US Patent 8734983 Housing for electrochemical devices

An improved housing for a rolled-ribbon electrochemical device is provided. The housing comprises a fastener that aligns first and second cups during assembly and maintains electrode contact independent of external pressure on the housing eliminating the possibility of an open circuit state for a cell. In one alternative embodiment, the fastener comprises a stem that fits into a hollow tube and resists detachment from the tube. In another alternative embodiment, the fastener comprises a stem that fits into a grommet and resists detachment from the grommet. In yet another alternative embodiment, the fastener comprises a tube that fits into a grommet and resists detachment from the grommet.