Nippon Chemi-Con Corporation

Kazunori Takaki

Shuichi Ishimoto

Satoru Tsumeda

Kazuma Okura

Provided is a hybrid capacitor with an excellent long-term stability. A hybrid capacitor includes a positive electrodeincluding a positive-electrode active material layercontaining a carbon material employing a porous structure or a fibrous structure with an electric double layer capacity, and a negative electrodeincluding a negative-electrode active materialcontaining a material capable of adsorbing and releasing lithium ions. A lithium compound that traps protons is disposed between the positive-electrode active material layerand the negative-electrode active material layer. This hybrid capacitor further includes a separatordisposed between the positive-electrode active material layerand the negative-electrode active material layer, and the separator contains the lithium compound.

Hybrid capacitor and separator for hybrid capacitors

Provided is an electrochemical capacitor which has low DC internal resistance, and which minimizes increase in the DC internal resistance due to a high temperature experience. The electrochemical capacitor is provided with a positive electrode having a positive electrode active material layer containing activated carbon, a negative electrode having a negative electrode active material layer containing a spinel-type lithium titanate, and a separator holding a non-aqueous electrolytic solution containing a lithium salt between the positive electrode active material layer and the negative electrode active material layer, a 100% discharge capacity of lithium titanate being set to within a range of 2.2 to 7.0 times a 100% discharge capacity of activated carbon. During charging and discharging of the electrochemical capacitor, only the area near the surfaces of lithium titanate particles are utilized, lowering the DCIR and improving the stability of the DCIR.

Growing community of inventors

Tokyo, Japan

Kazunori Takaki