In my opinion, when configure IPP library with opencv,the directory under Bin should be ended in '.dll'. But why the directory of IPP library I downloaded from IBM official website is 'bat' ?
Could you please re-formulate your question? Are you asking why IPP's "bin" directory contain only ".bat" file? You probably mean "ippvars_ia32/ippvars_intel64.bat" files?
The actual DLL location directory is "<Intel Composer directory>\redist\ia32 (or, intel64)\ipp". "Redist" is the directory where all Composer DLLs are located (compiler, IPP, MKL, TBB). The above mentioned .bat files are only to set environment PATH variable properly.