Homogeneous Metallic Deposition Regulated by Porous Framework and Selenization Interphase Toward Stable Sodium/Potassium Anodes

Abstract

Sodium (Na) metal has been considered as the most promising anode for achieving next‐generation battery system with high energy density and low cost. Nevertheless, the uncontrolled dendrites growth, infinite volume expansion and unstable solid/electrolyte interphase severely hinder the practical application of Na metal anode. Herein, a functional composite Na anode (Na2Se/Cu@Na) is achieved via infusing molten Na into the porous copper framework modified by cuprous selenide nanosheets. Combining experimental studies and theoretical calculations, the 3D framework and derivatives of Na2Se/Cu can synergistically buffer the volume expansion, redistribute Na+ flux, promote ions migration, and induce uniform Na+ deposition. Benefiting from these merits, the symmetrical cell of Na2Se/Cu@Na demonstrates a stable cycle lifespan over 500 h at 1 mA cm−2 in carbonate electrolyte. And the full battery paired with Na3V2(PO4)3 cathode delivers a stable capacity of 97 mAh g−1 after 800 cycles at 10 C. Furthermore, this structured framework can also be employed to construct composite potassium (K) anode and an outstanding cycle performance is achieved in the symmetrical cell (operating for 1000 h at 0.5 mA cm−2). This study paves a significant way of designing structured Na (K) metal anodes for synergistically improving the electrode stability.

Wide-temperature-range sodium-metal batteries: from fundamentals and obstacles to optimization

“…162,182 Besides, the direct contact of fresh Na metal/electrolyte causes unnecessary electrolyte consumption and a low Coulombic efficiency (CE) of SMBs. 183 As a result, the resistance at the interface increases substantially due to the continuous accumulation of the newly formed SEI on the Na metal. 155,183 Actually, the tension generated by Na + passing through the SEI can also lead to an unstable SEI (Fig.…”

“…183 As a result, the resistance at the interface increases substantially due to the continuous accumulation of the newly formed SEI on the Na metal. 155,183 Actually, the tension generated by Na + passing through the SEI can also lead to an unstable SEI (Fig. 5d).…”

Molecular Engineering on Solvation Structure of Carbonate Electrolyte toward Durable Sodium Metal Battery at −40 °C

“…It is probable that small proportion of ES is hard to form a dense SEI layer, S14, Supporting Information) is also lower than that of Na j j Na symmetrical cell due to the strong adsorption ability between Cu and Na. [18] To investigate the oxidative stability of the ES6-BLTE electrolyte, linear sweep voltammetry (LSV) was performed on Na j j aluminum (Al) cell (Figure S15, Supporting Information). Compared with the oxidation potential of the ether electrolyte (< 4 V), the BLTE and ES6-BLTE can remain stable to 4.2 and 4.5 V, respectively, which are related to the formation of the passivation layer on the surface of Al foil in carbonate electrolyte, facilitating the utilization of high-voltage cathodes.…”

Ion-Exchange Route Induced Heterostructured CoS2/FeS Nanoparticles Confined in Hollow N-Doped Carbon Frameworks for Enhanced Sodium Storage Performance

“…In the past decade, rechargeable sodium-ion batteries (SIBs) have become more competitive and attracted extensive research attention because of their great advantages including low cost, natural abundant resources, environmental safety, and suitable redox potential (−2.71 eV vs SHE) of Na + /Na, which is thereby recognized as one of the most promising candidates to supplement or even replace the mainstream lithium-ion batteries (LIBs). − Owing to the much larger ionic size of Na + in comparison with that of Li + , the commercialized anode of graphite for LIBs exhibits a significantly low capacity of sodium storage (35 mAh g –1 ) as expected . Hence, it is fundamentally important to explore alternative anode materials for SIBs with efficient accommodation of Na + .…”