In this installment of the “Looking at Patent Law” series, we present a case study of the prosecution events of U.S. Patent No. 9,559,375 directed towards “Iron Flow Battery”. This invention aligns with several divisions of the Electrochemical Society (ECS), including Industrial Electrochemistry and Electrochemical Engineering (IE&EE), Battery (BATT), Energy Technology (ETD) and Electrodeposition (ELDP). The case study begins with a brief synopsis of the background of the invention followed by 1) summary of key drawings and the specification of the invention, 2) inventor assignment and power of attorney designations, 3) submission of the Invention Disclosure Statement (IDS) and associated Duty of Candor, 4) summary of the non-final office action (NF-OA) and rejection, and 5) applicant response and allowance of the patent application. The case study illustrates overcoming lack of “novelty” and “obviousness” rejections by combining the limitation of dependent claims with the independent claim. With this case study, we hope to de-mystify the patent prosecution process and better prepare electrochemical and solid-state scientists, engineers and technologists to interact with their patent counsel regarding their inventions.