Shareholders, and international and domestic institutions, have pumped in an additional A$15 million, with commitments reportedly significantly in excess of the maximum sought.
The raising was priced at 19c, a 14% discount to the past 15-day trading average price, and Canaccord Genuity managed the placement.
It last raised $2 million at 7c in mid-2020.
Managing director Ryan Parkin said the company was now funded to complete the class three feasibility study, with the aim of being ready for a final investment decision later this year.
He said the demand showed "the international investment community understands that the inevitable, wide-spread transition to electric mobility will result in critical shortages in lithium-ion battery materials".
European investors were key backers, in line with European Union policies to develop a fully-integrated battery supply chain across the continent, backed with a €750 billion coronavirus recovery fund, which includes low-cost loans for green energy initiatives.
Europe is tipped to become the second largest market for battery-grade lithium after China, and the EU is looking to ban imported batteries not in compliance with stringent sustainability and CO2 profile requirements.
Infinity is looking to help fund San Jose by accessing loans from the EIT InnoEnergy-backed Battchain consortium submission, which has outlined €1.2 billion in funding, with the Australian junior saying it is well-placed to provide battery-grade lithium hydroxide to battery makers serving the Spanish automotive sector.
Infinity is working with InnoEnergy in advancing key tests for development of lithium hydroxide, and is planning to develop a pilot plant.
Infinity owns 75% of San Jose, described as Europe's second-largest hard rock JORC resource, and has an option to move to 100% by paying €10 million at any time prior to FID.
Prefeasibility work completed in 2019 indicated up-front capital of US$309 million would be required for a 30-year development, with modelling calculating San Jose's met present value at $860 million.
Infinity's stock has traded between A3-28c over the past year, with the shares trading between 23-25c in early trade, with the company worth about $73 million at that level.