You want to use a batch jobs so batch jobs should not have password embedded in the command line or script.
You can use Oracle Basic authentication methods for implementing no password login credentials.
sqlplus /nolog
conn / as sysdba
show parameters OS_AUTHENT_PREFIX
os_authent_prefix ops$
Alter system set OS_AUTHENT_PREFIX=' ' scope=spfile;
shu immediate
startup
conn system/oracle
creed user zekeriya identified externally;
grant create session,resource to zekeriya;
operating system zekeriya is OS user
oracle$ su - zekeriya
password:****
zekeriya$ sqlplus /
select * from dual;
