considered as a promising alternative to graphite anode, the energy density of Li 4 Ti 5 O 12 is severely limited by its low theoretical specific capacity (175 mAh g -1 ) and high lithiation potential (1.5 V vs Li + / Li) [4][5][6][7] . Low lithiation potential (0.2 V vs Li + /Li) of silicon anode with the highest specific capacity (3579 mAh g -1 ) could inevitably result in serious lithium dendrites in fast charging process. [8][9][10][11] Phosphorus with a high theoretical specific capacity (2596 mAh g -1 ) and suitable lithiation potential (0.7 V vs Li + /Li) is an ideal anode material with high-energy density and fast-charging capability [1][2][3] (Figure 1a). However, the high-rate capability of P anode is hindered by its low electronic (≈10 −12 S m -1 ) and sluggish lithiation reaction kinetics that are two important influencing factors for fast-charging electrode. In addition, the unstable solidelectrolyte interphase (SEI) is due to the side reactions at the interface of electrode and electrolyte as well as the large volume expansion (≈300%) of P upon lithiation, what is worse, the dissolution behavior of intermediates (lithium polyphosphides, Li x Ps) results in low Coulombic efficiency and continual capacity fading, impairing the long-cycling stability. [12,13] To solve these problems, various carbon carriers and conductive polymer coating layers are usually introduced into P anode. [1][2][3][14][15][16][17][18] However, high Li diffusion barriers in carbon-based frameworks (0.34 eV) [19] and the heterogeneous interface, respectively, hinder the superior fastcharging performance of P-based composites. In addition, the problem of uneven local reaction in P particles has not been solved yet.Herein, to enhance the fast-charging performance, we introduced electrochemically active bismuth, a 2D layered material with a layer spacing of 0.396 nm, [20,21] into P/graphite (P/C) composite as a functional filler by the ball-milling method. Bi works as an anode with a similar electrochemical-reaction potential range as P anode, but the starting lithiation/delithiation potential is a little bit higher/lower than the latter, respectively. Besides, Bi anode offers excellent Li-ion diffusion and electron transport capability, combined with the strong interaction at interface of Bi and P, which can promote both Li ion and electron transport at the interface between Bi and P anode. Thus, Bi can work as a small Li reservoir for trapping Li in lithiation process and emitting Li in delithiation process prior to P Phosphorus anodes are a promising for fast-charging high-energy lithium-ion batteries because of their high specific capacity (2596 mAh g -1 ) and suitable lithiation potential (0.7 V vs Li + /Li). To solve the large volumetric change and inherent poor electrical conductivity, various carbon-based materials have been studied for loading P. However, the local aggregation of Li ions and electrons in P particles especially in the fast-charging process induces an uneven lithiation reaction and the great transient stress...

Absolute pKas of selected salts with different counter-anions were measured with high precision in four aprotic ionic liquids (AILs), which enables a detailed examination of solvation effect of ILs on salts. Interestingly, the counter-anions of the ylide precursor salts, protic amine, and phenol salts of this study, though differing dramatically in size and electron dispersion, were found to have no effect on the respective pKas of the substrates. This indicates that the ionic species generated upon acidic dissociation of the salts in weakly polar AILs of low dielectric constant (ε: 10-15) are not ion-paired, or in other words, behave like "free ions" as if in strongly dissociating molecular solvents of high polarity (e.g., DMSO). This suggests that the widely assumed ion-pairing phenomenon, an issue of much debate, is not important in the AILs under our experimental conditions, presenting a typical "ionic-liquid effect" on the solvation of charged species in AILs.

Li‐Ion Batteries In article number 2103888, Jie Sun and co‐workers report the development of a Bi anode that works as a small Li reservoir for trapping/emitting Li in lithiation/delithiation processes prior to that of the P anode. Nezha, a protection deity in Chinese folk religion, defeated the Dragon King who caused the flood. Similarly, Bi promotes fast and uniform lithiation/delithiation reactions and avoids continuous cracking of the Bi‐P/C electrode.

Lithium‐metal batteries (LMBs) using lithium‐metal anodes and high‐voltage cathodes have been deemed as one of the most promising high‐energy‐density battery technology. However, its practical application is largely hindered by the notorious dendrite growth of lithium‐metal anodes, the fast structure degradation of the cathode, and insufficient electrode–electrolyte interphase kinetics. Here, a dual‐anion regulated electrolyte is developed for LMBs using lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and lithium difluoro(bisoxalato)phosphate (LiDFBOP) as anion regulators. The incorporation of TFSI− in the solvation sheath reduces the desolvation energy of Li+, and DFBOP− promotes the formation of highly ion‐conductive and sustainable inorganic‐rich interphases on the electrodes. Significantly enhanced performance is demonstrated on Li||LiNi0.83Co0.11Mn0.06O2 pouch cells, with 84.6% capacity retention after 150 cycles in 6.0 Ah pouch cells and an ultrahigh rate capability up to 5 C in 2.0 Ah pouch cells. Furthermore, a pouch cell with an ultralarge capacity of 39.0 Ah is fabricated and achieves an ultrahigh energy density of 521.3 Wh kg−1. The findings provide a facile electrolyte design strategy for promoting the practical utilization of high‐energy‐density LMBs.

The equilibrium basicities of 21 frequently used amines in two room-temperature ionic liquids (RTILs) were measured precisely. The standard deviation was much superior to that sparsely reported elsewhere. The data comparisons revealed that amines are stronger bases in ionic ligquids than in DMSO and water but weaker base than in acetonitrile (AN). Interestingly, regression analyses demonstrate that the basicity scales obtained in two RTILs correlate well with that in AN but not with those in water and DMSO.