Cryogenic energy storage enabled by dipole glass with unit-cell-level polar disorder

Cryogenic energy storage is crucial for the development of frontier nanoelectronics, including deep-space exploration (down to 90 K) and quantum computing (≤4 K). However, conventional electrochemical energy storage systems (such as secondary batteries and electrochemical capacitors) underperform at temperatures below ∼230 K due to restricted ion mobility. Although relaxor-based dielectric capacitors provide high energy efficiency (>80%) above ∼200 K, the intrinsic freezing/growth of polar nanodomains (that is, nanometric regions with local electric polarization) in the extended cryogenic regime (<120 K) limits their practical applications due to deteriorated polarization hysteresis losses. Here we overcome this detrimental effect by engineering a unit-cell disordered dipole-glass state near the antiferroelectric-paraelectric phase boundary. The antiferroelectric-derived dipole glass introduces enhanced unit-cell-level complexity in dipole interactions, thereby suppressing long-range ferroelectric order. This nanoengineering approach enables very low polarization hysteresis operation (with an efficiency >88%) down to 4 K, delivering an energy density of 211 J cm^-3 at 9 MV cm^-1, stability over 10⁸ charge/discharge cycles and microsecond-scale charge/discharge capability. This work introduces a dipole-glass paradigm that enables control of polar disorder at the unit-cell level, providing insights into the technology development of highly efficient energy storage systems with broad applications.