Enabling steady graphite anode cycling with high voltage, additive-free, sulfolane-based electrolyte: Role of the binder

We demonstrate here the possibility of operating both high voltage spinel and high mass loading graphite electrodes in a 1M LiPF₆ in SL/DMC (1/1, wt/wt) electrolyte without the use of additive. A crucial point for practical graphite electrode operation is the use of the cheaper and environmentally friendly carboxymethyl cellulose (CMC)/styrene-butadiene rubber (SBR) combination instead of the PVDF-based electrodes used in most laboratory studies. With this type of anode we also show the operation of a full Li-ion cell operating at 4.5 V without any additive and show that most of the Li⁺ transport limitation observed in half-cells are in fact due to the Li metal counter electrode. The anode binder influence is to be considered for the development of high voltage electrolytes lacking good intrinsic SEI building properties, as the anode binder does not affect cathode performance, contrary to most additives. It opens the route for further improvement by use of SEI forming additives (molecular and salts), keeping in mind the requirement for the cathode.