Study On Lithium Metal Anode Material Of High Specific Energy Lithium Secondary Battery

Lithium metal is one of the electrode materials those have the highest specific mass energy, and the lithium secondary battery with lithium metal anode always attracts people's attentions. Whileas, before the commodity of lithium secondary battery, it is the dissatisfactory cycleability and safety of lithium metal anode that must be resolved firstly. The present studies have proved that the most important factor which influences the performances of lithium metal anode in battery is the solid electrolyte interphase interface-film (SEI film) on lithium anode. And how to make lithium metal anode have a SEI film with favorable composition and stable configuration, or make the SEI film have better stability, is the key to improve the electrochemistry performances of lithium metal anode in lithium secondary battery.Aiming to the above goals, two original modifying ways of lithium electrode were suggested to make lithium electrode have a more stable SEI film. One was using the cyclic ether to pretreat the lithium metal electrode. And a favorable surface SEI film was wished to form on the lithium metal, to enhance the interface stability of lithium electrode and the cycleability of lithium battery. The other was to research new Li-Al solid solution alloy material and use it as anode in lithium battery. By the trace alloy component, aluminum, doping in lithium metal, it was hoped to improve the SEI film stability of lithium/electrolyte interface and consequentially enhance the performances of lithium anode. Meanwhile, different form the previously studied LiAl alloy that had very high content of aluminum, such alloy should not decrease the mass specific energy and electrochemical potential of lithium electrode. In the work, it was systemically studied that the effects of two suggested modifying ways on electrochemical characteristics of lithium metal electrode and its behaviors in lithium cell. Finally, the action mechanisms of these two modifying ways were analyzed.Through the study on pretreatment effects of different cyclic ether on lithium electrode, it was found that 1,4-dioxane (DOA) and 1,3-dioxolane (DOL), both could form a favorable passivating SEI film on lithium electrode surface through...