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The binary transition metal-based nitrides are promising for overall water splitting. The morphology and heterojunction engineering are important to realize the effective catalysis, but simultaneous engineering of them remains a...

Transition-metal sulfides are key cathode materials for thermal batteries used in military applications. However, it is still a big challenge to prepare sulfides with good electronic conductivity and thermal stability. Herein, we rapidly synthesized a Co-doped NiS2 micro/nanostructure using a hydrothermal method. We found that the specific capacity of the Ni1–x Co x S2 micro/nanostructure increases with the amount of Co doping. Under a current density of 100 mA cm–2, the specific capacity of Ni0.5Co0.5S2 was about 1565.2 As g–1 (434.8 mAh g–1) with a cutoff voltage of 1.5 V. Owing to the small polarization impedance (5 mΩ), the pulse voltage reaches about 1.74 V under a pulse current of 2.5 A cm–2, 30 ms. Additionally, the discharge mechanism was proposed by analyzing the discharge product according to the anionic redox chemistry. Furthermore, a 3.9 kg full thermal battery is assembled based on the synthesized Ni0.5Co0.5S2 cathode materials. Notably, the full thermal battery discharges at a current density of 100 mA cm–2, with an operating time of about 4000 s, enabling a high specific energy density of around 142.5 Wh kg–1. In summary, this work presents an effective cathode material for thermal battery with high specific energy and long operating life.

Covalent organic frameworks are promising electrode materials for energy storage due to their uniform active sites, abundant pores, and high stability. However, the reported COF electrodes often display low discharge...

Iron trifluoride (FeF 3 ) might be a suitable high-voltage cathode material for high-power thermal batteries due to its high voltage plateau, low cost and low toxicity. In this study, anhydrous FeF 3 was synthesized and its applicability as a cathode material for thermal batteries was investigated. Its structure, thermal stability and electrochemical properties were also studied. The synthesized anhydrous FeF 3 had a hierarchical structure and a decomposition threshold temperature of 800°C. At a current density of 100 mA cm −2 , the Li-B/FeF 3 single cell exhibited an initial discharge voltage of 3.20 V and a specific capacity of 81.9 mA h g −1 with a cutoff voltage of 2.0 V. Moreover, multi-walled carbon nanotubes (MWCNTs) were used as the conductive agents, leading to an decreasing of the total polarization from 45 m to 10 m . In specific, the Li-B/ FeF 3 -MWCNTs single cell exhibited an initial discharge voltage of 3.27 V and a specific capacity of 160.7 mAh•g −1 . This work provides a beginning for further applying FeF 3 as a high-voltage cathode material for high-power thermal batteries.

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Rigid body orientation determined by IMU (Inertial Measurement Unit) is widely applied in robotics, navigation, rehabilitation, and human-computer interaction. In this paper, aiming at dynamically fusing quaternions computed from angular rate integration and FQA algorithm, a quaternion-based complementary filter algorithm is proposed to support a computationally efficient, wearable motion-tracking system. Firstly, a gradient descent method is used to determine a function from several sample points. Secondly, this function is used to dynamically estimate the fusion coefficient based on the deviation between measured magnetic field, gravity vectors and their references in Earth-fixed frame. Thirdly, a test machine is designed to evaluate the performance of designed filter. Experimental results validate the filter design and show its potential of real-time human motion tracking.

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