A mixed anion hydroborate/carba-hydroborate as a room temperature Na-ion solid electrolyte

4 V room-temperature all-solid-state sodium battery enabled by a passivating cathode/hydroborate solid electrolyte interface

“…S2a and b (ESI †) confirm phase purity based on reported crystal structures. 36,53 Primary Na 3 (VOPO 4 ) 2 F particles exhibit plate-and rod-like morphologies with 2-10 mm length and preferred orientation in the [0 0 2] direction (see Fig. S2b and d, ESI †).…”

“…S4 and S5, ESI †). 36,45 Next, we analyze the electrochemical oxidative stability of the mixed-anion Na 4 (CB 11 H 12 ) 2 (B 12 H 12 ) by cyclic voltammetry shown in Fig. 2a, using a SE/carbon composite with a 75 : 25 weight ratio as a working electrode and a platinum disk as a current collector, separated from a sodium metal electrode by a SE without carbon, as previously reported by some of us.…”

Ethanol- and Methanol-Coordinated and Solvent-Free Dodecahydro closo-Dodecaborates of 3d Transition Metals and of Magnesium

“…Our interest in TM closo-borates started with studies of closo-borates as solid electrolytes [13][14][15][16][17][18][19]. The TM closo-borates were considered as materials for electrodes in Li-and Na-ion solid-state batteries thus providing chemical compatibility of electrode/electrolyteinterface.…”

Beyond Typical Electrolytes for Energy Dense Batteries

“…A recent report examined the Li salt conductivity in mixed 7:3 molar CB 9 H 10 − :CB 11 H 12 − prepared by ball milling also demonstrated very high conductivity of 6.7 × 10 −3 S/cm at room temperature without thermal activation ( Figure 4) [70]. Other studies examined mixing Na carborate CB 11 H 12 − with hydroborate B 12 H 12 − salts and also showed high conductivities (2 × 10 −3 S/cm at room temperature), albeit lower than those observed for closo-carborates [71]. Studies in carborate-type derivatives based on several nido-carborates demonstrated inferior conductivities to those reported in closo-carborates [72] (note: surprisingly a high value in the order of 10 −3 S/cm at 300 K was reported for what was described as α-NaCB 11 H 14 , it remains unclear why the conductivity was much higher than that in typical NaCB 11 H 14 , 10 −6 S/cm at 300 K).…”