While batteries excel in storage capacity, they fall short in speed, unable to charge or discharge rapidly. Capacitors fill this gap, delivering the quick energy bursts that power-intensive devices demand. Some smartphones, for example, contain up to 500 capacitors, and laptops around 800. Just don't ask the capacitor to store its energy too long. Within capacitors, ferroelectric materials offer high maximum polarization. That's useful for ultra-fast charging and discharging, but it can limit the effectiveness of energy storage or the "relaxation time" of a conductor. "This precise control over relaxation time holds promise for a wide array of applications and has the potential to accelerate the development of highly efficient energy storage systems," the study authors write.