Abstract: Methods of making a battery component are provided. The method comprises gas phase depositing a composition onto an electrode, the composition comprising a first component and a second component, and removing at least a portion of the second component to form a separator comprising a porous polymer film on the electrode. The first component is selected from the group consisting of polymers, dimers and monomers. In some embodiments, the second component is selected from the group consisting of polymers, dimers and monomers and is different from the first component. The first component and the second component each form separate polymer phases and together form a layer. In some embodiments, the second component is selected from the group consisting of by-products and remaining portions of the first component from the forming the first polymer.

Abstract: A battery pack is described. The battery pack includes a plurality of electrochemical cells, wherein the electrochemical cells are isolated from each other by a concrete. The concrete includes a composite cement having from about 20 percent to about 80 percent aggregate of high packing density, by weight of the composite cement. Methods for providing electrical isolation between individual electrochemical cells are also described.

Abstract: In certain embodiments, a battery component comprises an electrode and a separator deposited on a surface of the electrode is provided. The separator comprises a porous poly(para-xylylene) film. In some embodiments, the electrode can include at least one cavity or protrusion, and the separator layer can be gas phase deposited directly on the electrode. In certain embodiments, methods of making a battery component are also provided.