Developing supercapacitors (SCs) with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes. Although the design of water in salt (WIS) electrolytes has pushed the development of aqueous electrolytes to a new height, the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce. Herein, in order to enrich the type of aqueous electrolyte with high operative voltage, tetramethylammonium trifluoromethanesulfonate (TMAOTf) based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile (ACN) co-solvent and LiTFSI co-solute. In view of the coordination effect of ACN and Li⁺ on free water in TMAOTf based WIS electrolyte, the TMA⁺-Li⁺-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V. Further coupled with the commercial YP-50F electrodes, TMA⁺-Li⁺-AWIS based SCs exhibited wide operative voltage window (2.5 V), long cycling life (45,000 cycles) and good low-temperature performance (99.99 % capacitance retention after 2000 cycles at -20 ^oC). The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.

Nanopipette based scanning probe technique is a versatile tool in non-contact imaging in biology. In addition to the topographic imaging, its capability of localized delivery of bio-active molecules is emerging. In this mini review, we introduce the applications of nanopipette in single-cell researches with a focus on localized delivery. The working principles of three delivery modes including resistive pulse, pressure-driven flow, and electroosmotic flow-driven delivery are summarized and compared. Their applications in single-cell researches are reviewed. The current technical challenges in scanning ion conductance microscopy-based delivery, and their growing influence in medicine and pharmacologic researches are also discussed.

Single-entity collisional electrochemistry (SECE) is a branch of single-entity electrochemistry. It can directly characterize entities/particles with single particle resolution through random collisions between particles and electrodes in a solution, and obtain rich physicochemical information, thus becoming one of the frontiers of electroanalytical chemistry in the past two decades. Interestingly, the (micro/nanoscale) sensing electrodes have evolved from a polarizable liquid/liquid (mercury/liquid) interface to a solid/liquid interface and then to a liquid/liquid interface (i.e., an interface between two immiscible electrolyte solutions, ITIES), as if they have completed a cycle (but in fact they have not). ITIES has become the latest sensing electrode in the booming SECE due to its polarizability (up to 1.1 V at the water/α,α,α-trifluorotoluene interface) and high reproducibility. The four measurement modes (direct electrolysis, mediated electrolysis, current blockade, and charge displacement) developed in the realm of SECE at solid/liquid interfaces have also been fully realized at the miniature ITIES. This article will discuss these four modes at the ITIES from the perspectives of basic concepts, operating mechanisms, and latest developments (e.g., discovery of ionosomes, blockade effect of Faradaic ion transfer, etc.), and look forward to the future development and direction of this emerging field.