Improved performance of lithium ion batteries by employment of electrolyte containing nanodiamonds and water

Realized Record Capacity and Rate Performance of Dual-Carbon Batteries Constructed by Introducing Superhard Nanodiamonds

“…The increasing capacity is thus mainly attributed to the anode consisting of DCG and embedded NDs, having additional active sites, enlarged interplanar spacing, and enhanced ion absorption on NDs during the cycling processes. In the in situ XRD pattern of DCG (Figure e), the peak assigned to the graphite (002) plane at ∼25.8° redshifts to ∼23.4° corresponding to the formation of graphite interlayer compounds (GICs) with great lattice expansion, and the adsorption of Li-ions on the surface of DCG and NDs does not cause lattice change. , All the peaks shifted back to the initial position during the charging process, demonstrating the reversibility of Li-ions’ intercalation/deintercalation or adsorption/desorption.…”

“…In the in situ XRD pattern of DCG (Figure 2e), the peak assigned to the graphite (002) plane at ∼25.8°redshifts to ∼23.4°c orresponding to the formation of graphite interlayer compounds (GICs) with great lattice expansion, 37 and the adsorption of Li-ions on the surface of DCG and NDs does not cause lattice change. 22,27 All the peaks shifted back to the initial position during the charging process, demonstrating the For realizing high performances of DIBs, the electrochemical properties of the cathode are of the utmost importance factor, as a suitable cathode material plays a critical role in achieving efficient reversible storage and conversion of large-sized PF 6 − anions. 3 In the CV test of Li//DCG half-cell (Li as the counter electrode, DCG as the cathode) with normal electrolyte (3 M LiPF 6 dissolved in a solvent of ethyl methyl carbonate (EMC) containing 1% TMSP), as shown in Figure 3a, the DCG cathode exhibits several pairs of oxidation/reduction peaks located at 4.21/4.45 V, 4.37/4.58 V, and 4.72/4.96 V during the anodic/cathodic scans in a high voltage range of 3−5 V. The areas of these peaks at various scan rates are larger than that for graphite (Figure 3b), revealing better transfer kinetics of DCG cathode for graded intercalation/deintercalation of PF 6…”

“…It is known that nanodiamonds (NDs) with unique properties of superhardness, high thermal conductivity, chemical inertness, tunable surface structure, small-size effect, and high selective absorption for alkali metal ions, etc. have been proposed as a multifunctional additive for greatly improving performances of LIB and SIB. − In this study, we synthesize ND-modified crimped graphene (DCG) as dual-carbon electrodes and introduce fluorinated NDs (FDs, Figure S1) in electrolyte (FD-electrolyte) to assemble DIBs. Based on these strategies, the performances of DIBs are significantly improved, achieving record specific capacities of 1121 mA h g –1 for anode and 149 mA h g –1 for cathode (at a current density of 0.1 A g –1 ).…”

“…5 By examining the electrochemical properties, in situ XRD patterns, morphology evolutions, and XPS bonding features of the DCG cathode with the FD-electrolyte during the cycling processes (Figures S9−S12), it is demonstrated that the FD electrolyte can lead to significantly enhanced capacities, cycling stability, and rate performance. The promotion mechanism is attributed to several factors, (i) the formation of highly efficient and stable ND-rich CEI and SEI resulting in long-term cycling stability; 27 (ii) FDs increase the amount of unsaturated and suspended bonds of EMC molecules in electrolytes, facilitating its decomposition and further enhancing the solvation/desolvation ability of the electrolytes (Figure S13); 41 (iii) FDs significantly reduce the decomposition of electrolyte salt during cycling since its F component can participate in forming SEI/CEI instead of LiPF 6 (Figure S12); (iv) more active sites of electrode are activated during the cycles in FD electrolytes.…”