Stable Solid Electrolyte Interphase for Long-Life Potassium Metal Batteries

• Potassium (K) is considered to be the most suitable anode material for rechargeable K batteries because of its high theoretical capacity (686 mAh g(-1)) and low redox potential (-2.93 V vs SHE). However, uneven electrodeposition of K during cycling usually leads to the growth of dendrites, resulting in low Coulombic efficiency and compromising battery safety. Herein, we develop a strategy for stabilizing K metal through simple interface control. The conductive passivation layer can be controllably designed by a spontaneous chemical reaction when a K metal foil is kept in contact with a liquid-phase potassium-polysulfide (PPS); this guides the formation of an electronically and ionically conductive solid electrolyte interphase layer including K2S compound, enabling dense K plating with a dendrite-free morphology. Compared to the bare K metal anode, the PPS-treated K metal anode demonstrates superior cycling stability in symmetric half cells and full cells using a TiS2 cathode under practical constraints.

Subject headings

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik -- Annan kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering -- Other Chemical Engineering (hsv//eng)

Publication and Content Type

art (subject category)

ref (subject category)