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Challenges Of Li Technology

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Now, the picture is much more clearer. Although other factors such as temperature, through the Arrhenius formula , impacts the transition of lithium ions form cathode to anode or vice versa, a sufficient qualitative and quantitative analysis have been provided to answer the question of “how a LIB works” from a physical point of view. The analysis of electron migration is as vast and multi-dimensional as the lithium ion migration however, due to the detailed discussion of such migrations in any modern physics book (mainly the impact of fermi levels on the electron conductivity and mobility), I shall avoid analyzing this concept entirely. The lithium ions behavior was discussed since it is lesser known than the electrons behavior. In the …show more content…

The new market demands expect three major characteristics from LIBs: “high specific energy Li rechargeable cells, high specific power Li rechargeable cells, and Li rechargeable thin film and flexible cells [ ].

Since the specific energy of a battery is determined by the product of the operating voltage and specific capacity, in order to meet the demanded characteristic of higher specific energy; higher operating voltage, and higher specific capacity need to be achieved. The higher operating voltage can be reached by finding cathodes and anodes such that their average difference of chemical potential is as large as possible while the safety is assured. Conventional cathode and anode materials used in LIB cells could only have a maximum operating voltage of about 4V per cell which needs to be higher if one wants to avoid using numerous LIB cells in series and parallel to meet the high voltage need of about 400 volts for electric cars for example. Similarity, the demanded characteristic of high specific capacity is reached if more efficient and chemically suitable materials other than LiCoO2 and graphite are used in a LIB cell.
For satisfying the need for high power LIBs, one can clearly see what the requirements are by recalling the equation of power: . Higher operating voltage and less internal resistance, which is determined mostly by how the electrolyte behaves in a cell, is needed to maximize the power output per cell of a LIB.
And finally,

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