Na<sub>3</sub>MnTi(PO<sub>4</sub>)<sub>3</sub>/C Nanofiber Free-Standing Electrode for Long-Cycling-Life Sodium-Ion Batteries
Debora Maria Conti,
Claudia Urru,
Giovanna Bruni,
Pietro Galinetto,
Benedetta Albini,
Vittorio Berbenni,
Alessandro Girella,
Doretta Capsoni
Affiliations
Debora Maria Conti
Department of Chemistry, Physical Chemistry Section & C.S.G.I. (Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase), University of Pavia, Via Taramelli 16, 27100 Pavia, Italy
Claudia Urru
Department of Chemistry, Physical Chemistry Section & C.S.G.I. (Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase), University of Pavia, Via Taramelli 16, 27100 Pavia, Italy
Giovanna Bruni
Department of Chemistry, Physical Chemistry Section & C.S.G.I. (Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase), University of Pavia, Via Taramelli 16, 27100 Pavia, Italy
Pietro Galinetto
Department of Physics, University of Pavia, Via Bassi 6, 27100 Pavia, Italy
Benedetta Albini
Department of Physics, University of Pavia, Via Bassi 6, 27100 Pavia, Italy
Vittorio Berbenni
Department of Chemistry, Physical Chemistry Section & C.S.G.I. (Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase), University of Pavia, Via Taramelli 16, 27100 Pavia, Italy
Alessandro Girella
Department of Chemistry, Physical Chemistry Section & C.S.G.I. (Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase), University of Pavia, Via Taramelli 16, 27100 Pavia, Italy
Doretta Capsoni
Department of Chemistry, Physical Chemistry Section & C.S.G.I. (Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase), University of Pavia, Via Taramelli 16, 27100 Pavia, Italy
Self-standing Na3MnTi(PO4)3/carbon nanofiber (CNF) electrodes are successfully synthesized by electrospinning. A pre-synthesized Na3MnTi(PO4)3 is dispersed in a polymeric solution, and the electrospun product is heat-treated at 750 °C in nitrogen flow to obtain active material/CNF electrodes. The active material loading is 10 wt%. SEM, TEM, and EDS analyses demonstrate that the Na3MnTi(PO4)3 particles are homogeneously spread into and within CNFs. The loaded Na3MnTi(PO4)3 displays the NASICON structure; compared to the pre-synthesized material, the higher sintering temperature (750 °C) used to obtain conductive CNFs leads to cell shrinkage along the a axis. The electrochemical performances are appealing compared to a tape-casted electrode appositely prepared. The self-standing electrode displays an initial discharge capacity of 124.38 mAh/g at 0.05C, completely recovered after cycling at an increasing C-rate and a coulombic efficiency ≥98%. The capacity value at 20C is 77.60 mAh/g, and the self-standing electrode exhibits good cycling performance and a capacity retention of 59.6% after 1000 cycles at 1C. Specific capacities of 33.6, 22.6, and 17.3 mAh/g are obtained by further cycling at 5C, 10C, and 20C, and the initial capacity is completely recovered after 1350 cycles. The promising capacity values and cycling performance are due to the easy electrolyte diffusion and contact with the active material, offered by the porous nature of non-woven nanofibers.
