Lithium-rich layered oxide

Lithium-Rich Layered Oxide (Li2Mn03-LiM02).126... 

K.A. Jarvis, Z.Q. Deng, L.R Allard, A. Manthiram and RJ. Ferreira, Atomic structure of a lithium-rich layered oxide material for lithium-ion batteries Evidence of a solid solution, Chem. Mater. 23, 2011,3614—3621. 

TABLE 17.3 Summary of the Selected, Prominent Works Dedicated to the Lithium-Rich Layered Transition Metal Oxides... 

It has been reported that the Li-rich layered oxide material Li2Mn03 LiM02 (M = Co, Ni) exhibits a discharge capacity of >280 mAh/g when operated above 4.7 V, which is about twice that of current commercial positive electrode materials for lithium-ion batteries, making it a promising candidate for a positive electrode material. 

DBMS) [ARM 06] nevertheless, the quantity of gas detected was not sufficient to compensate for the total quantity of lithium deintercalated on the plateau . It has been shown that this unusual mechanism arose due to the reversible participation of the oxygen anion in the redox processes. This original mechanism, demonstrated for the first time for layered oxides, is possible due to the particular composition of these Li- and Mn-rich materials the hybridization of transition metals nd levels and anions 2p levels leads to a mixed redox process involving both the cations and the anions [KOG 13a, SAT 13a, SAT 13b]. This mechanism, responsible for the exceptional reversible capacity these materials deliver, is enhanced for transition metals that are highly oxidized and electronegative (Figure 2.13). 

The main positive electrode materials for lithium-ion batteries, LiCo02, LiNi02, LiMn204, and LiFeP04, were discussed in Chapters 2 through 5. In this chapter, several other important positive electrode materials will be discussed, including Li-rich layered Mn oxides, phosphates, sulfates, silicates, borates, titanates, V2O5, and other oxides [1]. 

Porous carbons and nanotubes have attracted considerable attention in relation to such practical issues as hydrogen storage, lithium batteries, and supercapacitors. In general, the electrochemical behavior of porous carbons and CNTs solely consists of double-layer charging processes with small or zero contribution of faradaic pseudocapacitance of surface oxide functionalities. This is in sharp contrast with the rich electrochemistry of fullerenes. 

A further phenomenon, as yet unexplained, can also be seen following the same PAA pretreatment of the alloy. Fig. 19 shows the unexpectedly high distribution of copper-rich intermetaUics at the aluminium boundary layer — the black inclusions at the base of the oxide film. Their chemical composition — essentiaUy copper with some lithium — has been confirmed by both EDX (energy dispersive X-ray) and EELS (electron energy loss spectroscopy) analysis [51]. 

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