The　exploitation　of　high　performance　redox-active　substances　is　critically　important　for　the　development　of　non-aqueous　redox　flow　batteries.　Herein,　three　tetrathiofulvalene　(TTF)　derivatives　with　different　substitution　groups,　namely　TTF　diethyl　ester　(TTFDE),　TTF　tetramethyl　ester　(TTFTM),　and　TTF　tetraethyl　ester　(TTFTE),　are　prepared　and　their　energy　storage　properties　are　evaluated.　It　has　been　found　that　the　redox　potential　and　solubility　of　these　TTF　derivatives　in　conventional　carbonate　electrolytes　increases　with　the　number　of　ester　groups.　The　battery　with　a　catholyte　of　0.2　mol　L−1　of　TTFTE　delivers　a　specific　capacity　of　more　than　10　Ah　L−1　at　the　current　density　of　0.5　C　with　two　discharge　voltage　platforms　locating　at　as　high　as　3.85　and　3.60　V　vs.　Li/Li+.　Its　capacity　retention　can　be　improved　from　2.34　Ah　L−1　to　3.60　Ah　L−1　after　100　cycles　by　the　use　of　an　anion　exchange　membrane　to　block　the　crossover　of　TTF　species.　The　excellent　cycling　stability　of　the　TIF　esters　is　supported　by　their　well-delocalized　electrons,　as　revealed　by　the　density　function　theory　calculations.　Therefore,　the　introduction　of　more　and　larger　electron-withdrawing　groups　is　a　promising　strategy　to　simultaneously　increase　the　redox-potential　and　solubility　of　redox-active　materials　for　non-aqueous　redox　flow　batteries.　©　2022　Institute　of　Process　Engineering,　Chinese　Academy　of　Sciences