Bridge the Gaps Between Lab‐Level Sodium‐Ion Coin Cells and Practical Pouch Cells

Sodium-ion batteries (SIBs) have garnered extensive interest in the academic and industrial sectors, primarily because of the abundance of sodium (Na) resources, manufacturing processes similar to those of lithium-ion batteries (LIBs), and high low-temperature resistance and rate capability. Recently, considerable efforts have been directed toward advancing the practical application of sodium-ion pouch cells; however, the transition from laboratory research to market implementation is hindered by an unclear understanding of the correlation between lab-level coin cells and practical pouch cells. Herein, the difference in energy density and cycle life between sodium-ion pouch cells and coin cells, and their numerous root causes are systematically analyzed and revealed. Then, the intrinsic defects in materials and interface instability issues associated with sodium-ion pouch cells are analyzed, and the research progress focusing on the cathode, anode, and electrolyte components is summarized. Finally, the standardization of assembly and testing to bridge the gap between the sodium-ion pouch cells and the coin cells is proposed for the SIB community. This review aims to provide valuable insights and support for promoting the development of SIBs from laboratory samples to industrial products.