Nickel Iron (NiFe) Battery Design

Looking for a design electrical/mechanical engineer to design in CAD a workable nickel-iron (NiFe) battery. The battery has to be able to withstand the rigors of the outside weather, in a battery bank (off-grid) solar panel charged configuration. I am seeking to build the batteries myself, hence don't have the funding to mass produce using outsourcing corporations. I can't discuss budgets, simply put, I am aiming to find out the likelihood of success in having the battery designed the way I want, hence I am not seeking feasibility studies or flow diagrams of project considerations. The initial design brief: The outer battery casing has to be able to withstand weight placed on top and the side of the battery (in this instance the solar panels), with the provision, all be a simple nut welded on either side/top of the battery case to fix onto a frame. The outer casing to be made of stainless steel throughout, stainless steel being my preference, hence not rust. The inner insulator if possible to be made out of, off the shelf non-perishable material. This I am not sure about, perhaps a 3d printed plastic insulator...? An example of the type of design I am seeking is attached infographic advert from a Ni-Fe battery manufactured years ago. The typical size I am requiring is approx. 100mm x 100mm x 100mm, though this is a broad estimation and not an absolute, hence your design input is required for best size around this dimension. Using this off the shelf stainless steel. [login to view URL] Similar in size to the 22Ah 1.2v battery size as in this link or the attached file - For illustration only, must not be copied click on images to see : [login to view URL] What is important, is that I am not seeking an advanced design, or for that a high energy efficient design. I am looking for a rudimentary, basic as possible battery that has basic anode/cathode nickel-iron plates/possibly tubes inside which if needed can be disassembled/replaced for long-term maintenance, though this shouldn't be actually needed owing to the proven longevity of NiFe batteries. (20 -100 years - 1912 Detroit Electric Car with NiFe Battery still functioning after 100 years) A very basic relief valve (for hydrogen gas emitted from the battery) using off the shelf repurposed parts, if possible the valve having a provision for a pipe for an additional top up water/ electrolyte holding tank attached to the bank, as mentioned the batteries will be outside hence over-engineering the battery for strength is key to what I am looking for, the weight of the battery is not an issue, strength, reliability of the connections within the battery internal and externally are very important. Its charging/power output is to whatever the best you can design. Your design would be in CAD, with all the build information required to make the battery work. A little about myself: I am not a 'business corporation' that is, I am a one man self-employed individual, I don't have an office building, or staff working for me. I drive a taxi cab here in the UK to earn a living, however, I have a previous technical background (ex College lecturer I.T), I am willing to pay a fixed price for the design work I need. If you are a newly qualified engineer you are welcome to get in touch or even an expert that has a passion for designing something unique. I am very flexible with regards to time limits.