Rechargeable batteries are the primary electrochemical devices that provide electricity for net grid supply and renewable energy management during off-wind and solar at night, and they provide a resilient infrastructure for electric vehicles and consumer electronics. Hybrid and solid state batteries rely on solid electrolytes that unlock through the application of Li metal anodes, boosting gravimetric and volumetric energy density by approximately 35% and 50%, respectively, compared to classic lithium-ion batteries (LIBs) [1]. Despite the rich plethora of Li-oxide based solid electrolyte chemistries with high stability towards metallic lithium, critical current densities set the upper limit and are also on a material subject to local variations over chemistry fluctuations and microstructure [2, 3]. Through this work, we report that Li-garnet thin films, Li_6.5La₃Zr_1.5Ta_0.5O_12-δ (LLZO-Ta), (made by PLD process with a Li₃N substrate) reveal higher Li⁺ ionic conductivity due to right lithiation adjustment at deposition and a dopant switch towards Ta, when compared to prior Al-doped LLZO PLD films of one order of magnitude lower conductivity [4]. The here synthesised LLZO-Ta films are crack-free nanostructures (350 nm thickness) and reveal a Li⁺ ionic conductivity of 1.5*10^-4 S/cm² at ambient with an activation energy of 0.41 eV. We demonstrate that thin films with nanocrystalline grains and higher grain boundary volume can, in fact, have similar conductivity to macrocrystalline bulk LLZO-Ta [1]. In these systems, the Ta dopant concentration on the Zr-lattice site partially balances the Li vacancies and transport. Previous reports have shown that the local stoichiometries (Li, Ta on Zr, O2) can vary substantially for these Li-oxides [5]; however, the extent is unclear. We employ active ML learning and Raman spectroscopy to study over high analysed data volumes for LLZO-Ta for pellets and thin films how the local vibrational modes shift and generate 2D maps towards different microstructures and length scales. Here, we see the defect chemistry local changes the direct reactions over 2500 spectra on an analysed area of 15x15 µm² and can directly image correlations on vibrational modes. For instance, the Ta-ions and tetrahedral Li-ions share similar local segregation areas, while octahedral Li sites have an opposite trend, and we will discuss the effects of concentration changes, e.g., dopant; also, compared to a non-Li-oxide the spreads in local defect chemical changes are far wider for LLZO. Towards the end, we report on the first half of the cell tests measuring the in-plane towards Li/Li+ cycling and critical current characteristics. Collectively, our work contributes to synthesis science and understanding local defect chemistry from macroscopic to nanoscopic-grained Li-solid state electrolytes, evolving methods such as combining active ML learning with defect chemical local Raman analytics of vibrational modes. Technologically, results contribute to thin film solid-state electrolyte design strategies for hybrid and solid-state battery configurations.