s(methoxyethoxyethoxy)phosphazene]), an oozy, thick oil. The resulting solid, pliable membrane lets positively charged lithium ions pass through to create the electrical circuit that powers the battery but rebuffs negatively charged electrons. This keeps the battery from running down while it sits on the shelf-overcoming a major battery-life storage problem. For years, rechargeable lithium battery performance has been disappoint- ing because the batteries needed recharging every few days. After conquering the discharge challenge, the team attacked the need for greater battery power to be commercially competitive. Their membrane didn't allow sufficient passage of lithium ions to produce enough power, SO they needed to under- ENERGY TO GO-POWER GENERATION stand exactly how the lithium ions move through the membrane on a molec- ular level. First, they analyzed the MEEP membrane using nuclear magnetic resonance-the equivalent of a hospital MRI-to zero in on the best lithium ion travel routes. The results supported the team's suspicion that the lithium ions travel along the membrane's "backbone." The MEEP membrane has a backbone of alternating phosphorus and nitrogen molecules, with oxygen- laden "ribs" attached to the phosphorus molecules. Further analysis with infrared and raman spectroscopy (techniques that measure vibrational frequencies and the bonds between different nuclei) helped confirm that the lithium ions are most mobile when interacting with nitrogen. Lithium prefers to nestle into a "pocket" created by a nitrogen mol- ecule on the bottom with oxygen molecules from a MEEP rib on either side. Armed with this new understanding of how lithium moves through the solid MEEP membrane, the team starting making new membrane versions to opti- mize lithium ion flow. This should make the team's lithium batteries much more powerful. The team's research results are a major departure from the conventionally accepted explanation of lithium ion transport that proposed the lithium/MEEP transport mechanism as jumping from o