Design Principles of Sodium/Potassium Protection Layer for High‐Power High‐Energy Sodium/Potassium‐Metal Batteries in Carbonate Electrolytes: a Case Study of Na2Te/K2Te. Issue 48 (27th September 2021)

• Record Type: Journal Article
• Authors: Yang, Hai; He, Fuxiang; Li, Menghao; Huang, Fanyang; Chen, Zhihao; Shi, Pengcheng; Liu, Fanfan; Jiang, Yu; He, Lixin; Gu, Meng; Yu, Yan
• Is Part Of: Advanced materials. Volume 33:Issue 48(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-09-27
• Subjects: artificial protection layer in electrolytes -- high energy density -- potassium‐metal batteries -- sodium‐metal batteries -- theoretical simulations; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202106353
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: The sodium (potassium)‐metal anodes combine low‐cost, high theoretical capacity, and high energy density, demonstrating promising application in sodium (potassium)‐metal batteries. However, the dendrites' growth on the surface of Na (K) has impeded their practical application. Herein, density functional theory (DFT) results predict Na2 Te/K2 Te is beneficial for Na + /K + transport and can effectively suppress the formation of the dendrites because of low Na + /K + migration energy barrier and ultrahigh Na + /K + diffusion coefficient of 3.7 × 10 −10 cm 2 s −1 /1.6 × 10 −10 cm 2 s −1 (300 K), respectively. Then a Na2 Te protection layer is prepared by directly painting the nanosized Te powder onto the sodium‐metal surface. The Na@Na2 Te anode can last for 700 h in low‐cost carbonate electrolytes (1 mA cm −2, 1 mAh cm −2 ), and the corresponding Na3 V2 (PO4 )3 //Na@Na2 Te full cell exhibits high energy density of 223 Wh kg −1 at an unprecedented power density of 29687 W kg −1 as well as an ultrahigh capacity retention of 93% after 3000 cycles at 20 C. Besides, the K@K2 Te‐based potassium‐metal full battery also demonstrates high power density of 20 577 W kg −1 with energy density of 154 Wh kg −1 . This work opens up a new and promising avenue to stabilize sodium (potassium)‐metal anodes with simple and low‐cost interfacial layers. Abstract : A Na2 Te (K2 Te) protection layer with high ionic conductivity, low electronic conductivity, and high mechanical stability on a Na (K) metal anode is designed and prepared. The Na@Na2 Te (K@K2 Te) realizes excellent electrochemi cal performance for sodium‐metal (potassiummetal) batteries of both symmetrical cells and full batteries in widely used carbonate electrolytes.