Engineering advanced Li1.2V3O8 composite electrodes for lithium batteries

Abstract

International audienc

A Multiscale Description of the Electronic Transport within the Hierarchical Architecture of a Composite Electrode for Lithium Batteries

“…The binder/CB mixture forms a continuous 3D network that connects the surface of Li 1.2 V 3 O 8 particles, [13,15,40] Figure 1b and c. EC þ PC, which is added during the composite electrode preparation and remains in the dried film after the volatile solvent evaporation, forms a miscible blend with PMMA, with a glass transition temperature of 8 8C (at the PMMA/ (EC þ PC) composition studied here). [33] Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) give insufficient information about the electrode architecture with respect to the electrical properties for several reasons. i) At the nanoscale, most of the electronic contacts within the composite electrode can be described by tunnel junctions; [13] because a very small variation in the gap thickness can change a tunnel junction from conductive to non-conductive (or vice-versa), it is very difficult, even with the help of TEM characterization, to understand the variations in the electrical parameters with the composite electrode composition (i.e., with or without EC þ PC) at the nanoscale.…”

“…The composite electrodes studied here were thoroughly characterized in our previous work. [13,15,[30][31][32][33][34][35] They are based on the lithium trivanadate (Li 1.1 V 3 O 8 ) active material, which offers a high theoretical capacity of 330 mA h g À1 and has been investigated as a promising positive electrode AM. [36][37][38][39] Various composite electrodes have been prepared in which the surrounding of the same Li 1.1 V 3 O 8 is changed by pre-plasticizing the poly(methylmethacrylate) (PMMA) binder with ethylene carbonate (EC) and propylene carbonate (PC).…”

Electrochemical Property for the Metal-doped Vanadium Bronze K₂V₈O₂₁ as a Cathode Material of Lithium Battery

“…1,5,6 For the improvement of this low cycle stability of V 2 O 5 , many attempts were carried out and the amorphous state V 2 O 5 7,8 and multiple oxides with potassium or lithium (vanadium bronzes) are known to have high capacity with good cycle stability. [9][10][11][12][13][14][15] Among the vanadium bronzes, Li (or K) V 3 O 8 has been actively investigated by many researchers. [9][10][11] LiV 3 O 8 is reported to show the capacity of 250 mAh/g after 50 cycles charge-discharge.…”

“…[9][10][11][12][13][14][15] Among the vanadium bronzes, Li (or K) V 3 O 8 has been actively investigated by many researchers. [9][10][11] LiV 3 O 8 is reported to show the capacity of 250 mAh/g after 50 cycles charge-discharge. 10,11 In the vanadium bronzes, there are other phases that are known to be stable.…”

“…[9][10][11] LiV 3 O 8 is reported to show the capacity of 250 mAh/g after 50 cycles charge-discharge. 10,11 In the vanadium bronzes, there are other phases that are known to be stable. K 2 V 8 O 21 is one of the stable phases and has higher theoretical capacity than KV 3 O 8 phase, 261 mAh/g for K 2 V 8 O 21 , 251 mAh/g for KV 3 O 8 until all vanadium ions are reduced to +4, because of the lower ratio of potassium to vanadium.…”