Uniform P2-K_0.6CoO₂ Microcubes as a High-Energy Cathode Material for Potassium-Ion Batteries

Abstract

Layered transition-metal (TM) oxides have drawn ever-growing interest as positive electrode materials in potassium-ion batteries (PIBs). Nevertheless, the practical implementation of these positive electrode materials is seriously hampered by their inferior cyclic property and rate performance. Reported here is a self-templating strategy to prepare homogeneous P2-K0.6CoO2 (KCO) microcubes. Benefiting from the unusual microcube architecture, the interface between the electrolyte and the active material is considerably diminished. As a result, the KCO microcubes manifest boosted electrochemical properties for potassium storage including large reversible capacity (87.2 mAh g–1 under 20 mA g–1), superior rate performance, and ultralong cyclic steady (an improved capacity retention of 86.9% under 40 mA g–1 after 1000 cycles). More importantly, the fabrication approach can be effectively extended to prepare other layered TM oxide (P3-K0.5MnO2, P3-K0.5Mn0.8Fe0.2O2, P2-K0.6Co0.67Mn0.33O2, and P2-K0.6Co0.66Mn0.17Ni0.17O2) microcubes and nonlayered TM oxide (KFeO2) microcubes.

Zinc‐Doping Strategy on P2‐Type Mn‐Based Layered Oxide Cathode for High‐Performance Potassium‐ion Batteries

“…[ 4,5 ] Compared with LIBs, sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs) become two promising alternatives because of their more abundant resources and the same intercalation chemistry as LIBs. [ 6–8 ] In particular, the lower standard redox potential of K/K + (−2.936 V vs SHE) makes PIBs a superior alternative to SIBs by converting to a higher operating voltage and energy density. [ 9 ]…”

Free-Standing Carbon Nanofiber Composite Networks Derived from Bacterial Cellulose and Polypyrrole for Ultrastable Potassium-Ion Batteries

“…With the emergence of energy crisis, secondary batteries have attracted the extensive attention of many researchers. As the most important battery system at present, lithium-ion batteries (LIBs) have the advantages of a high capacity, a long cycle life, and a wide application range, but the low reserves and high price limit their continuous application. − With the development of a new energy system, the research on sodium-ion batteries (NIBs) and potassium-ion batteries (KIBs) has become more and more important due to more abundance in the Earth’s crust. − KIBs have a higher reaction voltage than NIBs, improving their energy density. Meanwhile, the suitability of KIBs with graphite can also greatly improve their application potential.…”

Single-Shell Multiple-Core MnO@C Hollow Carbon Nanospheres for Low-Temperature Lithium Storage

“…Numerous portable electronic devices and electric vehicles now primarily run on lithium-ion batteries (LIBs). − The usage of innovative electrode materials has received considerable attention since they have a significant impact on the properties of LIBs. The application of LIBs at low temperatures is of great interest as electric vehicles and/or other electronic devices can inevitably be used at subzero temperatures.…”