Substantial effort has been devoted to both scientific and technological developments of wearable, flexible, semitransparent, and sensing electronics (e.g., organic/perovskite photovoltaics, organic thin‐film transistors, and medical sensors) in the past decade. The key to realizing those functionalities is essentially the fabrication of conductive electrodes with desirable mechanical properties. Conductive polymers (CPs) of poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) have emerged to be the most promising flexible electrode materials over rigid metallic oxides and play a critical role in these unprecedented devices as transparent electrodes, hole transport layers, interconnectors, electroactive layers, or motion‐sensing conductors. Here, the current status of research on PEDOT:PSS is summarized including various approaches to boosting the electrical conductivity and mechanical compliance and stability, directly linked to the underlying mechanism of the performance enhancements. Along with the basic principles, the most cutting edge‐progresses in devices with PEDOT:PSS are highlighted. Meanwhile, the advantages and plausible problems of the CPs and as‐fabricated devices are pointed out. Finally, new perspectives are given for CP modifications and device fabrications. This work stresses the importance of developing CP films and reveals their critical role in the evolution of these next‐generation devices featuring wearable, deformable, printable, ultrathin, and see‐through characteristics.

Lattice oxygen can play an intriguing role in electrochemical processes, not only maintaining structural stability, but also influencing electron and ion transport properties in high-capacity oxide cathode materials for Li-ion batteries. Here, we report the design of a gas–solid interface reaction to achieve delicate control of oxygen activity through uniformly creating oxygen vacancies without affecting structural integrity of Li-rich layered oxides. Theoretical calculations and experimental characterizations demonstrate that oxygen vacancies provide a favourable ionic diffusion environment in the bulk and significantly suppress gas release from the surface. The target material is achievable in delivering a discharge capacity as high as 301 mAh g⁻¹ with initial Coulombic efficiency of 93.2%. After 100 cycles, a reversible capacity of 300 mAh g⁻¹ still remains without any obvious decay in voltage. This study sheds light on the comprehensive design and control of oxygen activity in transition-metal-oxide systems for next-generation Li-ion batteries.

Since the commercialization of lithium‐ion batteries (LIBs) in the early 1990s, tin (Sn), antimony (Sb), and germanium (Ge)‐based anodes have attracted considerable research interest as promising candidates for next‐generation LIBs due to their high theoretical capacities, suitable operating voltages, and natural abundance. Additionally, the awareness of limited global lithium sources promoted the renaissance of sodium‐ion batteries (SIBs) in recent years. Sn, Sb, and Ge can electrochemically alloy with sodium and are regarded as promising anode candidates for high‐performance SIBs. However, these alloying/dealloying anodes suffer severe volume expansion during lithiation or sodiation processes, which is one of the biggest obstacles toward practical applications. In order to solve this problem, several strategies are developed including reducing the absolute size of particles, creating interior void space, and introducing buffer media. After more than two decades' efforts, the electrochemical performance of Sn, Sb, and Ge‐based anodes is significantly improved. Considerable studies about Sn, Sb, and Ge‐based anodes are summarized in a chronicle perspective and the brief development histories of the three anodes are outlined. With this unique review, light will be shed on the future trends of the studies on the Sn, Sb, and Ge‐based anodes for advanced rechargeable batteries.

The cyclability of lithium-ion batteries (LIBs) is often affected by the components of the solid electrolyte interphase (SEI) layer which is generated from electrochemical decomposition of electrolyte. Here, lithium difluorophosphate (LiPO₂F₂) is studied in this work. When 1.6 wt% LiPO₂F₂ additive is incorporated into the reference electrolyte, the capacity retention of graphite/Li half-cell is increased from 82.53% to 98.04% and the capacity retention of LiCoO₂/Li half-cell is increased from 89.60% to 97.53% after 160 cycles. Electrochemical impedance spectroscopy (EIS) indicates that the SEI layer containing LiPO₂F₂ can decrease the surface impedance of cells in the last stage cycle. In situ atomic force microscopy (AFM), DFT calculations and X-ray photoelectron spectroscopy (XPS) results show that LiPO₂F₂ is deposited on the surface of both LiCoO₂ and graphite electrodes, which effectively protects the graphite anode and suppresses the degradation of the cathode during the long-term cycling of LIBs.

Fluorinated electrolytes based on fluoroethylene carbonate (FEC) have been considered as promising alternative electrolytes for high-voltage and high-energy capacity lithium-ion batteries (LIBs). However, the compatibility of the fluorinated electrolytes with graphite negative electrodes is unclear. In this paper, we have systematically investigated, for the first time, the stability of fluorinated electrolytes with graphite negative electrodes, and the result shows that unlike the ethylene carbonate (EC)-based electrolyte, the FEC-based electrolyte (EC was totally replaced by FEC) is incapable of forming a protective and effective solid electrolyte interphase (SEI) that protects the electrolyte from runaway reduction on the graphite surface. The reason is that the lowest unoccupied molecular orbital energy levels are also lowered by the introduction of fluorine into the solvent, and the FEC solvent has poorer resistance against reduction, leading to instability on the graphite negative electrode. To tackle this problem, two lithium salts of lithium bis(oxalato)borate and lithium difluoro(oxalato)borate (LiDFOB) have been investigated as negative-electrode film-forming additives. Incorporation of only 0.5 wt % LiDFOB to a FEC-based electrolyte [1.0 M LiPF₆ in 3:7 (FEC–ethyl methyl carbonate)] results in excellent cycling performance of the graphite negative electrode. This improved property originates from the generation of a thinner and better quality SEI film with little LiF by the sacrificial reduction of the LiDFOB additive on the graphite negative electrode surface. On the other hand, this additive can stabilize the electrolyte by scavenging HF. Meanwhile, the incorporated LiDFOB additive has positive influence on the interphase layer on the positive electrode surface and significantly decreases the amount of HF formation, finally leading to improved cycling stability and rate capability of LiNi_0.5Mn_1.5O₄ electrodes at a high cutoff voltage of 5 V. The data demonstrate that the LiDFOB additive not only exhibits a superior compatibility with graphite but also improves the electrochemical properties of high-voltage spinel LiNi_0.5Mn_1.5O₄ positive electrodes considerably, confirming its potential as a prospective, multifunctional additive for 5 V fluorinated electrolytes in high-energy capacity lithium-ion batteries (LIBs).

Separators with high reliability and security are in urgent demand for the advancement of high performance lithium ion batteries. Here, we present a new and practical porous membrane with three-dimension (3D) heat-resistant skeleton and high curvature pore structure as a promising separator candidate to facilitate advances in battery safety and performances beyond those obtained from the conventional separators. The unique material properties combining with the well-developed structural characteristics enable the 3D porous skeleton to own several favorable properties, including superior thermal stability, good wettability with liquid electrolyte, high ion conductivity and internal short-circuit protection function, etc. which give rise to acceptable battery performances. Considering the simply and cost-effective preparation process, the porous membrane is deemed to be an interesting direction for the future lithium ion battery separator.