In this work, a Si@C microsphere composite with multiple buffer structures is prepared by hydrothermal treatment to solve the fatal drawbacks of serious pulverization and low electronic conductivity of Si anodes. By virtue of ferric citrate being the carefully chosen coating carbon source, the silicon nanoparticles with a SiO layer are encapsulated by the homogeneous mesoporous carbon layer. The SiO layer with appropriate toughness can primarily suppress the volume expansion of silicon. The plentiful mesopores in the carbon layer and the framework formed by carbon nanotubes with good mechanical strength can effectively buffer and accommodate the volume change of silicon, and greatly improve the infiltration of the electrolyte to the anode. Meanwhile, the mesoporous carbon and carbon nanotube network also enhance the conductivity of the composite. Therefore, the Si@C electrodes exhibit a high initial charge/discharge capacity of 2956/4197 mAh g at a current density of 0.42 A g , excellent rate capability, and outstanding cycle performance up to 800 cycles by virtue of the multiple buffer structures.

A novel silicon–carbon composite with a 3D pore-nest structure denoted as Si@SiOx/CNTs@C was prepared and studied, and the capacity of a Si@SiOx/CNTs@C composite anode can be maintained at above 1740 mA h g−1 at a current density of 0.42 A g−1 after 700 cycles.

In view of the problem of marine plastic pollution and oil resource depletion, an innovative attempt was made to obtain biobased seawater-degradable polyesters by installing lactic acid (LA) into the poly(butylene succinate) (PBS) backbone and synthesizing a series of random copolyesters named poly(butylene succinate-L-lactide)s (PBSLs). Herein, biobased LA units are chosen as readily hydrolyzable points according to our theoretical calculation. The obtained PBSL copolyesters preserve the structure of PBS when LA units are inserted into this main chain mostly with a single unit. While maintaining excellent mechanical and thermal properties, PBSL shows notably improved degradation performance during a 440-day long-term test in natural seawater compared to PBS, demonstrating rapid loss of weight and mechanical properties, as well as a decrease in the molecular weight. A highly sensitive system for end-product CO 2 detection during the seawater degradation process is designed and applied for the first time under conditions close to the natural seawater environment. A record mineralization rate of 16.2% in seawater after 379 days of degradation is achieved for PBSL30, which proved the occurrence of biodegradation in seawater. This result, combined with the analysis of intermediate products, clearly explained the whole degradation mechanism of PBSLs in seawater.