According to a first embodiment, there is provided a positive electrode including a positive electrode active material-containing layer containing a first active material having a spinel type crystal structure. The positive electrode satisfies the formulas (1) to (3) when combined with a negative electrode including a negative electrode active material-containing layer containing a first active material having a spinel type crystal structure: 0.5≤a1/b1≤1.5 (1); 0.4≤a2/b2≤1.4 (2); and 0.5≤a3/b3≤2.3 (3), where a1 and b1 are a pore volume per 1 g weight, a2 and b2 are a pore specific surface area, and a3 and b3 are a median diameter in pore distribution, for the positive and negative electrode active material-containing layers, respectively.

Provided is an alkaline secondary battery including: a stacked-cell battery in which multiple single cell elements having a configuration of an alkaline secondary battery are stacked; and a box-shaped case made of resin in which the stacked-cell battery is housed vertically. The box-shaped case has a bottom, a pair of long-side walls parallel to the stacked-cell battery, a pair of short-side walls perpendicular to the stacked-cell battery, and a lid part. The lid part has a vulnerable portion having a smaller thickness than other portions of the lid part, the thickness of the vulnerable portion is 0.1 to 1.0 mm, and a proportion of an area of the vulnerable portion with respect to a total area of the lid part in a plan view is 10 to 40%.

Ionomer membranes for fuel cells and related devices are described. An ionomer membrane may be configured with a plurality of anode-side protrusions and/or a plurality of cathode-side protrusions. A filler material(s) may be deposited into voids of an ionomer membrane. Example filler materials include, but are not limited to, platinum (Pt), palladium (Pd), cobalt (Co), nickel (Ni), gold (Au), silver (Ag), iridium (Ir), etc., and their alloys on carbon supports.

According to a first embodiment, there is provided a positive electrode including a positive electrode active material-containing layer containing a first active material having a spinel type crystal structure. The positive electrode satisfies the formulas (1) to (3) when combined with a negative electrode including a negative electrode active material-containing layer containing a first active material having a spinel type crystal structure: 0.5a1/b11.5 (1); 0.4a2/b21.4 (2); and 0.5a3/b32.3 (3), where a1 and b1 are a pore volume per 1 g weight, a2 and b2 are a pore specific surface area, and a3 and b3 are a median diameter in pore distribution, for the positive and negative electrode active material-containing layers, respectively.

Provided is an alkaline secondary battery including: a stacked-cell battery in which multiple single cell elements having a configuration of an alkaline secondary battery are stacked; and a box-shaped case made of resin in which the stacked-cell battery is housed vertically. The box-shaped case has a bottom, a pair of long-side walls parallel to the stacked-cell battery, a pair of short-side walls perpendicular to the stacked-cell battery, and a lid part. The lid part has a vulnerable portion having a smaller thickness than other portions of the lid part, the thickness of the vulnerable portion is 0.1 to 1.0 mm, and a proportion of an area of the vulnerable portion with respect to a total area of the lid part in a plan view is 10 to 40%.

The present invention provides solid-state primary and secondary electrochemical cells, cathode slurries in an electrochemical cell, and electrode materials, and the corresponding methods of making and using the same.