NOVELTY - The electrochemical cell comprises an electrode composed of a first electrode active material, a curable organic binder (49) and an electrical conduction unit operatively associated with the electrode active material. The electrode active material possesses a bimodal pore size distribution of which at least one size is mesoporous, and is converted from agglomerated nanoparticles, thermally.    USE - For electrochemical devices with innovative cell designs such as high power battery, solar cells and fast electrochromic devices.    ADVANTAGE - Charging and discharging capacity, cycle characteristics, reliability and safety of the electrochemical cell are excellent. Electrode formation process is simplified. Handling property of the solid microparticles are improved. A dense porous solid electrode that requires less inactive binder or electron conductive materials, is provided. Electrochemical devices are manufactured efficiently and economically.    DETAILED DESCRIPTION - The electrochemical cell comprises an electrode which is composed at least of a first electrode active material, a curable organic binder and an electrical conduction unit operatively associated with the electrode active material. The electrode active material possesses a bimodal pore size distribution of which at least one size is mesoporous, as measured by nitrogen porosimetry using the desorption isotherm. The bimodal mesoporous electrode active material is converted from agglomerated nanoparticles, thermally.    INDEPENDENT CLAIMS are also included for the following:    (1) A method of fabricating mesoporous sheet components for use as at least one of an anode, a cathode and a separator in an electrochemical cell. The method involves: (a) providing a first aqueous composition which comprises nanoparticles of a material selected from the anodic electrode active nanoparticles, cathodic electrode active nanoparticles and electrode inactive nanoparticles, (b) drying droplets of the aqueous composition to form discrete agglomerated microparticles (43,44), (c) covering agglomerated particles thermally to form discrete solid bimodal mesoporous microparticles with first average pore radius of 5 nm or less and a second average pore radius differing by at least about 5 nm, as measured by nitrogen porosimetry, (d) providing a second aqueous composition comprising the bimodal mesoporous microparticles and a curable binding material, (e) drying droplets of the second aqueous composition to form a free-flowing powder for discrete porous microparticles coated with a curable binding material, (f) depositing from a dispersed state a layer of the coated microparticles to a desired thickness and (g) bonding the microparticles by polymerizing, cross-linking, heat-setting or curing the binding material to form a mesoporous sheet component for an electrochemical cell with several passageways for an electrolyte; and    (2) A electrochemical device including an electrochemical cell selected from photoelectrochemical cell, electrochemichromic cell and electrochemical generator. The cell comprises at least an electrode active material, an electrical conduction unit operatively associated with electrode active material through a linking unit and an ionic conduction unit operatively associated with the electrode active material.    DESCRIPTION OF DRAWING(S) - The figure shows the perspective view of the selecting coating at the surface microparticle with a percolating network of binder and conductive particles.    Conductive particles (48)    Binder (49)    Microparticles (43, 44)