Building K–C Anode with Ultrahigh Self‐Diffusion Coefficient for Solid State Potassium Metal Batteries Operating at −20 to 120 °C. Issue 16 (6th March 2023)

• Record Type: Journal Article
• Authors: Wu, Jian‐Fang; Zhou, Wang; Wang, Zixing; Wang, Wei‐Wei; Lan, Xuexia; Yan, Hanghang; Shi, Tuo; Hu, Renzong; Cui, Xiangyang; Xu, Chaohe; He, Xiangming; Mao, Bing‐Wei; Zhang, Tao; Liu, Jilei
• Is Part Of: Advanced materials. Volume 35:Issue 16(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-03-06
• Subjects: composite potassium anodes -- diffusion kinetics -- high‐temperature stability -- interfacial stability -- solid state potassium batteries; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202209833
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Solid state potassium (K) metal batteries are intriguing in grid‐scale energy storage, benefiting from the low cost, safety, and high energy density. However, their practical applications are impeded by poor K/solid electrolyte (SE) interfacial contact and limited capacity caused by the low K self‐diffusion coefficient, dendrite growth, and intrinsically low melting point/soft features of metallic K. Herein, a fused‐modeling strategy using potassiophilic carbon allotropes molted with K is demonstrated that can enhance the electrochemical performance/stability of the system via promoting K diffusion kinetics (2.37 × 10 −8 cm 2 s −1 ), creating a low interfacial resistance (≈1.3 Ω cm 2 ), suppressing dendrite growth, and maintaining mechanical/thermal stability at 200 °C. A homogeneous/stable K stripping/plating is consequently implemented with a high current density of 2.8 mA cm −2 (at 25 °C) and a record‐high areal capacity of 11.86 mAh cm −2 (at 0.2 mA cm −2 ). The enhanced K diffusion kinetics contribute to sustaining intimate interfacial contact, stabilizing the stripping/plating at high current densities. Full cells coupling ultrathin K–C composite anodes (≈50 µm) with Prussian blue cathodes and β/β″‐Al2 O3 SEs deliver a high energy density of 389 Wh kg −1 with a retention of 94.4% after 150 cycles and fantastic performances at −20 to 120 °C. Abstract : An ultrathin K–10% reduced graphene oxide anode is constructed, delivering promoted K diffusion kinetics and mechanical/thermal stability at 200 °C, which creates an interfacial resistance (≈1.3 Ω cm 2 ) with a current density of 2.8 mA cm −2 at 25 °C and an areal capacity of 11.86 mAh cm −2, enabling solid state potassium metal batteries operating at −20 to 120 °C.