Sodium‐based dual ion full batteries (NDIBs) are reported with soft carbon as anode and graphite as cathode for the first time. The NDIBs operate at high discharge voltage plateau of 3.58 V, with superior discharge capacity of 103 mA h g−1, excellent rate performance, and long‐term cycling stability over 800 cycles with capacity retention of 81.8%. The mechanism of Na+ and PF6− insertion/desertion during the charging/discharging processes is proposed and discussed in detail, with the support of various spectroscopies.

We report an in situ alloying strategy for obtaining homogeneous (Bi,Sb) alloy nanoparticles from (Bi,Sb)2S3 nanotubes for the exceptional anode of potassium ion batteries (KIBs). The operando X-ray diffraction results, along with transmission electron microscopy and energy-dispersive X-ray spectroscopy mappings, successfully reveal the phase evolution of this material, which is (Bi,Sb)2S3 → (Bi,Sb) → K­(Bi,Sb) → K3(Bi,Sb) during the initial discharge and K3(Bi,Sb) → K­(Bi,Sb) → (Bi,Sb) in the charging process. The in situ alloying strategy produces a synergistic effect and brings an outstanding electrochemical performance. It achieves ultrahigh discharge capacities of 611 mAh g–1 at 100 mA g–1 (0.135C) and 300 mAh g–1 at 1000 mA g–1 (1.35C) and retains a capacity as high as 353 mAh g–1 after 1000 cycles at 500 mA g–1 (0.675C) with a Coulombic efficiency close to 100%. In addition, the KIBs full cell, which is composed of this anode and a perylenetetracarboxylic dianhydride cathode, reaches an initial discharge capacity as high as 276 mAh g–1 at 500 mA g–1 and maintains 207 mAh g–1 after 100 cycles.

Potassium ion-batteries (PIBs) have attracted tremendous attention recently due to the abundance of potassium resources and the low standard electrode potential of potassium. Particularly, the solid-electrolyte interphase (SEI) in the anode of PIBs plays a vital role in battery security and battery cycling performance due to the highly reactive potassium. However, the SEI in the anode for PIBs with traditional electrolytes is mainly composed of organic compositions, which are highly reactive with air and water, resulting in inferior cycle performance and safety hazards. Herein, a highly stable and effective inorganic SEI layer in the anode is formed with optimized electrolyte. As expected, the PIBs exhibit an ultralong cycle performance over 14 000 cycles at 2000 mA g and an ultrahigh average coulombic efficiency over 99.9%.

A potassium ion battery has potential applications for large scale electric energy storage systems due to the abundance and low cost of potassium resources. Dual graphite batteries, with graphite as both anode and cathode, eliminate the use of transition metal compounds and greatly lower the overall cost. Herein, combining the merits of the potassium ion battery and dual graphite battery, a potassium-based dual ion battery with dual-graphite electrode is developed. It delivers a reversible capacity of 62 mA h g and medium discharge voltage of ≈3.96 V. The intercalation/deintercalation mechanism of K and PF into/from graphite is proposed and discussed in detail, with various characterizations to support.

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