Pressure-free solid batteries achieve liquid-like conductivity

Chinese researchers have developed a flexible composite solid electrolyte for all-solid-state lithium batteries that achieves ionic conductivity comparable to liquid electrolytes while operating without external pressure. This innovation addresses a key challenge in solid-state batteries, which traditionally face a trade-off between fast ion transport and mechanical stability. The new electrolyte features a layered composite structure with alternating sheets of perpendicularly aligned inorganic nanosheets (LixMyPS3, where M is Cd or Mn) and polyethylene oxide polymer layers. The inorganic layers provide continuous superionic pathways for ion conduction, while the polymer layers offer mechanical flexibility and maintain close electrode contact, enabling liquid-like ionic conductivity (up to 10.2 mS cm⁻¹ at 25°C) without the need for heavy stack pressure. The pressure-free operation simplifies battery design by eliminating the need for complex clamping systems, potentially reducing manufacturing complexity and cost. The researchers demonstrated the electrolyte's performance in working battery cells, including Li||LiNi0.8Co0.1Mn0