Next-generation smart passive components for improved safety and performance in lithium-ion batteries

The separator and the current collectors (CCs) constitute two fundamental components of every lithium- ion battery (LIB). While not directly participating in the kinetics of the electrochemistry, these passive components are a principal determinant of the safety, performance, longevity, weight, and volume of a cell. Decreasing their weight or volume within the range where their functionalities are not negatively affected can improve a cell’s gravimetric or volumetric energy and power density. In this presentation, we describe a new approach to enhancing the safety and performance of LIBs of various sizes and chemistries that utilizes two next-generation smart passive components, namely, a metal–polymer composite CC (CCC) and a nanoporous ceramic separator (NPORE®). The CCC is fabricated by coating a 6- μm-thick polymer substrate with a thin (250 nm) layer of copper (Cu) metal on each side. High-density Cu elements (bridges) are also embedded within the substrate in this metallization process. The resulting material exhibits increased conductivity in both in-plane and out-of-plane directions. Functioning as a smart fuse, the CCC prevents additional inrush current from triggering a thermal runaway event that can potentially lead to a dangerous and inextinguishable fire in a cell when its internal temperature exceeds 250°C. Unsusceptible to melting and shrinking (even at very high temperatures), NPORE® is a proprietary, robust ceramic separator equipped with nanopores that further augments inherent cell safety. The combination of the CCC and NPORE® offers an innovative safety solution for LIBs of a wide range of chemistries and form factors.