** Shares of Novonix NVX.AX soar as much as 18.1% to A$0.850, set for best day since mid-March - if current gains hold
** Battery tech firm hits highest since late Oct
** Says it has signed a binding offtake agreement with Stellantis STLAM.MI
** Says agreement to supply minimum of 86,250 tonnes, up to a target volume of 115,000 tonnes of high-performance synthetic graphite material
** Adds material to be supplied from its Riverside facility in Chattanooga, Tennessee, to Stellantis' cell manufacturing partners in North America from 2026 until 2031
** Including day's moves, stock has risen ~12.2% this year
(Reporting by Archishma Iyer)
((Archishma.Iyer@thomsonreuters.com;))