Synthesis and characterization of LiTi2(PO4)3/C nanocomposite as lithium intercalation electrode materials

Cation/Anion Doping Strategy for Na4MnV(PO4)3 with High Energy Density and Long Cycling Life through Construction by Aspergillus niger

Na4MnV(PO4)3 (NMVP) has gained attention for its high redox potential, good cycling stability, and competitive price but suffers from poor intrinsic electronic conductivity and Jahn-Teller effect from Mn3+. In this work, cation/anion doping strategy was used for Aspergillus niger-bioderived carbon-coated NMVP (NMVP/AN) to improve the structural stability and electrochemical performance, where Al3+ doping inhibited the dissolution of Mn and enhanced the Mn3+/Mn2+ redox pair activity; besides, F- doping not only weakens the Na2-O bond but also endows the hierarchical and porous structure of NMVP/AN, which led to a more rapid and fluid transfer of Na+. The elaborately designed Na3.9Mn0.9Al0.1V(PO4)3/AN (NMAVP/AN) exhibits 105.9 mA h g-1 at 0.5 C, and the as-prepared Na3.1MnV(PO3.7F0.3)3/AN (NMVPF/AN) delivers 104.1 mA h g-1 at 5 C. Further demonstration of the hard carbon//NMAVP/AN full cell manifests the good potential of Al3+-doped NMVP/AN for practical applications (100.6 mA h g-1 at 1 C). These findings open up the possibility of unlocking the high-performance Na superionic conductor (NASICON).

Yeast Template-Derived Multielectron Reaction NASICON Structure Na3MnTi(PO4)3 for High-Performance Sodium-Ion Batteries

The sodium super ion conductor (NASICON) structure materials are essential for sodium-ion batteries (SIBs) due to their robust crystal structure, excellent ionic conductivity, and flexibility to regulate element and valence. However, the poor electronic conductivity and inferior energy density caused by the nature of these materials have always been obstacles to commercialization. Herein, using yeast as a template to derive NASICON structure Na₃MnTi(PO₄)₃ (NMTP) materials (noted as Yeast@NMTP/C) is presented. The Yeast@NMTP/C material retains the microsphere morphology of the yeast template and not only controls the particle size (around 2 μm) to shorten the Na⁺ diffusion pathways but also improves the electronic conductivity to optimize the electrochemical kinetics. The Yeast@NMTP/C cathode delivers reversible multielectron redox reactions including Ti^4+/3+, Mn^3+/2+, and Mn^4+/3+ and exhibits a high capacity of 108.5 mAh g^-1 with a 79.2% capacity retention after 1000 cycles at a 2C rate. The sodium storage mechanism of Yeast@NMTP/C reveals that the addition of Ti^4+/3+ redox plays a key role in improving the Na⁺ diffusion kinetics, and both solid-solution and two-phase reactions take place during the desodiation and sodiation process. Additionally, the high-rate and long-span cycle performance of Yeast@NMTP/C at 10C is ascribed to contribute to pseudocapacitance.

Enhanced Electrochemical Performance of Fast Ionic Conductor LiTi2(PO4)3-Coated LiNi1/3Co1/3Mn1/3O2 Cathode Material

Layered LiNi_1/3Co_1/3Mn_1/3O₂ (NCM333) is successfully coated by fast ionic conductor LiTi₂(PO₄)₃ (LTP) via a wet chemical method. The effects of LTP on the physicochemical properties and electrochemical performance are studied. The results reveal that a highly layered structure of NCM333 can be well maintained with less cation mixing after LTP coating. LTP of about 5 nm thickness is coated on the surface of NCM333. Such an LTP coating layer can effectively suppress the side reactions between NCM333 and electrolyte but will not hinder the lithium ion transmission. As a result, LTP-coated NCM333 owns an improved capability and cyclic performance, for example, NCM333/LTP delivers an initial capacity as high as 121.0 mA h g^-1 with a capacity retention ratio of 82.3% after 200 cycles at 10 C, whereas NCM333 only has an initial capacity of 120.4 mA h g^-1 with a very low capacity retention ratio of 66.4%. This method of using a fast ionic conductor like LTP as a coating material may provide a simple and effective strategy to modify those electrode materials with poor cyclic performance.

Touching the theoretical capacity: synthesizing cubic LiTi2(PO4)3/C nanocomposites for high-performance lithium-ion battery

A cubic LiTi2(PO4)3/C composite is successfully prepared via a simple solvothermal method and further glucose-pyrolysis treatment. The as-fabricated LTP/C material delivers an ultra-high reversible capacity of 144 mA h g-1 at 0.2C rate, which is the highest ever reported, and shows considerable performance improvement compared with before. Combining this with the stable cycling performance and high rate capability, such material has a promising future in practical application.

Low-temperature synthesis of macroporous LiTi2(PO4)3/C with superior lithium storage properties

A macroporous LiTi₂(PO₄)₃/C nanocomposite is prepared using a calcination-temperature as low as 550 °C, and exhibits superior cycle performance in lithium batteries.

LiTi2(PO4)3/reduced graphene oxide nanocomposite with enhanced electrochemical performance for lithium-ion batteries

NASICON-structured LiTi₂(PO₄)₃/rGO nanocomposite was successfully fabricated by in situ synthesis of a Li–Ti–P–O/rGO precursor by microwave-assisted one-pot method followed by calcination heat treatment. Electrodes prepared from the nanocomposites provide excellent cycling performance and rate capability, indicating great potential for their use in LIBs.