Aqueous ammonium‐ion storage has been considered a promising energy storage competitor to meet the requirements of safety, affordability, and sustainability. However, ammonium‐ion storage is still in its infancy in the absence of reliable electrode materials. Here, defective VO2 (d‐VO) is employed as an anode material for ammonium‐ion batteries with a moderate transport pathway and high reversible capacity of ≈200 mAh g−1. Notably, an anisotropic or anisotropic behavior of structural change of d‐VO between c‐axis and ab planes depends on the state of charge (SOC). Compared with potassium‐ion storage, ammonium‐ion storage delivers a higher diffusion coefficient and better electrochemical performance. A full cell is further fabricated by d‐VO anode and MnO2 cathode, which delivers a high energy density of 96 Wh kg−1 (based on the mass of VO2), and a peak energy density of 3254 W kg−1. In addition, capacity retention of 70% can be obtained after 10 000 cycles at a current density of 1 A g−1. What's more, the resultant quasi‐solid‐state MnO2//d‐VO full cell based on hydrogel electrolyte also delivers high safety and decent electrochemical performance. This work will broaden the potential applications of the ammonium‐ion battery for sustainable energy storage.

No abstract

No abstract

Aqueous ammonium-ion (NH 4 + ) batteries are becoming the competitive energy storage candidate on account of their safety, affordability, sustainability, and intrinsically peculiar properties. Herein, an aqueous NH 4 + -ion pouch cell is investigated based on a tunneled manganese dioxide (α-MnO 2 ) cathode and a 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) anode. The MnO 2 electrode possesses a high specific capacity of ∼190 mA h g −1 at 0.1 A g −1 and displays excellent long cycling performance after 50,000 cycles in 1 M (NH 4 ) 2 SO 4 , which outperforms the most reported ammonium-ion host materials. Besides, a solid-solution behavior is revealed about the migration of NH 4 + in the tunnel-like α-MnO 2 . The battery displays a splendid rate capacity of 83.2 mA h g −1 even at 10 A g −1 . It also exhibits a high energy density of ∼78 W h kg −1 as well as a high power density of ∼8212 W kg −1 (based on the mass of MnO 2 ). What is more, the flexible MnO 2 //PTCDA pouch cell based on the hydrogel electrolyte shows excellent flexibility and good electrochemical properties. The topochemistry results of MnO 2 //PTCDA point to the potential practicability of ammonium-ion energy storage.

A multifunctional platform (PVA@rGO-Ag/5-Fu) integrated with photothermal, antibacterial and drug delivery abilities is developed. The experiments proved that PVA@rGO-Ag/5-Fu has potential as an efficacious anti-scarring agent for filtering surgery.

No abstract

No abstract

Deep learning is becoming increasingly ubiquitous in medical research and applications while involving sensitive information and even critical diagnosis decisions. Researchers observe a significant performance disparity among subgroups with different demographic attributes, which is called model unfairness, and put lots of effort into carefully designing elegant architectures to address unfairness, which poses heavy training burden, brings poor generalization, and reveals the trade-off between model performance and fairness. To tackle these issues, we propose FairAdaBN by making batch normalization adaptive to sensitive attribute. This simple but effective design can be adopted to several classification backbones that are originally unaware of fairness. Additionally, we derive a novel loss function that restrains statistical parity between subgroups on mini-batches, encouraging the model to converge with considerable fairness. In order to evaluate the trade-off between model performance and fairness, we propose a new metric, named Fairness-Accuracy Trade-off Efficiency (FATE), to compute normalized fairness improvement over accuracy drop. Experiments on two dermatological datasets show that our proposed method outperforms other methods on fairness criteria and FATE.