Polymer nanocomposites for lithium battery applications
A single ion-conducting nanocomposite of a substantially amorphous polyethylene ether and a negatively charged synthetic smectite clay useful as an electrolyte. Excess SiO 2 improves conductivity and when combined with synthetic hectorite forms superior membranes for batteries. A method of making membranes is also disclosed.
1 - 19 . (canceled)
20 . A single ion-conducting polymer electrolyte, comprising a nanocomposite of a substantially amorphous polyethylene ether intercalated in a negatively charged synthetic phyllosilicate clay having excess SiO 2 therein.
21 . The single ion-conducting polymer electrolyte of claim 20 , wherein said synthetic phyllosilicate clay has platelets having a thickness in the range of from about 15 to about 40 nanometers.
22 . The single ion-conducting polymer electrolyte of claim 21 , wherein said excess SiO 2 is present in the range of from about 15% to abut 25%.
23 . The single ion-conducting polymer electrolyte of claim 22 , wherein said excess SiO 2 is present in an amount of about 20%.
24 . The single ion-conducting polymer electrolyte of claim 22 , wherein said phyllosilicate clay is a hectorite.
25 . The single ion-conducting polymer electrolyte of claim 24 , wherein said excess SiO 2 is present is in the form of spheres about 20 nanometers in diameter.
26 . The single ion-conducting polymer electrolyte of claim 25 , wherein the mass ratio of polyethylene ether to hectorite clay is in the range of from about 0.5:1 to about 3:1.
27 . The single ion-conducting polymer electrolyte of claim 26 , wherein said electrolyte is in the form of a membrane having a thickness in the range of from about 40 to about 60 micrometers.
28 . The single ion-conducting polymer electrolyte membrane of claim 27 , wherein said membrane is on a backing material of glass or silicon.
29 . The single ion-conducting polymer electrolyte membrane of claim 28 , wherein said negatively charged hectorite clay has Li+ ions therein.
30 . The single ion-conducting polymer electrolyte membrane of claim 29 , wherein at least a portion of said polyethylene ether is polyethylene oxide having a molecular weight between about 80,000 and about 250,000.
31 . The single ion-conducting polymer electrolyte membrane of claim 30 , wherein the mass ratio of polyethylene oxide to clay is in the range of from about 0.5:1 to about 1.5:1.
32 . The single ion-conducting polymer electrolyte membrane of claim 31 , wherein the ion transport number is greater than 9.0.
33 . A single lithium-ion conducting polymer electrolyte membrane, comprising a nanocomposite of substantially amorphous polyethylene oxide intercalated in a negatively charged synthetic phyllosilicate clay having not less than about 15% excess SiO 2 .
34 . The single lithium-ion conducting polymer electrolyte membrane of claim 33 , wherein said phyllosilicate clay has platelets having a thickness in the range of from about 15 to about 40 nanometers and the excess SiO 2 is in the form of spheres about 20 nanometers in diameter.
35 . The single lithium-ion conducting polymer electrolyte membrane of claim 34 , wherein the lithium ion transport number is greater than 90.
36 . The single lithium-ion conducting polymer electrolyte membrane of claim 35 and further including a substrate carrying said membrane.
37 . The single lithium-ion conducting polymer electrolyte membrane of claim 36 , wherein said substrate is silicon or a glass.
38 . The single lithium-ion conducting polymer electrolyte membrane of claim 37 , wherein the membrane has a thickness in the range from about 40 to about 60 micrometers; and the mass ratio of polyethylene oxide to clay is in the range of from abut 0.5:1 to about 1.5:1.
39 - 50 . (canceled)