TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The alkali metal alkoxy orthoborate salt is lithium tetramethanolatoborate. The silylating agent is hexamethyldisiloxane and the metal alkoxy orthoborate salt is lithium tetramethanolatoborate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The anion stabilizing monomer comprises monomer selected from monomers of formulae (III)-(VIII).R'1, R'2, R'4, R'5, R'6 and R'7=T1;R'8, and R'11=H or 1-4C alkyl (optionally substituted with H, halo, or 1-4C alkoxy);m1=1-2;m2, m4, m5, and m6=1-4;m7=1-3.    TECHNOLOGY FOCUS - POLYMERS - Preferred Compounds: The sp3 boron-based single-ion conducting polymer electrolyte is selected from 8 compounds, as given in the specification, e.g. compound of formula (I) and (II). The polymer has weight average molecular weight of approximately 8000-40000.M'=H or alkali metal (such as lithium, sodium or potassium);a=optional bond;R1 and R2=T1;T1=1-4C alkyl, 1-4C alkoxy, 1-4C alkyl amino, 1-4C dialkyl amino, 1-4C acyl, or (1-4C)NR3C(O) (all optionally substituted by H, halo, 1-4C alkyl, 1-4C alkoxy, 1-4C halo alkyl, 1-4C haloalkoxy, 1-4C alkyl amino, 1-4C dialkyl amino, or 1-4C acyl), H, or halo;orR1+R2=6-10C aryl ring (optionally mono- to tetra-substituted with R4);R3 and R5=H or 1-4C alkyl (optionally substituted with H, halo, or 1-4C alkoxy);R4=T1;n=1-100.Preparation (Claimed): Preparation of the sp3 boron-based single-ion conducting polymer electrolyte involves:(1) process (A): heating a mixture of a carboxylic acid and a silylating agent to form a silylated carboxylic acid intermediate; and heating a mixture of the silylated carboxylic acid intermediate with a metal alkoxy orthoborate salt to form a sp3 boron-based single-ion conducting polymer electrolyte; and(2) process (B): heating a mixture of an alcohol and an alkoxy orthoborate salt to form a sp3 boron-based single-ion conducting polymer electrolyte. EXAMPLE - Pyromellitic acid and anhydrous 1,2-dichIoroethane (DCE) were placed in a flask under an atmosphere of argon. Hexamethyldisilane (HMDS) was then added and the resulting mixture was heated to 100 degrees C and stirred until all of the acid was consumed. After work up, silylated intermediate of formula (ia) was obtained. The silylated intermediate (ia), lithium tetramethanolatoborate and a small amount of anhydrous N,N-dimethylformamide (DMF) were placed in a flask and stirred under an argon atmosphere for 3 days. After work up poly (pyromellitic acid borate) (PPAB) of formula (I') (having number average molecular weight (Mn) of 7360 g/mol, weight average molecular weight (Mw)/Mn of 1.21, and Mw of 0.89x 104) was obtained.