Login / Signup

Quasi-Solid Sulfur Conversion for Energetic All-Solid-State Na-S Battery.

Hong ZhangMingli WangBin SongXiang-Long HuangWenli ZhangErhuan ZhangYingwen ChengKe Lu
Published in: Angewandte Chemie (International ed. in English) (2024)
The high theoretical energy density (1274 Wh kg -1 ) and high safety enable the all-solid-state Na-S batteries with great promise for stationary energy storage system. However, the uncontrollable solid-liquid-solid multiphase conversion and its associated sluggish polysulfides redox kinetics pose a great challenge in tunning the sulfur speciation pathway for practical Na-S electrochemistry. Herein, we propose a new design methodology for matrix featuring separated bi-catalytic sites that control the multi-step polysulfide transformation in tandem and direct quasi-solid reversible sulfur conversion during battery cycling. It is revealed that the N, P heteroatom hotspots are more favorable for catalyzing the long-chain polysulfides reduction, while PtNi nanocrystals manipulate the direct and full Na 2 S 4 to Na 2 S low-kinetic conversion during discharging. The electrodeposited Na 2 S on strongly coupled PtNi and N, P-codoped carbon host is extremely electroreactive and can be readily recovered back to S 8 without passivation of active species during battery recharging, which delivers a true tandem electrocatalytic quasi-solid sulfur conversion mechanism. Accordingly, stable cycling of the all-solid-state soft-package Na-S pouch cells with an attractive specific capacity of 876 mAh g S -1 and a high energy of 608 Wh kg cathode -1 (172 Wh kg -1 , based on the total mass of cathode and anode) at 60 °C are demonstrated.
Keyphrases