10 atomic percent, based on a total content of the surface, when determined by an X-ray photoelectron spectroscopy spectrum of the surface of the modified ordered mesoporous carbon.

An anode for a secondary battery including an anode active material and a secondary battery including the anode and having improved stability and reduced resistance are disclosed. In an aspect, the anode active material includes a silicon-based active material having a specific surface area (BET) in a range from 0.5 m.sup.2/g to 5 m.sup.2/g, a first carbon-based active material having an average particle diameter (D50) in a range from 1 μm to 4 μm, and a second carbon-based active material having an average particle diameter greater than that of the first carbon-based active material.

An anode for a secondary battery including an anode active material and a secondary battery including the anode and having improved stability and reduced resistance are disclosed. In an aspect, the anode active material includes a silicon-based active material having a specific surface area (BET) in a range from 0.5 m.sup.2/g to 5 m.sup.2/g, a first carbon-based active material having an average particle diameter (D50) in a range from 1 μm to 4 μm, and a second carbon-based active material having an average particle diameter greater than that of the first carbon-based active material.

Composites comprising an exfoliated graphite support material having a degree of graphitization g in an range of 50 to 93%, obtained by XRD Rietveld analysis, which is coated with ZnO nanoparticles. These composites are produced by three different methods: A) (syn) the method comprises the following consecutive steps: i) a Zn(II)salt is dissolved in a solvent ii) graphite and a base are added simultaneously iii) the mixture is stirred under impact of ultrasound iv) the solvent is removed from the suspension or B) (pre) the method comprises the following consecutive steps: i) graphite is suspended in a solvent and exfoliated via impact of ultrasound ii) a Zn(II)salt and a base are added simultaneously forming nano-ZnO particles iii) the mixture is stirred iv) the solvent is removed from the suspension or C) (post) the method comprises the following steps: i) a Zn(II)salt and a base are mixed in a solvent in a first reactor forming nano-ZnO particles ii) graphite is exfoliated via impact of ultrasound in a second reactor iii) both suspensions of i) and ii) are mixed together iv) after step iii) the solvent is removed from the suspension. These coated composites may be tempered in a further step and again coated and again tempered.

A negative electrode active material containing a negative electrode active material particle which includes a silicon compound particle containing a silicon compound (SiO.sub.x: 0.5≤x≤1.6). The silicon compound particle has three or more peaks in a chemical shift value ranging from −40 ppm to −120 ppm but has no peak in a chemical shift value within a range of −65±3 ppm in a spectrum obtained from .sup.29Si-MAS-NMR of the silicon compound particle. This provides a negative electrode active material capable of improving cycle characteristics when it is used as a negative electrode active material for a secondary battery.