Proton-controlled structural disorder in NASICON cathodes for sodium-ion batteries

Science China Chemistry. 2026.

Wen Y., Lin P., Su X., Li Z., Shi Q., Liu C., Song Z., Liu D., Vasenko A., Smirnov G., Arutyunov K., Liu Y., Ding S., Li L.

Structural disorder is often invoked to explain enhanced ion transport in battery materials, yet in most cases it arises incidentally during synthesis and remains difficult to control. In this work, we show that proton activity during sol–gel processing provides an effective chemical handle to regulate the degree of frozen disorder in NASICON-type cathodes, using Na4MnV(PO4)3 (NVMP) as a representative system. Rather than entering the final lattice, protons is proposed to modulate the relative competition among metal–ligand chelation, hydrolysis, polymerization, and esterification during precursor formation, thereby shaping local structural flexibility prior to crystallization while preserving the integrity of the long-range framework. As a result, an intermediate disorder regime is obtained, which is associated with faster Na⁺ transport without introducing excessive electronic defects or structural instability. Cathodes prepared under these conditions exhibit improved rate capability and stable long-term cycling, retaining 85.6% of their capacity at 5 C after 500 cycles. These results highlight the importance of reaction-pathway control in regulating disorder and suggest a potentially general route for balancing ion mobility and structural stability in polyanionic sodium-ion battery cathodes.

Keywords: cathodes, ионный транспорт, ion transport, Structural Disorder, sodium-ion batteries, Натрий-ионные аккумуляторы, Структурный беспорядок, катоды

Publication based on the results of: Quantum devices and technologies of the new generation (2025)