Kinetic control of cathode-to-anode switching in a niobium-modified sodium vanadate-borate glass-ceramic for sodium-ion batteries
Year: 2026
Type: article
Abstract: Sodium-ion batteries require electrodes that combine structural stability with electrochemical tunability; a combination glass-ceramics are uniquely positioned to deliver through controlled crystallization. We demonstrate that calcination time alone controls the operating potential of a niobium-modified sodium vanadate-borate glass-ceramic: 5 h at 400°C produces stable cathode operation (110 mAhg⁻¹, 78% retention over 400 cycles), while 10 h treatment shifts activity to a lower operating potential suited to anode function, delivering high initial capacity (1382 mAh g⁻¹ at 0.1 C-rate) that fades substantially, retaining 194 mAh g⁻¹ (20% of post-formation capacity) after 300 cycles. This transition is accompanied by structural evolution of the glass-ceramic matrix, including crystallization of the vanadate-borate network and development of niobium-containing domains. The anode's capacity fade is consistent with SEI growth and progressive loss of electrochemically active material. Despite this fade, a proof-of-concept full cell operates for 100 cycles with 85% Coulombic efficiency, demonstrating viability of the dual-electrode approach. This work establishes that glass-ceramic processing kinetics provide a direct route to compositionally related electrode pairs from a single precursor, with principles that extend to other transition metal systems where controlled crystallization can tune redox windows.
Source: Electrochimica Acta
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,790
Funders: Vetenskapsrådet, Kempestiftelserna
OpenAlex ID: W7222456293