Road vehicles can expend a significant amount of energy in undesirable vertical motions that are induced by road bumps, and much of that is dissipated in conventional shock absorbers as they dampen the vertical motions.Presented in this paper are some of the results of a study aimed at determining the effectiveness of efficiently transforming that energy into electrical power by using optimally designed regenerative electromagnetic shock absorbers. In turn, the electrical power can be used to recharge batteries or other efficient energy storage devices (e.g., flywheels) rather than be dissipated. The results of the study are encouraging -they suggest that a significant amount of the vertical motion energy can be recovered and stored.

The densities of states for the TI-band of single graphene sheets with small diameters were calculated by employing a linear combiriation of atomic orbital approach using as the basis set the carbon p. atomic orbitals together with a modified Huckel approximation wherein the overlap integrals out to the fourth nearest neighbors set were included.These densities of states were used to predict the voltage of lithiated carbon vs. lithium metal, an important characteristic for disordered carbon used as the negative electrode in rechargeable lithium-ion batteries. Calculations were made for isolated single graphene sheets, C0, with n = 24, 54, 96, 150, and 216. The results suggested that the lowest voltage should occur for lithiated carbon electrodes composed of single graphene sheets with the smallest diameter ( 0.7 nm for C24).Disordered carbon has two important electrochemical properties which have attracted considerable interest for its use as the negative electrode in rechargeable lithium-ion batteries3: (i) a relatively high reversible charge capacity (more than one lithium ion can be inserted per six carbon atoms, i.e., x> 1 for Li,C6, thereby exceeding the capacity of classical graphite intercalation compounds (GIC), for which x,4, = 1); and (ii) a low voltage (<0.3 V vs. lithium metal) for much of the range, x> 0.3 (which is similar to the low voltage profile found for GIC.In papers by the Simon Fraser University group,13 the high charge capacity for disordered carbon was accounted for on the basis that single layers of graphitic carbon (graphene sheets) have twice as many low energy lithium sites as would be the case for multilayered "thick" graphitic carbon (graphite molecules for which the c-axis dimension, L0, is >> 0.335 nm, the interlayer distance between layers in graphite).Thus, for graphene sheets one expects Xm = 2.If one takes this reasoning a step further, additional capacity may arise from low energy edge sites for lithium ions, such that x,,,, > 2 may be expected for small diameter graphene sheets, C0, for which there are relatively many edge atoms. For example, at least half (12 out of 24) of the carbon atoms in C24 are edge atoms, (the relative number depends on how one defines an edge atom; in this paper they are defined as atoms with only two nearest neighbor carbons); and if one assumes one low energy lithium site for each edge carbon atom, this allows for a maximum in xof x = 4, i.e., * Electrochemical Society Active Member.Li4C6 may accrue, suggesting the possibility that small diameter graphene sheets may provide a high charge capacity. This leads to the question: would there be a sacrifice in voltage for such a material? To answer the question we carried out a set of density of states (DOS) calculations for planar molecules of homologous symmetry, C0, for n = 24, 54, 96, 150, and 216. Illustrated in Fig. 1 are the first three members of this group. A linear combination of atomic orbitals (LCAO) approach was employed, using as the basis set the carbon p atomic orbitals, together with a m...

LiPON films have been produced by nitrogen ion beam assisted deposition ͑IBAD͒ of thermally evaporated Li 3 PO 4 . This process allowed us to rapidly deposit X-ray amorphous LiPON films with densities close to that of the handbook value for Li 3 PO 4 , high ionic conductivity (1.6 ϫ 10 Ϫ6 S/cm), electronic conductivity smaller than 8 ϫ 10 Ϫ13 S/cm, and an electrochemical stability window of over 6.0 V. These properties, combined with the high deposition rates that can be achieved with this process (Ͼ1.0 nm/s), make it an attractive candidate for industrial production of LiPON thin films for Li-ion batteries.Nitridation of phosphate glasses is known to increase their chemical stability. [1][2][3][4] reported on the production of lithium phosphorus oxynitride ͑LiPON͒ thin films deposited by reactive sputtering of Li 3 PO 4 in a nitrogen atmosphere. These films were both more electrochemically stable ͑5.5 V stability window vs. Li/Li ϩ ) than their non-nitrided counterparts and exhibited a 40 times higher room temperature Li-ion conductivity of 2 ϫ 10 Ϫ6 S/cm. 6 This has led to much interest in using LiPON as an electrolyte for solid-state lithium-ion thin film batteries. [7][8][9] Since the conventional means to deposit LiPON films, sputtering, is a relatively slow process, we decided to explore the use of nitrogen ion beam assisted deposition ͑IBAD͒ of thermally evaporated Li 3 PO 4 as a possible improved process. In this paper, we present a brief description of this process and a summary of our results for two representative films. We show that the process provides for significantly higher deposition rates and gives films with equivalent, if not improved, electrochemical properties. The process has the additional advantage that, at least in principle, it allows one to readily vary the amount of incorporated nitrogen by simply adjusting the ion beam gun current. The main drawback of the process to date is a residual, largely thermal ͑mostly determined by substrate temperature͒, tensile stress that the LiPON films exhibit after their depositions. Cracks arising from this stress have been identified as a major cause of electrical shorts that occasionally are found in asdeposited cells that use LiPON as their electrolyte. 10 ExperimentalThe base pressure of the vacuum chamber in which the films were deposited was 4 ϫ 10 Ϫ7 Torr. Pressed pellets of Li 3 PO 4 ͑Alfa͒ were placed in an electrically heated tungsten boat ͓purchased from Mathis, reference no. S36.010W͔ and were melted during the pump-down and chamber bakeout ͑for Ͼ48 h at approximately 150°C͒ prior to the deposition. The sample holders were part of a planetary system that allowed the substrates to revolve and rotate above the centrally located source to ensure a uniform thickness. The throw distance between the source and the samples was approximately 22 cm. During deposition the substrates were simultaneously bombarded with nitrogen ions provided by a Commonwealth Mark I ion gun, placed to one side of the chamber. The ion gun center was at the same height ...