▎ 摘　　要

NOVELTY - A substituted lactone (I) is new. USE - Compound (I) is used for producing polymer used as binder or coating for particles of electrochemically-active material in composition for manufacturing electrolyte, battery separator and electrode material of electrochemical cell for electrochemical accumulator and electrochromic device. The electrochemical accumulator is chosen from lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, and aluminum batteries, preferably lithium battery, sodium battery, potassium battery or magnesium battery, and their ionic versions (all claimed). Uses include but are not limited to mobile phone, camera, tablet, laptop computer, electric or hybrid vehicle, and energy storage device. ADVANTAGE - Compound (I) has improved performance as electrolyte. DETAILED DESCRIPTION - A substituted lactone of formula (I) is new. R -R =H, F, Cl, Rn'O-, Rn'OC(O)-, Rn'C(O)O-, or Rn'C(O)-, 1-12C alkyl or 3-8C cycloalkyl optionally substituted by cyano, fluoro, hydroxy, 1-12C alkyl, 3-8C cycloalkyl, 3-8C heterocycloalkyl, 5-6C heteroaryl, Rn'O-, Rn'OC(O)-, Rn'C(O)O-, or Rn'C(O)-, where at least one of R -R is 1-6C alkyl, 1-3C alkyl, 5-7C cycloalkyl substituted by Rn''O-, Rn''OC(O)-, Rn''C(O)O-, or Rn''C(O)-; Rn'=1-12C alkyl, hydroxy-1-12C alkyl, cyano-1-20C alkyl, 1-12C alkoxy-1-12C alkyl, or oligomeric or polymeric chain; or two adjacent R , R , R or R =ring; m+n=2-9;and Rn''=oligomeric or polymeric chain. INDEPENDENT CLAIMS are included for the following: a polymer, which comprises a lactone-based repeating unit of formula (II); a composition, which comprises the polymer and at least one ionic salt; an electrolyte, which comprises the polymer or the composition; an electrode material, which comprises the polymer or composition, and at least one electrochemically-active material; an electrochemical cell, which comprises an anode, a cathode, an electrolyte, and optionally a separator, where at least one comprises the polymer or composition, and at least one of the anode and cathode comprises the electrode material; an electrochemical accumulator, which comprises the electrochemical cell; and preparation of compound (I).