Pre-lithiation carbon anodes mitigating potassium loss toward for high-performance potassium-ion energy storage devices

Abstract

Pre-potassiation technologies with the functions of providing additional potassium sources and/or mitigating potassium loss during cycling, make them capable of enhancing the energy density and cycling life of potassium-ion capacitors (PICs) and potassium-ion batteries (PIBs). However, many reported pre-potassiation strategies involve using high chemical reactivity potassium sources such as metallic potassium or K-containing additives, thereby increasing cost and risk in production. Herein, we propose a novel potassium-ion compensation strategy to fulfil the demand for high-performance potassium-ion full cells without using any high chemical reactivity potassium sources. This strategy is based on the foundation of that the pre-lithiation carbon anode with the preformed solid-electrolyte-interphase (SEI) layer can effectively mitigate potassium loss and not hinder the K+ diffusion from electrolyte to electrode during cell operation. PICs based on pre-lithiation carbon anodes including soft carbon, hard carbon, and graphite, show better capacitive performance than which based on pre-potassiation carbon counterparts. This versatile strategy is also applicable for high-performance PIBs. We believe that this design principle of implanting the mature pre-lithiation technologies into potassium-ion energy storage systems possesses far-reaching potential of resolving the scientific bottleneck of the immature pre-potassium technologies.