Surface treatment for lithium metal anodes
A method of preparing a lithium metal electrode for an electrochemical cell, such as a lithium metal battery, includes introducing a treatment gas into a chamber including an electrode precursor. The treatment gas may include a reactant gas and/or a plasma. The electrode precursor includes lithium metal and a passivation layer. The method further includes forming the lithium metal electrode by contacting the treatment gas with the passivation layer to remove at least a portion of the passivation layer. The present disclosure also provides pretreated electrodes and electrode assemblies.
1 . A method of preparing a lithium metal electrode for an electrochemical cell, the method comprising:
introducing a treatment gas into a chamber including an electrode precursor, the electrode precursor including lithium metal and a passivation layer;
heating the electrode precursor by a temperature-controlled stage to increase a temperature of the electrode precursor; and
forming the lithium metal electrode by contacting the treatment gas with the passivation layer to remove at least a portion of the passivation layer.
2 . The method of claim 1 , wherein the treatment gas is a single treatment gas.
3 . The method of claim 1 , wherein the treatment gas is a reactant configured to react with at least a portion of the passivation layer.
4 . The method of claim 3 , wherein the reactant is configured to react with at least a portion of the passivation layer to change a composition of the passivation layer.
5 . The method of claim 3 , wherein the reactant is selected from the group consisting of: trimethylaluminum (TMA); trimethyl phosphate (TMPO), nitrogen (N 2 ), water (H 2 O), oxygen (O 2 ), ozone (O 3 ), triethylphosphate (TEPO), titanium isopropoxide (TTIP), or any combination thereof.
6 . The method of claim 3 , wherein the reactant is configured to react with at least a portion of the passivation layer to replace a functional group on a surface of the lithium metal electrode.
7 . The method of claim 1 , wherein the treatment gas is a plasma configured to mechanically engage the passivation layer to remove at least a portion of the passivation layer.
8 . The method of claim 7 , the introducing includes generating the plasma from a compound selected from the group consisting of: Ar, O 2 , O 3 , N 2 , NH 3 , or any combination thereof.
9 . The method of claim 1 , wherein a temperature inside the chamber is greater than or equal to about 20° C. to less than or equal to about 90° C.
10 . The method of claim 1 , wherein the chamber is substantially free of air.
11 . The method of claim 1 , wherein the treatment case includes a first treatment gas including a reactant and a second treatment gas including a plasma.
12 . The method of claim 1 , wherein the lithium metal electrode is configured to be in direct contact with a gel polymer electrolyte.
13 . The method of claim 1 , wherein the lithium metal electrode is configured to be in direct contact with a liquid electrolyte having a viscosity of greater than or equal to about 0.5 cP.
14 . The method of claim 1 , wherein a surface of the lithium metal electrode is configured to have a contact angle with an electrolyte of greater than or equal to about 0° to less than or equal to about 90°.
15 . The method of claim 1 , wherein an electrochemical assembly including the lithium metal electrode is configured to have an areal discharge capacity of greater than or equal to about 1 mAh/cm 2 to less than or equal to about 5 mAh/cm 2 .
16 . A method of preparing a lithium metal electrode assembly for an electrochemical cell, the method comprising:
introducing a treatment gas into a chamber including an electrode precursor, the electrode precursor including lithium metal and a passivation layer;
heating the electrode precursor by a temperature-controlled stage to increase a temperature of the electrode precursor;
preparing the lithium metal electrode by contacting the treatment gas with the passivation layer to remove at least a portion of the passivation layer; and
disposing an electrolyte in direct contact with the lithium metal on a surface of the lithium metal electrode.
17 . The method of claim 16 , wherein the electrolyte is a gel polymer electrolyte.
18 . The method of claim 16 , wherein the disposing includes,
disposing a layer on the surface, the layer including a monomer and an initiator,
crosslinking the monomer to form the gel polymer electrolyte by exposing the layer to UV radiation.
19 . The method of claim 16 , wherein the electrolyte is a liquid electrolyte having a viscosity of greater than or equal to about 0.5 cP.