Crosslinked polymer electrolyte
A composite electrolyte can include a crosslinked polymer formed from telechelic precursor polymers having at least two photoactivatable end functional groups and a molecular weight before crosslinking of between about 1,000 and 1,000,000 Daltons (Da); and a lithium (Li) salt. Electrochemical cells and batteries including such electrolytes are also disclosed, along with various methods of manufacture.
1. A composite electrolyte comprising:
a crosslinked polymer formed from telechelic precursor polymers having at least two photoactivatable end functional groups, wherein the telechelic precursor polymers have a molecular weight before crosslinking of between 1,000 and 1,000,000 Daltons (Da); and a lithium (Li) salt, wherein the telechelic precursor polymers comprise diazido-PEO; and
an ionic liquid solvent.
2. The composite electrolyte of claim 1 , wherein the telechelic precursor polymers have the same molecular weight.
3. The composite electrolyte of claim 1 , wherein the telechelic precursor polymers have a molecular weight before crosslinking of 20,000 Daltons and a constant nanopore size of 200 nm.
4. The composite electrolyte of claim 1 , wherein the crosslinked polymer forms a constant nanopore structure.
5. The composite electrolyte of claim 1 , further comprising oxide nanoparticles of size such that at least one dimension is <1 μm.
6. The composite electrolyte of claim 1 , wherein the telechelic precursor polymers have the same molecular weight and composition.
7. An electrochemical cell, comprising:
an anode that can accommodate lithium (Li);
a cathode; and
a composite electrolyte comprising an ionic liquid solvent and having a crosslinked polymer formed from a precursor telechelic polymer with at least two photoactivatable end groups, wherein the precursor telechelic polymers have a molecular weight between 1,000 and 1,000,000 Daltons, wherein the telechelic precursor polymers comprise diazido-PEO.
8. A battery, comprising:
a housing formed to enclose one or more electrochemical cells; wherein
each electrochemical cell includes an anode comprising lithium (Li);
a cathode; and
a composite electrolyte comprising an ionic liquid solvent and having a crosslinked polymer formed from a precursor telechelic polymer with at least two photoactivatable end groups, wherein the precursor telechelic polymers have a molecular weight between 1,000 and 1,000,000 Daltons, wherein the telechelic precursor polymers comprise diazido-PEO.
9. A method of making an electrolyte comprising the steps of:
introducing a solution of lithium (Li) salt and ionic liquid to a mixture comprising telechelic precursor polymers having at least two photoactivatable end functional groups, wherein the telechelic precursor polymers comprise diazido-PEO; and
forming a crosslinked polymer from a precursor telechelic polymer by photochemical reaction.
10. The method of claim 9 , wherein the introducing step is followed by a heating and homogenization step to form a paste.
11. The method of claim 9 , wherein the step of forming a crosslinked polymer electrolyte further comprises positioning the precursor mixture on an electrode or conductive structure prior to forming the crosslinked polymer by photochemical reaction.
12. The method of claim 9 , wherein the introduction step is performed after the photochemical reaction step.
13. A method of making an electrolyte, comprising the steps of:
providing a precursor telechelic polymer with at least two photoactivatable end groups; and
forming a crosslinked polymer by photochemically reacting the precursor telechelic polymer in the presence of a lithium (Li) salt, an ionic liquid, and solid particles, wherein the telechelic precursor polymers comprise diazido-PEO.
14. The method of claim 13 , wherein the precursor telechelic polymer is blended from polymeric materials having distinct molecular weights.
15. The method of claim 13 , wherein solid particles are sized to have at least one dimension less than 1 micron.