which can be realized by advancing battery materials and engineering the cell architectures. Particularly, automotive battery technology has been extensively evaluated and provides relatively stringent requirements on key performance indicators such as fast-charging capability and maximum energy density along with other critical factors (battery lifetime (>8 years), robustness to wide temperature, and safety), while non-EV batteries are flexible and tolerable in their design. [1] Putting differently, such practical standards guided for EV batteries assist battery scientists, at least in the academia, in aligning the ultimate goal and initiative for advanced battery developments, despite the recent application of new cell chemistry (typically known as post-lithium (Li) or beyond Li), [2] which have raised emerging challenges that require multiscale material-level understanding, design, and breakthroughs across the cell architecture. [3] Automotive battery technology has made great strides in terms of cost, process, and material perspective, yet advancing the batteries invariably starts with new battery chemistry and consequently new material chemistry in its major (e.g., cathode, anode, electrolyte, separator) and complementary cell components (e.g., current collector, binder, tap, packaging, etc.). Polymeric materials are indispensable to the design of batteries regardless of battery shape, size, chemistry, and manufacturing at the lab or industry scale as processable at every strategic point of battery production with multifunctionalities and cost-effectiveness. [4] From the conventional viewpoint, the role (or function) of polymeric materials has been confined to the structural support of composite electrodes and devices and the physical barrier between the cathode and anode for battery safety. Figure 1a shows the multiscale use of polymeric materials in a single cell and device. The polymeric binder serves as a chemical adhesive capable of maintaining the electrode integrity, ensuring electron/ion diffusion, and uniformly distributing the active material (Figure 1b). [5] A separator commonly fabricated from semicrystalline polyolefin (e.g., polyethylene (PE) and polypropylene (PP)), provides an ionic conduction path through a liquid electrolyte filling pores and electrically separates the two electrodes to prevent a battery short circuit, thereby directly related to safety (Figure 1c). [6] Additionally, a polymer has been used as a matrix for reducing the portion of flammable liquid solvent Riding on the rapid growth in electric vehicles and the stationary energy storage market, high-energy-density lithium-ion batteries and next-generation rechargeable batteries (i.e., advanced batteries) have been long-accepted as essential building blocks for future technology reaching the specific energy density of 400 Wh kg −1 at the cell-level. Such progress, mainly driven by the emerging electrode materials or electrolytes, necessitates the development of polymeric materials with advanced functionalities in the battery t...