It looks like you have 2 problems. The first is some issue with Invoke-ps2exe. For that one, I would think that you need to provide the .exe file name and not just the folder name in the Target file field.

If Powershell is not able to successfully execute your .ps1 script, then it may be that the encoding of the .ps1 file is not able to store whatever that last character in the password is. When using notepad, do a SaveAs and make sure that the encoding is set to either UTF-8 or "UTF-8 with BOM".
When testing, modify "bl.bat" to just do something simple like "timeout.exe /t 10" instead of any Bitlocker process.
If Powershell is able to execute the .ps1 file, then the most obvious conclusion would be that PS2EXE is unable to handle that last character.
In that case, try changing the password.
