Latest ArticlesDue to the serious imbalance between demand and supply of lithium, lithium extraction from brine has become a research hotspot. With the demand for power lithium-ion batteries (LIBs) increased rapidly, a large number of spent LiFePO4 power batteries have been scrapped and entered the recycling stage. Herein, a novel and efficient strategy is proposed to extract lithium from brine by directly reusing spent LiFePO4 powder without any treatment. Various electrochemical test results show that spent LiFePO4 electrode has appropriate lithium capacity (14.62 mgLi/gLiFePO4), excellent separation performance (αLi-Na = 210.5) and low energy consumption (0.768 Wh/gLi) in electrochemical lithium extraction from simulated brine. This work not only provides a novel idea for lithium extraction from brine, but also develops an effective strategy for recycling spent LIBs. The concept of from waste to wealth is of great significance to the development of recycling the spent batteries.
Increasing the charging cut-off potential of lithium cobalt oxide (LiCoO2, LCO) can effectively improve the energy density of the lithium-ion batteries, which are the mainstream energy storage devices used in 3C electronic products. However, the continuous decomposition of the electrolyte and dissolution of Co from the electrode will occur at high-potential operation, which deteriorate the performances of LCO. Here, a cathode-electrolyte interface (CEI) layer containing MgF2 is constructed to enhance the electrochemical stability of LCO at 4.6 V (vs. Li+/Li). The Mg2+ added to the cathode gradually releases into the electrolyte during cycling, which forms a stable MgF2-rich protective layer. In addition, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether (TTE) is added to the electrolyte acting as a F source to increase the content of MgF2 in the CEI layer. The MgF2-rich CEI layer effectively suppresses the decomposition of electrolyte components and the dissolution of Co of LCO, which makes the Li||LiCoO2 (Li||LCO) cell cycled stably at 3~4.6 V (vs. Li+/Li) in 200 cycles with a retention of 83.9%.
Developing efficient and stable electrocatalyst to hydrogen evolution reaction adaptable for electrolytes with different pH is a big challenge. In this work, a hierarchically structured ternary nanohybrid composed of flower-like Ru nanoparticles, rigid macrocyclic cucurbit[6]uril (CB[6]) and carboxylated multi-walled carbon nanotubes (MWCNTs) was successfully prepared by chemical wet method. Benefited by the structural merits of flower-like Ru nanoparticles exposed abundant active sites supported by the MWCNTs holding superior mass transport and electrons transfer ability as well as the existence of CB[6], the obtained catalyst exhibited outstanding HER activities with overpotentials of 27, 37 and 70 mV at −10 mA/cm2 in alkaline, acidic, and neutral electrolytes, respectively. Under the same electrocatalytic operation conditions, the HER performance is comparable or superior to commercial Pt/C catalyst (47, 27 and 49 mV). Besides, chronopotentiometric and accelerated stability test also revealed its extraordinary stability, which could be further employed for electrocatalytic procedure in a broad pH range.
The Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) layered cathodes endow Li-ion batteries (LIBs) with high energy density. However, they usually suffer from limited ion-diffusion and structural instability during cycling. Although doping strategy can effectively alleviate these issues, the coupling effects of multi-element doping and the corresponding performance enhancement mechanism have been yet unclear. Here, we report a Zr/Ti dual-doped NCM811 cathode material (ZT-NCM811), in which Zr-ion is doped into both transition metal (TM) layers and lithium layers and Ti-ion is only distributed in TM layers. The dual-doping can effectively enhance crystal structure stability via inhibiting the lattice collapse along c-axis and decreasing the Li/Ni disorder. Meantime, the lattice oxygen escape is also greatly reduced due to the presence of stronger Zr-O and Ti-O bonds, further mitigating the crystal surface parasitic reactions with electrolyte. The resultant ZT-NCM811 exhibits high specific capacity of 124 mAh/g at even 10 C, much higher than undoped and single-doped NCM811, and a retention of 98.8% at 1 C after 100 cycles. The assembled ZT-NCM811/graphite full cell also delivers superior battery performances and durability.
Carbon materials derived from biomass waste are considered as potential electrocatalysts for applications in zinc-air batteries (ZABs) due to their low cost and good catalytic activity. Here, we reported the preparation of gel-based catalysts through utilizing hydrolyzed waste leather powder cross-linked with metallic salt solutions. After calcination, iron-nickel alloy anchored in nitrogen-doped porous carbon catalysts (FeNi@NDC) was achieved. Compared with commercial Pt/C catalyst, FeNi@NDC-800 exhibited lower E1/2 (0.77 V) and better durability. More importantly, the resulting FeNi@NDC-800-based alkaline ZABs achieved power density of 93.01 mW/cm2 and open circuit voltage of 1.45 V, which the FeNi@NDC-800-based neutral ZAB displayed a charge/discharge cycle stability of 275 h. This work opens up the possibility of rational design and preparation of low-cost and high-performance electrocatalysts from recyclable leather waste.
The electrochemical CO2 reduction reaction (CO2ER) is an emerging process that involves utilizing CO2 to produce valuable chemicals and fuels by consuming excess electricity from renewable sources. Recently, Cu and Cu-based nanoparticles, as earth-abundant and economical metal sources, have been attracting significant interest. The chemical and physical properties of Cu-based nanoparticles are modified by different strategies, and CO2 can be converted into multicarbon products. Among various Cu-based nanoparticles, Cu-based metal-organic frameworks (MOFs) are gaining increasing interest in the field of catalysis because of their textural, topological, and electrocatalytic properties. In this minireview, we summarized and highlighted the main achievements in the research on Cu-based MOFs and their advantages in the CO2ER as electrocatalysts, supports, or precursors.
Lithium-rich manganese-based material shows great potential as the high specific cathode materials due to its low cost, environmental friendliness, high operating voltage and simple preparation process. However, the poor capacity retention and cycling performance caused by its unstable structure during cycling restrict the commercialization. In this work, Li1.2Ni0.16Mn0.56Co0.08O2 was synthesized utilizing a Co-precipitation method and different amount of La(PO3)3 (La(PO3)3 = 2 wt%, 4 wt% and 6 wt%) was selected as the coating layer to resolve the above issues. During the calcination process, La(PO3)3 reacts with impurities such as LiOH and Li2CO3 on the lithium-rich surface to reduce the residual lithium on the surface, thus improving the interfacial stability, slowing down the corrosion of the electrolyte, and finally enhancing its electrochemical performance. The cathode materials coated with 4% of La(PO3)3 showed the best electrochemical performance in terms of capacity retention and cycling performance compared to the pristine NCM. The high initial discharge capacity of 214.21 mAh/g and capacity retention of 94.2% after 100 cycles at 0.1 C can be obtained. This work provides an effective strategy to protect the cathode from corrosion and will promote its further practical applications in high specific Li-ion batteries.
Local delivery of nanomedicines holds therapeutic promise for colorectal cancer (CRC). However, it presents tremendous challenges due to the existence of multiple physiological barriers, especially intracellular obstacles, including intracellular trafficking, subcellular accumulation, and drug release. Herein, we report a multifunctional nanoparticle (CMSNR) by wrapping the mesoporous silica nanorod with cell membrane derived from CRC cells for improved chemotherapy. Compared with their naked counterparts, the cell membrane endowed CMSNR with homotypic targeting and improved cellular uptake capacities. Due to the rod-like shape, CMSNR achieved superior colorectal mucus permeability, enhanced tumor accumulation, and boosted cellular uptake than their spherical counterparts. Moreover, the internalized CMSNR underwent robust intracellular trafficking and gained augmented motility toward the nucleus, leading to efficient perinuclear accumulation and a subsequent 5.6-fold higher nuclear accumulation of loaded drug than that of nanospheres. In the orthotopic colorectal tumor-bearing nude mice, rectally administrated mefuparib hydrochloride (MPH)-loaded CMSNR traversed the colorectal mucus, penetrated the tumor tissue, and successfully aggregated in the perinuclear region of cancer cells, thus exhibiting significantly improved antitumor outcomes. Our findings highlight the shape-based design of cell membrane-coated nanoparticles that can address sequential drug delivery barriers has a promising future in cancer nanomedicine.
As nanocarriers, nanomicelles play vital roles in the toolbox of drug delivery. The stability of nanomicelles affects the nanomedicines’ bioactivity. Therefore, it is important to understand the stability of nanomicelles for further improvements. Here, we report a strategy to construct new nanomicelles (NM) by introducing aggregation-induced emission (AIE) functional group tetraphenylethylene (TPE) in the component polymer vitamin E (d-α-tocopheryl polyethylene glycol 1000 succinate) (TPGS). The stability of doxorubicin (DOX) loaded nanomicelles DOX@NM in different conditions was studied by fluorescence analysis. The fluorescence changes of DOX@NM are ‘seesaw-like’ when they transform between assembled and disassembled forms. In the assembled form, TPE gives emission from AIE effect, while in the disassembled form, the fluorescence of DOX is observed due to the disappearance of ACQ effect.
By introducing a naphthothiadiazole (NT) unit as the main building block, a non-doped and red emissive conjugated polymer poly(9,9-dihexylfluorene-alt-naphthothiadiazole) (PFNT) is readily obtained through a two-step synthesis. Since the NT unit has a large twist angle with its neighboring segment, the aggregation-induced quenching (AIQ) effect of PFNT can be effectively suppressed in the condensed state. As a result, the corresponding PFNT polymer dot (Pdot) exhibits a high fluorescence quantum yield of 53.2% with peak emission at 616 nm, which is one of the most efficient red Pdots known. PFNT Pdot shows good biocompatibility and can be employed for living cell fluorescent imaging with high brightness. It also can be used for specific subcellular organelle imaging through immunofluorescence labeling. Furthermore, the PFNT Pdot demonstrates much better photostability for long-time cell fluorescence imaging than commercial red dyes. The high performances of PFNT Pdot make it a promising fluorescent probe for practical bioapplications.