Abstract Li2MnSiO4 cathode material suffers from structure collapse and thus rapid capacity fading during cycling. Here, we employed the stable [TiO6] ligands as a local pillaring framework to improve the… Click to show full abstract
Abstract Li2MnSiO4 cathode material suffers from structure collapse and thus rapid capacity fading during cycling. Here, we employed the stable [TiO6] ligands as a local pillaring framework to improve the structural stability. Porous Li2MnSi1-xTixO4/C nanoparticles were successfully synthesized by employing SBA-15 as Si source. Rietveld refinement revealed Ti substitution caused the phase composition transition (partial Pmnb to Pmn21 phase), which contributed to higher charge/discharge capacity. XPS confirmed the positions of Ti4+ and the formation of [TiO6] octahedrons. 15 mol% Ti doped sample (S-LMST) showed a highest specific surface area of 114.25 m2 g−1 and delivered a highest initial discharge capacity of 182.7 mAh g−1 under 1.5–4.8 V. Interestingly, S-LMST electrode presented excellent cycling stability, especially retaining ∼94% of initial discharge capacity after 8th cycles, while pristine Li2MnSiO4 only retained ∼55%. Additionally, S-LMST electrode exhibited higher discharge capacity under lower cut-off voltage. The maximal initial discharge capacity can reach to 259.7 mAh g−1 in 1.5–4.6 V. The enhanced cycling stability can be mainly ascribed to the pillaring effect of [TiO6] octahedrons and the decreased charge transfer resistance, as well as the improved Li+ diffusion coefficient due to porous structure.
               
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