Silicon‐based suspension electrodes represent one of the most promising candidates as negolyte to replace lithium metal for high energy density semi‐solid flow batteries (SSFBs). Nevertheless, it remains a critical challenge to obtain Si‐based negolyte with highly loaded active material and low viscosity, which are essential for its practical application. Here, the effects of two common non‐ionic surfactants – polyvinylpyrrolidone (PVP) and Triton X‐100 (TX‐100) – on rheological, electrical and electrochemical properties of highly loaded Si (30 vol % Si) negolyte were systemically studied. It was found that the viscosity is effectively decreased by introducing steric and/or depletion interactions when adding a certain amount of non‐ionic surfactant polyvinylpyrrolidone (PVP), while good electrochemical performance of the Si negolyte was maintained. An optimal Si negolyte (adding 0.4 wt % PVP) with a low viscosity of 240 mPa s at a shear rate of 40 s−1 (i. e. about five times lower than the PVP‐free suspension) exhibits a high reversible capacity (ca. 1300 mAh/g) and stable cycling performance (>100 cycles) with a high coulombic efficiency (>98 %). In contrast, TX‐100 can react with lithium salt in the electrolyte and is not suitable to decrease the viscosity of Si negolyte. The highly loaded Si negolyte with low viscosity reported in the present work is promising for practical high energy density lithium‐free SSFBs.

In this work, we have successfully designed ordered luminescent multilayer films based on La-doped nonmagnetic or magnetic inorganic nanostructure with electronic microenvironment (EM). The inorganic nanosheets with opposite charge can assemble EM between the interlayers. At the same time, their elements on nanosheets of layer double hydroxides (LDHs) are facile to be replaced so that we can introduce transition metal or lanthanide elements. Besides, ferromagnetic effect (FE) can be formed in this microenvironment due to introducing transition metal on LDHs nanosheets. As a result, we confirm that EM, FE, and doping La element in the LDHs can affect the vibration of backbone of chromophores and then prolong the luminescent lifetime, which suggests a new pathway for developing the novel light-emitting thin films.

Suspension electrode is the core of flowable electrochemical energy storage systems, which are considered suitable for large-scale energy storage. Nevertheless, obtaining suspension electrodes with both low viscosity and high conductivity is still a big challenge. In present work, spinel LiMn2O4 was chosen as an example to make suspension with low viscosity and high conductivity through microstructure morphology control of solid particles and the contact mode between active materials and conductive additives in suspension electrode. By coating a thin layer of polyaniline on the surface of spherical spinel LiMn2O4, the resulting suspension showed much higher electronic conductivity (about 10 times) and lower viscosity (about 4.5 times) as compared to irregular and bare spinel LiMn2O4-based suspension counterpart. As a result, the Li-ion flow capacitor based on LiMn2O4 and activated carbon suspensions exhibited a record energy density of 27.4 W h L−1 at a power density of 22.5 W L−1 under static condition to date, and can be smoothly work under an intermittent-flow mode. The strategy reported in this work is an effective way for obtaining suspension electrodes with low viscosity and high electronic conductivity simultaneously. It can not only be used in the flow capacitors, but also can be extended to other flowable electrochemical energy storage systems.