Driving 7segments display with CD4511
I assume you mean LED rather than LCD, as the 4511 is inappropriate for LCD and your schematic shows an LED display. If the actual circuit is a single LED per segment you would be better off adding a regulator to the 4511, but I'll assume it's a &quot;big digit&quot; type with several series LEDs per segment.
The input voltage should be a minimum of about 70% of Vdd, so for a 7.4V Vdd you would need a bit more than 5V in.
Your level shifter will not really work- try this:



simulate this circuit &ndash; Schematic created using CircuitLab