Surface‐Confined Disordered Hydrogen Bonds Enable Efficient Lithium Transport in All‐Solid‐State PEO‐Based Lithium Battery

Polyethylene oxide (PEO)‐based electrolytes are essential to advance all‐solid‐state lithium batteries (ASSLBs) with high safety/energy density due to their inherent flexibility and scalability. However, the inefficient Li+ transport in PEO often leads to poor rate performance and diminished stability of the ASSLBs. The regulation of intermolecular H‐bonds is regarded as one of the most effective approaches to enable efficient Li+ transport, while the practical performances are hindered by the electrochemical instability of free H‐bond donors and the constrained mobility of highly ordered H‐bonding structures. To overcome these challenges, we develop a surface‐confined disordered H‐bond system with stable donor‐acceptor interactions to construct a loosened chain segments/ions arrangement in the bulk phase of PEO‐based electrolytes, realizing the crystallization inhibition of PEO, weak coordination of Li+ and entrapment of anions, which are conducive to efficient Li+ transport and stable Li+ deposition. The rationally designed LiFePO4‐based ASSLB demonstrates a long cycle‐life of over 400 cycles at 1.0 C and 65 °C with a capacity retention rate of 87.5%, surpassing most of the currently reported polymer‐based ASSLBs. This work highlights the importance of confined disordered H‐bonds on Li+ transport in an all‐solid‐state battery system, paving the way for the future design of polymer‐based ASSLBs.