I don't have good news. Dell doesn't carry batteries for a system more than a few years old. The next place to check is Parts-People, but I checked and they don't have any for your model.  Your system is 10 or 11 years old, so it will be impossible to find any genuine Dell batteries. You would have to buy a battery from elsewhere. It will not be a Dell battery. It might work, or it might not, or it might fail before long. If you buy such a battery, make sure to choose a vendor that has a good return/refund policy.
My existing battery stopped working so need to replace it. I do not find the battery in Dell website for the model Inspiron 14R 4010. Can someone tell me the compatible battery  for Inspiron 14R 4010? You suggestions are much appreciated.  Thanks. 
Compatible battery for Inspiron 14R