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The demand for lithium compensation materials is becoming urgent as energy density requirements increase. As next-generation anodes, mixed silicon and carbon (Si−C) materials are limited by low efficiency in the first cycle owing to the formation of a solid electrolyte interphase film. However, most compensation materials are water-and oxygen-sensitive and exhibit low electrochemical activity and decomposition efficiency. In this study, water-and oxygen-stable lithium oxalate (Li 2 C 2 O 4 ) was developed to enhance the capacity and cycle-life of the lithium-ion battery. Various metal oxides were screened to improve the electrochemical activity of Li 2 C 2 O 4 . Co 3 O 4 exhibited the strongest catalytic performance, and the catalytic mechanism of Co 3 O 4 on Li 2 C 2 O 4 was studied by density functional theory. Ultrasonic atomization drying was used to combine Co 3 O 4 quantum dots (Co 3 O 4 -QDs) with Li 2 C 2 O 4 for improved efficiency. The electrochemical activity of the modified Li 2 C 2 O 4 improved, and the decomposition voltage decreased from 4.65 to 4.0 V. The modified Li 2 C 2 O 4 exhibits catalytic activity, and it can be used in LiFePO 4 , which has weak catalytic activity; the decomposition efficiency in the LiFePO 4 system increased from 34.16 to 99.10%. In the Si−C//LiFePO 4 full battery system, the first cycle discharge capacity increased from 80 to 160 mA h g −1 ; the lost capacity of the first cycle was fully compensated for. Additionally, the CO 2 produced by Li 2 C 2 O 4 decomposition could inhibit the decomposition of the electrolyte, further improving the cycle performance of the battery.

Visible-infrared compatible camouflage is significant to enhance the equipment survivability through counteracting the modern detecting and surveillance systems. However, there are still great challenges in simultaneously achieving multispectral camouflage with high transmittance in visible, low emissivity in the atmospheric windows and high emissivity in the non-atmospheric window, which can be attributed to the mutual influence and restriction within these characteristics. Here, we proposed an optically transparent infrared selective emitter (OTISE) composed of three Ag-ZnO-Ag disk sub-cells with anti-reflection layers, which can synchronously improve the visible transmittance and widen absorption bandwidth in the non-atmospheric window by enhancing and merging resonance response of multi-resonators. Test results reveal that low emissivity in infrared atmospheric windows, high emissivity in the 5-8 µm non-atmospheric window and high optical transparency have been obtained. In addition, the radiative flux of OTISE in 3-5 µm and 8-14 µm are respectively 34.2% and 9.3% of that of blackbody and the energy dissipation of OTISE is 117% of that of chromium film. Meanwhile, it keeps good optical transparency due to the ultrathin Ag film. This work provides a novel strategy to design the optically transparent selective emissive materials, implying a promising application potential in visible and infrared camouflage technology.