“Three‐in‐One:” A New 3D Hybrid Structure of Li₃V₂(PO₄)₃ @ Biomorphic Carbon for High‐Rate and Low‐Temperature Lithium Ion Batteries

Abstract

material. But the high cost, high toxic, and safety problems hampered its widespread applications. [4] Recently, lithium-based phosphates such as LiMPO 4 (M = Co, Mn, Fe) and Li 3 M 2 (PO 4 ) 3 (M = V, Fe) have been considered as the most promising cathode materials for the next generation LIBs. [5][6][7] These polyanion materials are constructed by the [PO 4 ] 3− anion groups, which help to stabilize the crystal structure of the materials. The oxygen atoms are fixed in the [PO 4 ] 3− group, thus limiting the release of the oxygen atoms and leading to good thermal stability. [8,9] Among various polyanion cathode materials, monoclinic Li 3 V 2 (PO 4 ) 3 (LVP) is a highly promising one for its high theoretical specific capacity, high operating voltage, and high cycling stability. [10][11][12][13] However, the [VO 6 ] octahedra in LVP are separated with each other by [PO 4 ] 3− groups, resulting in low intrinsic electronic conductivity, and restrict the widespread application of the LVP. [14][15][16] Carbon coating is an effective way to improve the electronic conductivity of the LVP. In previous reports, different kinds of carbon sources have been coated on the surface of the LVP to enhance its electronic conductivity. However, too thick a carbon layer will act as a barrier for Li + diffusion, thus limiting the electrochemical performance of the material, especially at high charge-discharge rates. [17] As a comparison, 3D carbon structures with continuous porous channels showed great superiority. [18] The abundant interconnected porous channels can offer sufficient contact area between the electrolyte and the electrode, resulting in fast electron/ion transport. Moreover, the porous structures can relieve volume expansion during the charge/discharge process and enhance the cycle stability. However, the construction of the 3D hybrid architectures is a complicated process and usually needs a high-cost template, which is unfavorable for applications in large scales. Herein we report a facile method for constructing 3D hybrid architectures of LVP @ biomass-derived porous carbon (LVP@HPBC). The 3D hybrid carbon architecture was made from natural-biomass agaric which has a unique inner structure. There are gelatinous layers on one side of the agaric, while the other side is covered by long beards. After calcination, the gelatinous layer is carbonated to a 2D carbon layer and the long beard is transformed Li 3 V 2 (PO 4 ) 3 with high specific capacity and high operating potential has been considered as a promising cathode for the next generation lithium ion batteries (LIBs). But the low electronic conductivity restricts its practical applications. Here, a rational design of 3D hybrid structures of Li 3 V 2 (PO 4 ) 3 @ biomorphic carbon is presented. The 3D hybrid structures built from 0D, 1D, and 2D composites are carbonized from biomorphic carbon, namely, "three-in-one." The synergistic effects of the carbon with different dimensions provide high electronic conductivity and good structural stability. In addition, abundan...

Zn-Ion Batteries: Boosting the Rate Capability and Low-temperature Performance by Combining Structure and Morphology Engineering

“…The calculation details are listed in the Supporting Information (Figure S8 and Table S2). The reason may be related to the ion diffusion and zinc ion intercalation/deintercalation sites, but is not clear and needs further study. − The cycle stability is also impressive. As shown in Figures e and S9, the capacity retention is higher than 86% after 700 cycles at 2C, 78% after 2000 cycles at 5C, and 83% after 2000 cycles at 10C.…”

Nanostructured Li3V2(PO4)3 Cathodes

“…Natural‐biomass agaric with a unique inner structure (i.e., gelatinous layers on one side and long beards on the other) was proposed to construct the 3D hybrid architectures of Li 3 V 2 (PO 4 ) 3 @biomass‐derived porous carbon (Li 3 V 2 (PO 4 ) 3 @HPBC) . As illustrated in Figure A, the agaric could soak the Li 3 V 2 (PO 4 ) 3 precursor solution (including the carbon source of oxalic acid), and the subsequent calcination process converted gelatinous layers to 2D carbon layers, long beards to 1D carbon tubes, and oxalic acid + Li 3 V 2 (PO 4 ) 3 precursor to 0D carbon‐coated Li 3 V 2 (PO 4 ) 3 NPs.…”

“…F) Cycle performance of Li 3 V 2 (PO 4 ) 3 @HPBC/Li 4 Ti 5 O 12 full battery. Reproduced with permission . Copyright 2017, Wiley‐VCH.…”

Facile synthesis of Li3V2(PO4)3/C cathode material for lithium-ion battery via freeze-drying

“…After that, Tu and co-workers [15] employed PVA-124 as carbon sources to prepare the Li 3 V 2 (PO 4 ) 3 /C composite with a simple carbon-thermal reduction method; this composite exhibited a high initial discharge capacity at low and high temperature. In recently, Zhang and co-workers [16] properties. Chen and co-workers [17] made use of graphene as a carbon source to synthesize grapheme-modified Li 3 V 2 (PO 4 ) 3 by a two-step solid-state reaction process; this composite showed excellent rate performance with a discharge capacity of 112.7 mAh/g at a current density of 20 C. More recently, our group [18] used citric acid as a carbon source to synthesize Li 3 V 2 (PO 4 ) 3 /C via a wetchemical coordination method, which exhibited superb rate performance and cyclic stability.…”